Cool! I've always wanted a small lightweight Metcal supply for on-site use - SMPSU for light weight and fan cooled to minimise heatsink. Maybe even a battery option...
Do you really need the MCU?
Well, even the original Metcal RF supplies have a SMPS, at least for the RF part, as well as linear regulators for the remaining stuff.
The µC is not really needed, the feedback-loop works on it's own. However, the µC is used to give a fancy display, as well as powering up/down the RF stage. I always hated it to switch of the Metcal supply to change tips....The display on the MX5000 is nice, but in practice could be reduced to a LED that shows when power is below a certain threshold (i.e. heated up). Maybe a bicolour that did a gradual change of coluur over the power range.
What is missing is the detection whether a tip is inserted into the handpiece or not using some analogue circuitry. Right now the µC is supposed to detect a fault condition and shut down the RF stage then. Maybe i'll add some analogue fanciness, so that one can chose to leave out the µC completely but still have the RF final somewhat protected.The Metcals put some DC through the heater and use this to detect open-circuits, but an RF fault detection cct could probably do this as well as protection against shorts etc.
I don't think the frequency is that critical as far as the heater is concerned- AIUI the choice of 13.56 is just to keep it in the ISM band.
But then, this all are just the first steps and thoughts. Any input is welcome, of course. I hope to have some initial schema and layout ready to upload here in one or two weeks. Right now thermal recovery is not as good as the original. But i mostly blame that on the 11 MHz instead of the 13.56. After all, that's about 20% off the target frequency.
The STSS and MX500 use a huge, heavy mains transformer - only the MX5000 uses a switchmode mains supply, but it's still in a heavy cast case.
The display on the MX5000 is nice, but in practice could be reduced to a LED that shows when power is below a certain threshold (i.e. heated up). Maybe a bicolour that did a gradual change of coluur over the power range.
Auto-reset on error is certainly useful.
The Metcals put some DC through the heater and use this to detect open-circuits, but an RF fault detection cct could probably do this as well as protection against shorts etc.
I don't think the frequency is that critical as far as the heater is concerned- AIUI the choice of 13.56 is just to keep it in the ISM band.
As regards using a fan, this was purely to minimise size & weight, for cooling both the PSU and RF stage.
I had another thought for a more 'extreme' approach to a lightweight solution : generate the 13.56MHz direct from a rectified, unsmoothed mains supply, and use an RF transformer to do the mains isolation.
My idea was to use 24DC or thereabouts for supply. That way the output of the buck converter for the RF can't get too high at all.Looking at the MX500 schematic and description, although it feeds about 50V into the buck converter, the description indicates that the output voltage only goes to about 21V - I wonder why they used such a high input voltage, unless maybe they were initially unsureabout how much power they'd need and just didn't bother changing the design.
If the element is absorbing a lot of power I'd expect the Q is going to be pretty low, so it shouldn't be too sharply resonant.
I don't think the frequency is that critical as far as the heater is concerned- AIUI the choice of 13.56 is just to keep it in the ISM band.
Yes and no. True, it could be done with basically any frequency. However, the filters of the RF stage, plus the inductance and capacitance of the tip/handpiece are somewhat tuned. After all, the tip _is_ like an antenna to the RF output. It just happens that due to the Curie effect it will go into a mismatch once the temp. is reached. But then, i will see how it behaves once i use the right frequency.
QuoteI had another thought for a more 'extreme' approach to a lightweight solution : generate the 13.56MHz direct from a rectified, unsmoothed mains supply, and use an RF transformer to do the mains isolation.
Uh, not sure that this would be a good idea. For one, generating such high frequencies directly at these voltage levels is no simple feat. At least not if it is supposed to be efficient. The next problem is regulation. Once the tip reaches temperature, you will have a mismatch. That means that a most of the RF is reflected back into the supply. The purpose of the buck converter on that supply is to reduce the voltage the more power gets reflected. Otherwise you end up with several hundreds of volts reflected back.
If the element is absorbing a lot of power I'd expect the Q is going to be pretty low, so it shouldn't be too sharply resonant.
Yeah I doubt it's very practical... it was just a crazy idea!
Having said that, the fact that you don't need DC for heating applications, and the AC reservoir cap is one of the biggest parts of a SMPS means there might be some scope to do something interesting, even if it's just a non-isolated, buck converter followed by RF isolation, or an unsmoothed DC supply Or even just phase-angle control to use just the leading and trailing parts of the mains waveform.
I don't know enough about RF power stuff to know how practical an RF transformer at this power level with mains isolation would be.
Another approach might be to use a SMPS that has a wide voltage adjustment range, and use that to do the control, although that only saves the second buck reg which isn't a big deal in size/weight terms.
Would a fixed RF output and PWM control be another option? Could get a bit noisy I suspect!
Could you please share the schematic of power stage? RF has always been a total voo-doo for me.
I always assumed that RF-guys (plus EMC engineers) can do their work only after they sacrifice a goat/virgin/infant/whatever during full moon :) Probably some illegal substance use is also involved :) [no offense, rly, I'm impressed with your design :) ]
Wondering what material they used in the original circuit. I mean, even there the toroids do have a small diameter, and i used the same.What colour are they?
Wondering what material they used in the original circuit. I mean, even there the toroids do have a small diameter, and i used the same.What colour are they?
http://www.micrometals.com/materialchart.html (http://www.micrometals.com/materialchart.html)
Could you please share the schematic of power stage? RF has always been a total voo-doo for me.
I always assumed that RF-guys (plus EMC engineers) can do their work only after they sacrifice a goat/virgin/infant/whatever during full moon :) Probably some illegal substance use is also involved :) [no offense, rly, I'm impressed with your design :) ]
Couple of things , I have a SST unit and have not found any schematics or manual , I did check on Metcals site , but nothing as old as my unit .
On the torrides , sounds like you may not know the mix ?
I am a ham radio operator and have come across a lot of discussion of torrides , and the mix is related to frequency .
a couple of my bookmarks ,
http://www.kitsandparts.com/faq.php (http://www.kitsandparts.com/faq.php)
https://www.amidoncorp.com/ (https://www.amidoncorp.com/)
http://www.cwsbytemark.com/ (http://www.cwsbytemark.com/)
http://www.cliftonlaboratories.com/estimating_q_of_ferrite_cores.htm (http://www.cliftonlaboratories.com/estimating_q_of_ferrite_cores.htm)
Here's a pic of an old (slightly hacked) US STSS-002.
I was looking at repackaging it with a SMPS to make a smaller PSU thin enough to fit a laptop bag. I had problems with the RF upsetting the SMPSU and never got round to finishing it.Here's a pic of an old (slightly hacked) US STSS-002.
What did you do to the older STSS-002? Think it is possible to boost the power to MX-5000 levels?
Also just calculated the output power, it nicely dumps over 30 watts into a 50 ohms dummy (i have around 115 volts Vpp at the dummy), so that part is OK.Might be interesting to try measuring the actual impedance of a Metcal tip to optimise matching & make an accurate dummy load for testing.
Here's a pic of an old (slightly hacked) US STSS-002. If you want to borrow the inductors to test/compare you're welcome - not sure if I have suitable kit to measure here.
Main output device is a TO-3 IRF130 on the back.
Also a thermal image running - the hottest coil is only hitting about 35 deg.C
QuoteAlso just calculated the output power, it nicely dumps over 30 watts into a 50 ohms dummy (i have around 115 volts Vpp at the dummy), so that part is OK.Might be interesting to try measuring the actual impedance of a Metcal tip to optimise matching & make an accurate dummy load for testing.
I have an antenna analyzer , but would have to make up an adapter to the meter .
But again , I would assume [ we know what that spells ] that Metcal would make the system resonant on the one frequency it uses ?
I've uploaded some hi-res PCB pics of the MX5000 here (http://electricstuff.co.uk/temp/metcal/)
Here's a pic of an old (slightly hacked) US STSS-002. If you want to borrow the inductors to test/compare you're welcome - not sure if I have suitable kit to measure here.
It's already bad enough that a 13.56 MHz is so uncommon. Which is quite a surprise, given the fact that this is a common frequency (RFID uses that, for example).13.56MHz crystals are much more readily available and cheaper than oscillator modules (eg. 14 vs. 1 at farnell,cost below GBP0.50) -using an xtal with an HC04 or whatever inverter will be much cheaper and not take much space.
Have you taken the thermal images after an hour or so of the station idling? Because it takes some time for the inductors to "warm up".No - was in a hurry so only a few mins. May try again later
Looks like that http://uk.farnell.com/jsp/displayProduct.jsp?sku=1347752&action=view&CMP=GRHB-FINDCHIPS1-1007025 (http://[url=http://uk.farnell.com/jsp/displayProduct.jsp?sku=1347752&action=view&CMP=GRHB-FINDCHIPS1-1007025)]ixys 1xfh12N50F[/url] part is the main output - Ixys parts are popular for solid-state tesla coils.
Now _that_ is very interresting. It seems that in this unit they also used T80-6 toroids. Yellow, with gray side, and the size seems to be that of the T80 (0.8"). Also an IRF510, but not as the final i think, but as a driver. More SMD capacitors instead of all-THT-mica.
The question is just how the tip cartridges will handle that in the long term. And then, i see no real need to do that anyways. I can live with 6 seconds heat-up time. Bringing it down to 5 or 4 serves no real useful purpose, IMHO. What is a real gain is the fact that you can now change the tips without having to power-cycle the supply. Just pull the old one out and insert the new one, that's it.Reducing peak draw from cold may also be useful for SMPSU sizing and possible battery operation. I also wonder if teher is scope for fairly slow PWM control instead of analogue to simplify control. I'd think something like 50-100Hz wouldn't produce much in the way of sidebands etc, while still retaining fast response.
The toroids have a different color. Seems that Metcal was also trying to figure out which ones work best.Or maybe just a different supplier
13.56MHz crystals are much more readily available and cheaper than oscillator modules (eg. 14 vs. 1 at farnell,cost below GBP0.50) -using an xtal with an HC04 or whatever inverter will be much cheaper and not take much space.
Interesting to note The SMD caps are white instead of the usual brown - oddball dielectric perhaps? Also interesting that they are using quite a few different values in parallel - I wonder if maybe this is to reduce self-resonant effects.
Reducing peak draw from cold may also be useful for SMPSU sizing and possible battery operation. I also wonder if teher is scope for fairly slow PWM control instead of analogue to simplify control. I'd think something like 50-100Hz wouldn't produce much in the way of sidebands etc, while still retaining fast response.
or use the osc on a PIC12 or ATTiny - smaller than a HC04, and you get some simple control functions for free (auto-reset, powerdown timeout, startup current limit.)13.56MHz crystals are much more readily available and cheaper than oscillator modules (eg. 14 vs. 1 at farnell,cost below GBP0.50) -using an xtal with an HC04 or whatever inverter will be much cheaper and not take much space.
True. Maybe i go for that, if board space allows. Right now it's rather crammed, but i should be able to make some space for that.
The number will be to get current handling - don't have it in front of me but I think there were 3 or 4 different values. Could be to balance qties used in the BOM but considering other cost-inefficiencies (e.g.RTC and use of TH where SMD could have been used) it seems unlikelyQuoteInteresting to note The SMD caps are white instead of the usual brown - oddball dielectric perhaps? Also interesting that they are using quite a few different values in parallel - I wonder if maybe this is to reduce self-resonant effects.
Well, either that or to get the proper value out of a combination, and also for current handling capacity i think.
I suppose worst-case when you hit a heavy tip to a groundplane is the most significant limit - if this is a lot lower than cold then it may be worth looking at some sort of startup current limit.QuoteReducing peak draw from cold may also be useful for SMPSU sizing and possible battery operation. I also wonder if teher is scope for fairly slow PWM control instead of analogue to simplify control. I'd think something like 50-100Hz wouldn't produce much in the way of sidebands etc, while still retaining fast response.
Right now it draws up to 2.3 amperes during heat up for a few seconds, at 26 volts supply voltage. It drops to about 700something mA once the tip reached it's temperature.
You can't really PWM regulate that thing, i think. What it does is to pick up the peak voltage right before the last output filter coil. It then tries to keep the voltage at that point constant, by feeding that back into the buck regulators feedback pin. The principle here is that if the load matches (i.e. cold tip), the voltage before and after that coil are roundabout the same. The hotter the tip gets, the more of the RF power is reflected back. That means that after that coil the voltage drops, while before it will rise. But since that is in the feedback loop, the buck will lower the output voltage, and thus reduces power fed into the cartridge. And, of course, it keeps the final from going up in smoke: that reflected power would cause a voltage increase there as well, effectively destroying it if there was to be no regulation.I didn't appreciate the voltage issue though - was thinking in terms of heat only.
or use the osc on a PIC12 or ATTiny - smaller than a HC04, and you get some simple control functions for free (auto-reset, powerdown timeout, startup current limit.)
I didn't appreciate the voltage issue though - was thinking in terms of heat only.
It might be viable if you took more control of the loop - would maybe need to take the buck reg into a microcontroller. I supppose you could integrate some current limiting into the buck.
Do you have an enclosure in mind? It's always easier to make a PCB fit an enclosure than find an enclosure to fit an arbitarily designed PCB.
Ahh, well, the dreaded issue of enclosures.tell me about it - I've spend way too many hours of my life finding just the right one...
In the past decades i found that it is close to useless to design DIY stuff for some specific enclosure. The markets are way too different to even come close to a common denominator here. For example, in the US market you see Hammond very often. In Europe they are more of a curiosity, however. In Germany you see things like Bopla or OKW very often (BTW, check out OKW. They make _really_ nice enclosures!), but overseas they are basically unheard of.
Nonsense - There are no significant national borders these days for that sort of stuff. All of the above are widely available pretty much anywhere. I think they all have UK offices, but as most are stocked by Farnell/E14, Digikey etc. they're no problem (at least no more than any other component) to get pretty much anywhere.
Incidentally have you done any measurements on the actual dissipated power/heatsink requirement?
Talking about DigiKey. I find their shipping costs absurd, at least last time i checked.They ship free to UK for orders >GBP50 - I think it's similar in EU
Oh, and have you ever ordered samples from Texas Instruments?Yes, but not recently - usually very quick & efficient - only issue I've had is once needing more then their max qty, so got someone else to get some as well. This was for parts that weren't in stock anywhere.
What do you expect from the lowest paid worker? Here I have difficulty getting the post on a postbox, often the wrong box bgets my mail and vice versa. I often lean in through the box and put it in the next box where it should have been.
Here a part of the application process is a reading test, because you find many with a school certificate who cannot do more than read and write their own name.......... And this after 12 years of school.
Small update: The PCB's arrived today, after the delivery guy messed it up yesterday. First he claimed my name was nowhere to be found. Then wrote a notice for the delivery attempt using a different name (from a neighbour) and put it in her mailbox. Also claimed my name was nowhere on any of the mailboxes here. DHL Express, my ass ;(
Greetings,
Chris
Nice looking boards :-+ Are you going to sell some?
Awesome project! Always looking forward to the updates and definitely jumping on one of those boards!
Damn, this is looking good, i'm going to start looking at enclosures :P Speaking of, can you extend the leads on the main FET so it can be mounted on a heatsink elsewhere? Or will the extra inductance mess with the switching?
Also, you say it can run from 24v, but you suggest 26-28v, do you have a definitive voltage and current spec or is this coming?
Sorry about all the questions :P I'll keep an eye out for the documentation :P
Something I was considering is making something for field use to run off a laptop PSU (typically 19V), so you'd only have to take one PSU with you.
This would probably need a buck/boost topology, or a pre-boost stage, complicating things....
That FET is running at 13MHz, so extending the leads is a no no.Yeah, i doubted it would, but worth asking anyways, the reason I asked was so I could think of enclosures and heat sink designs for minimal space, 10x10x2.5 is pretty large and heavy for a portable device, If I cut the size and weight down with a smaller heat sink and a fan you could easily offset the extra power consumption with more batteries or a tiny bit larger power supply... Hmm... Maybe I could get a notebook heat sink, add a little fan, bend the heatpipe a little... hmmm... i'd be very much interested in buying/building up one of these, anyway, don't take this the wrong way, i'm like a little kid thinking of things he will do with his birthday presents before he gets them, hopefully you understand.
Something I was considering is making something for field use to run off a laptop PSU (typically 19V), so you'd only have to take one PSU with you.
This would probably need a buck/boost topology, or a pre-boost stage, complicating things....
Something I was considering is making something for field use to run off a laptop PSU (typically 19V), so you'd only have to take one PSU with you.
This would probably need a buck/boost topology, or a pre-boost stage, complicating things....
It just occurred to me that maybe it is possible to wind the RF transformer a bit differently. Right now it uses a bifilar winding, that is basically two windings with the same number of turns. Maybe the output winding could get a few more turns to transform it up a bit more, thus making up for a lower supply voltage.
Greetings,
Chris
I was thinking more along the lines of making it work with the laptop PSU that's probably already going to be in my bag, so would need to match that. Running off a laptop or power drill battery would also be a nice option, but that would certainly need some boost.QuoteSomething I was considering is making something for field use to run off a laptop PSU (typically 19V), so you'd only have to take one PSU with you.These universal laptop supplies which have a switch to select the voltage can usually go up to 24 volts. And it should be rather easy to hack them to produce 26 volts, if needed, i think.
This would probably need a buck/boost topology, or a pre-boost stage, complicating things....
Thinking about it, it should be pretty easy to use a boost reg instead of the buck for operation at lower voltages. What's the lowest regulator output voltage when idling?
Also, any chance you could measure the power draw from the 5V and 12V rails?
Is there any need for the fwd/reverse power measurement part other than debugging? What's the reason for it being the length it is?
Nice :)
I just got a Metcal handle, tweezer and a pile of unused tips for free.
With this project I can get them into use :)
Nice :)
I just got a Metcal handle, tweezer and a pile of unused tips for free.
With this project I can get them into use :)
That's great! Just make sure that the stuff is for the 13.56 MHz system. They also have a 455 kHz system, those things will not work on this supply.
Since i don't have such a system myself, i also can't adapt this circuit for it. My guess is that basically just the oscillator need to be changed and the xformer and filter section adapted to the lower frequency.
If anyone wants to jump in and work on that it would be great.
Greetings,
Chris
I's a standard F type, as used on cable/sat Tv so easily obtainable.Nice :)
I just got a Metcal handle, tweezer and a pile of unused tips for free.
With this project I can get them into use :)
That's great! Just make sure that the stuff is for the 13.56 MHz system. They also have a 455 kHz system, those things will not work on this supply.
Since i don't have such a system myself, i also can't adapt this circuit for it. My guess is that basically just the oscillator need to be changed and the xformer and filter section adapted to the lower frequency.
If anyone wants to jump in and work on that it would be great.
Greetings,
Chris
They are for MX-500 so should work.
Is the connector some standard model or Metcal proprietary?
A few typos in instructions :
Inductor is SRR1260 not SSR1260
Full partno for IC1 is LM22676TJ-ADJ
What tolerance would you suggest for the NPO caps?
Since i am not a RF guy, the output filter is something that probably can be refined somewhat. If anyone has the proper knowledge and wants to build such a unit, it would be great if you could look into that. The goal is to get the maximum possible output voltage swing for a given supply voltage from the buck converter, while keeping the output waveform as sine-like as possible.I would think max power as opposed to max peak-to-peak would be the optimum, depending on how far the waveform shape deviates from a sine.
I would think max power as opposed to max peak-to-peak would be the optimum, depending on how far the waveform shape deviates from a sine.
I'd guess you may also get more power with no filter at all, as well as a ton of noise!
Once I start playing I'll hook up a specrtum analyser - this may be a useful away to tweak filters.
I was looking for enclosure and found WAG 100.
http://www.fischerelektronik.de (http://www.fischerelektronik.de)
Can you sign me up for a set of boards when you get more? :-+
I was looking for enclosure and found WAG 100.
http://www.fischerelektronik.de (http://www.fischerelektronik.de)
Can you sign me up for a set of boards when you get more? :-+
Thanks, but i'm not sure that i will get another batch done. My main goal was to get myself another supply for my Metcal handpieces, and also to get a usable circuit out in the open. Considering what it had cost me so far i could have gone and bought a used STSS, or even two of them, but where would be the fun in that ;)
In any case, the current supply/controller board would have to change then anyways. Right now i used parts that i had at hand. The result is that the DC/DC converter circuits there for the +5 and +12 volt rails are extremely oversized. On a redesign i would go for a 12V switcher followed by a 5 volt linear regulator. Also i made a stupid mistake on them. I connected the boost/limit trimpots to GND on one side, while it should have been open there. Plus i forgot two series resistors after them. While all that can be corrected on the actual boards, it's something that should change for the next version.
But as said, not sure if i will get another batch produced. If anyone is willing to jump in on that, be my guest. I will definitely change the circuitry/layout to reflect these changes, so that someone else can have batch done. After all it's not that expensive, it was 35 US$ per 10 boards in red at iTead, plus a bit over 30 US$ for the DHL express shipping. Oh, and plus taxes of course...
If i should decide to have another batch done, i'll surely give some notice here ;)
Greetings,
Chris
Thanks for sharing the project! Sounds like a really challenging job so I'm sure you were really satisfied when you melted some solder for the first time :)
If you make the mods and release the gerbers I'll get a batch done at itead and sell the rest to any aussies interested, I think it is only fair I add $5 to the cost of each board set and send the proceeds to you. Do you have a paypal account?
Any ideas for a switch? I would like to have two connectors and a switch between them.
The schematic got multiple sheets. Is it done with eagle hobby or standard/pro license?
I could do a fixed version with eagle. Just need to go trough the thread for all changes/bugs.
But as said to cwalex, i have most of the changes already done, so you don't really need to work on that. I'll look forward to get the updated stuff uploaded here ASAP.
Hi Chris,
Have you had a chance to fix the board yet. I don't use eagle but if you just upload the gerbers I will just send them as is to itead. Hope you don't think I'm trying to rush you, I just thought I'd check in and see how you got on.
cheers,
Alex
Hi Chris,
My boards just arrived safely here in Portugal, they look great, ones again thank you very much.
...
Paulo Almeida
Chris,
This is, in my opinion, by far the coolest project I've seen on this forum, and the coolest I've seen in a long time, based on its general utility. And very nicely thought out with the self-contained RF module and the optional controler module.
Very well done!!!
Hi everyone,
here is my fist take on te controller board now compatible with Arduino based on the ATMEGA 328P-AU.
Attached is also the Firmware for the ATMEGA.
Paulo Almeida
Hi Chris,
I just finished the assembly of the first part of the RF Stage board and I’m getting 12.35 volts at the output of L2, do you think its ok?
Paulo
This project would be cool if it can be made to run on 12VDC for field work ;-)
If I ever get time, what I'd like to do is use a buck/boost front end so it will run from either a 12V-ish battery or a 20v laptop charger. I also want to do the regulation & PWM on a MCU to slash the parts count & cost. May be a while though....This project would be cool if it can be made to run on 12VDC for field work ;-)
From what i understand, Mike (mikeselectricstuff) wants to check the circuit to redesign it for 12 Volts. Basically it's just replacing the DC/DC converter with a boost converter type, instead of the buck converter it currently uses.
Greetings,
Chris
Can I use this IRF520 instead of the IRF510?
http://pt.farnell.com/international-rectifier/irf520npbf/mosfet-n-to-220/dp/9103031 (http://pt.farnell.com/international-rectifier/irf520npbf/mosfet-n-to-220/dp/9103031)
Paulo
Here are my new coils, nice and tight. ;)
Paulo
My caps meassure around 61 pF.
Paulo Almeida
P.S. Why you use IRF510?
It has a 0.5ohm internal resistance, may be something similar to IRFb4019 with 0.008ohm be more efficient?
P.P.S. Sorry, IRF630/IRF640/IRF740 i mean. Still, it is a UHF modulator ;)
May be you got fake FETs? At the photo your IRFs looks slightly scratched (like scratches from sandpaper), it get me think, that is a fake.
I think the problem are the FETs, I ordered some new IRF510 from Farnell and I also got one IRF620, I will try that tomorrow, after I replace The driver and Q2.
Paulo
Guys, i am not a guru in RF technics, but here is an idea: do you think about SWR in this case?
Hi,I haven't read through the thread, but I did see a circuit with a IRF510 going to a transformer. Is that the one blowing?
All new, same old problem, FET dies before voltage on L2 gets to 21V.
Also, testing at high output powers i drove the supply above 25 Volts, with the voltage at the drain/xfmr rising above 80 or so volts, still no problem.That is getting up towards maximum. What stops it from getting higher then 80V particularly under fault conditions? Are you getting ringing? (Which often radiates noise like crazy). I still think a snubber may be needed - or a 200V device.
Hi Richard,First start with a low supplied voltage to the mosfet, and gradually increase. Record some peak drain voltages with a known load.
so in or opinion we should replace the two 10 Ohm resistors with two 0 Ohm resistors and also replace the FET with a IRF620 for example, correct?
Paulo
Chris,
Why are the 10 ohms resistors there at all? You have a driver that has a rise fill time under 2nS and 3.5A capacity, and that is great. But then you slow it down with the 10 ohm resistors. I do not get it. I understand putting 10 ohms gate resistors in a linear circuit to prevent oscillations, but in this case, the only purpose is to make the mosfet switch slower and get hotter. Are you slowing down the mosfet so it acts as the snubber for the transformer?
Cool! I've always wanted a small lightweight Metcal supply for on-site use - SMPSU for light weight and fan cooled to minimise heatsink. Maybe even a battery option...
Do you really need the MCU?
This circuit work with Thermaltronics handle and cartridges of this ebay seller?Yes - but only the handles with the F connector (MX series) and STTC or SMTC tips.
http://search.ebay.com/?sass=denbo32&ht=-1 (http://search.ebay.com/?sass=denbo32&ht=-1)
Hi,
First, I have to thank Chris for his work. It's a great contribution to electronic hobbyst community.
Now, here is my question. Farnell doesn't have the smps chip anymore. But I've already sent the gerbers to Itead and boards are in production right now.
Can I use the lm2673 version instead of lm22676? I suppose that pin 5 should be lifted and connected trough resistor to the ground, but I'm not sure that's enough.
I've just received a response from my local distributor. They say that "our" warehouse is in Leeds and their stock is the only relevant for us. Sad.
Anyone is willing to order from germany and resend to Croatia? I'll pay in advance (paypal).
Offtopic
Re the 50€ for customs charge. The problem is only with courier post (FedEx, DHL, UPS). The have they own customs warehouses with they own customs officers employed inside so they force every single parcel trough customs. Even if customs end with zero amount to pay, you are charged with "handling and storage" fees (payable to courier) that differ from one tho another (FedEx ~50€, DHL ~30€, UPS ~30€). Ordinary post (registered, EMS) is something different. Sometimes the package get caught by customs (most often not) and I have to pay that. But much less and more transparent (10% for most things, 0% for electronics, +25% VAT for everything). In Croatia most people use couriers only once for international. After a hard lesson they use EMS :-//
Hi,
First I have to say, our friend Nyquist was making some fun with me (and the Chinese to). I'm using a cheap USB scope that's good for maybe 4MHz (never used it over 1-2MHz before) sqare wave and it's "just rounded the edges". Plus the probe is on the cheap side. Sorry guys.
The holes are vias I put there to give it a bit more strength, they are not connected to anything but the solder pad on top layer. Please don't tell me this have any effect on the RF circuitry.
The cores are from kitsandparts, exact same as you ant Paulo used. The windings are as in your manual, carefully put together and checked for short. If the cores are not good for a given F, they would most probably overheat - is this correct?
Hmm, OK. Not Nyquist, but bandwidth limitation. I would suggest that you use a "real" scop instead, with at least 20MHz bandwidth. Who knows if the voltage levels it shows are correct, when it already messes up the waveform so badly.I'm using a Hantek DSO-2090 40MHz, 100MS/s. Last night I've made made a test - I've set up a 50MHz ARM microcontroller clock output to one of it's pins. Started with 50MHz all I got was a nice 50MHz sine wave. By decreasing a clock little by little the usable shape showed up at 4MHz. It's time to buy a new scope I think |O
In any case, the output of the driver shoud reach roundabout 12V p-p. What you have there is much too low (if that reading is correct), meaning that the FET can not turn fully on.By now I can say that the reading IS incorrect for sure. I'll try to get access to something better this week.
Alright. As long as they don't touch anything at the bottom that should be no problem.They are not touching anything. Maybe the via stubs add up a little bit of capacitance, but not much.
Well, that's the thing. The ones that Paulo got first turned out to not work that well, while it was claimed that they are equivalent. Once i sent them a set of cores from the exact types i use here, it worked for him as well.I have this from kitsandparts:
The cores are good for a rather wide frequency range. However, small differencies in material composition can have big effects. RF is a nasty thing when it comes to such things...
Also note that later i updated the docu, so the number of turns for each core changed. If you used the very first one i wrote, it will be slightly off.Used the docu from post #68.
That does not sound right at all. Without load (i.e. no FET connected) it should not get hot, not even really warm, no matter if there is thermal paste or not. That, in combination with the awkwardly low output level you get from the driver, tells me that there is something wrong. Either with the supply voltages or with the solderwork on the circuit itself. Maybe soldered in a wrong (too low) value for R10, the pulldown connected to the FET's gate? Is the supply voltage to the driver a clean 12V DC?Tonight I'll put together a new board and see how it behaves. Maybe there is some residue left from soldering - any kind of mess can behave badly in RF world. When I say'd no load I meant without R8 and R9 populated - R10 should have no effect at all.
Unless you know what you are doing, using a tip to setup the circuit is a bad idea. If it drives the output stage too hard (improperly adjusted R19), it will almost instantly kill the FET when the SWR goes up (tip is hot).It does not heat the tip, only the FET |O But it clearly does something RF, because my hot-air station switch on when RF power is enabled. At least I can use it as remote control for hot-air.
You should also limit the output voltage from the dc/dc converter to a lower value using R32 first during testing. That will help to protect the FET bit in case something goes wrong.What level you suggest? 12V or more?
Can you upload an image of the bottom of the PCB you have?Tonight. I can send you the gerbers if you wish, but I will not upload them to public until the board is working.
Hi Chris,
Attached is the bottom side of the board, as you asked.
I will send you sample cores. Just give me your mailing address in pm.
1) This PSU and the Metcal one both regulate based on Peak voltage at a certain point in the filter, It seems to me it should also work regulating for constant RF current or perhaps for constant reflected power. Does anyone see a problem with either of those?
2) Power requirements - I've seen 100V Peak mentioned during heating, so 100 Watts for a few seconds assuming the tip looks vaguely 50 Ohms below its Curie temperature. The SWR vs time graphs are very nice but would it be possible to plot some Power vs time for typical usage, or perhaps post the raw data so I could have a go at estimating it.
3) What does the tip really look like in impedance? [...snip...] (or do the tips have a small capacitor to resonate out the L?).
My current thinking is to full wave rectify the mains supply to get a 350V dc bus and run a small non-isolated switcher off of that to power the control circuitry. I plan to generate the RF directly from the high voltage dc and provide the output isolation and much of the matching via a suitable RF transformer. I'm currently toying with the idea of using a pair of line output valves for the high voltage RF source - designed for switching, suitable for the peak voltages expected, tolerant of overloads on timescales of ten seconds or so (tip heatup time), generally bombproof. What's holding me back at the moment is not really knowing what the load is like, and being a little unsure of the best parameter to regulate for.
I think you got the numbers a bit wrong...Oops, somewhere along the way I'd read that as peak rather than p-p. That makes things a bit easier.
Good question, and i simply don't know what the real tip cartridge characteristics are. I dont have the equipment to test that.I have the equipment to measure it (I can do it at work), cold characteristics are easy anyway. Hot measurements might end up being a bit crude. Looks like the first thing I should be doing is buying the handpiece and tip :).
While it would probably look nice with tubes, i'm not sure that it is really practical. [snip] Also keep in mind that other countries have different line voltages.I'm well aware of the disadvantages with a tube based output stage but I do like the idea of using the RF transformer for isolation. Given there are only really two line voltages in common use worldwide I would imagine a switchable doubler similar to older computer PSUs would be fine, smaller variations would then be ironed out by the feedback loop. Of course a modern design with a power factor correction switcher at its input inherently produces a stable dc bus from a wide range of supply voltages.
Chris,
Thanks for the reply, the patents look very useful. I'll need to think about the voltage to current conversion, it's not really clear to me yet how that works. I've not yet decided between that approach and regulating the current directly - probably with a current transformer based measurement.
My metcal handpiece just arrived and I was somewhat surprised by the connector. I *think* it mates with a normal F-type but it's not threaded, it grips with some kind of collet. Is this normal?
If it does fit the F to N type adaptor I have then I should have some impedance mesurements by the end of today.
Just in case:My thinking was to integrate the PSU, user interface, oscillator etc. using a MCU, promarily to minimise the part count - Microchip have recently brought out a PIC with built-in building-blocks for switchmode PSUs - I've not looked at it hard enough to see how useful it would be for this.
http://dangerousprototypes.com/2013/05/28/diy-metcal-13-56-mhz-rf-supply/ (http://dangerousprototypes.com/2013/05/28/diy-metcal-13-56-mhz-rf-supply/)
A few things... For a few days i'm thinking where to go next with this project. There are several, not mutually exclusive, options:
- Single board design that has everything on one PCB
- A version that uses a boos or SEPIC converter, so it could work, for example, with a 12V supply
- One that has "no frills", that is, basically just the RF board designed to work on its own from a single 26V minimum supply
What do you folks think would be usable? In case of the boost/SEPIC option, i would rather prefer the SEPIC variant: This would allow to use a wide range of input voltages, below, equal and above to what the RF stage would need. However, i'm still looking for a suitable converter chip. Since the buck version already eats up to 3 amperes at 30V input, i think that a suitable boost/SEPIC would have to be able to at least handle 5 or 6 amps.
A "no frills" version would result in something like the old RFG3/STSS styles of supplies, that is, no sleep/boost mode stuff, no auto-off, etc. Only the tip-detection would still be there (and of course, still would not require a power-cycling as with these old original units).
What do you folks think about the placement of the output FET? Right now the whole thing is made so that it has to sit flat on a heatsink. Of course it can be made so that a heatsink has to be mounted vertically to the board.
Let me know what you guys think/want/prefer, and i see forward to it that the next step will include that as much as possible ;)
Greetings,
Chris
| R | X | Equiv X | SWR | S11 | |
| Cold: | 42.3 | +13j | 153 nH | 1.4 | -16dB |
| Warm (but below Curie temp): | 55 | -16j | 730pF | 1.1 | -23 dB |
| Hot (above Curie temp): | 12 | +24j | 280 nH | 5.1 | -3.4 dB |
I'm wondering if any of the many available coax sockets can fit on the cartridge. Then use a 3D-printer to make handpieces....Recently, I've got a "solar charger" from ebay (don't ask why). It came with a lot of different connectors, one of the barrel shaped fits nicely to the cartridge.
Hi,Hi Laumingis,
Done some measurement with osciloscope, without R8, R9 (they were not soldered in my first post also).
Power supply measurements are with only one driver input connected: then chip gets only slightly warm. I guess I'll proceed from here and try to connect FET to one output only.
Hi,
Done some measurement with osciloscope, without R8, R9 (they were not soldered in my first post also).
Power supply measurements are with only one driver input connected: then chip gets only slightly warm. I guess I'll proceed from here and try to connect FET to one output only.
--
Laumingis
I'm going to embed the whole system in a single psoc and I'll use a full bridge rf inverter with filtered output to avoid "from no load to load" changes in the output.
A shunt resistor or a hall sensor to measure the current the output uses will tell me the power output. (If current is constant, then a voltage divider)
What do you think? Did you try anything similar?
What do you think about this minimonster for the full bridge?
IRFB4212PBF
When you talk about constant current, how much is that constant current? As Metcal talks about its constan current I need to know if it's fixed.
And Peak-to-Peak voltage at max load (heating up)? I hope the max power output depends on max voltage in the current regulator.
I have another question,
why didn't you use for L3 L4 and L5, 560nH 780nH and 250nH rf power inductors?
The RS code for the transformer is 467-4267
I've been Reading problems about power losses in the switcher. Why dont you use a good TVS?
A RC snubber could have resonation related problems (if it's not well calculated as in the 99% of the times).
On the other hand a good TVS will continue to dissipate the exceeding power in the other case the resistor, the transistor and the esr of the capacitor would dissipate.
For example SMAJ110A, the parasitic capcitance of the diode is nearly null for the application.
I saw another thing, in the toroids I saw no litz wire, the wire diameter you use is a waste for 13.56MHz due skin effect in the conductor and so the DC resistance is really higher tan you expected, lowering the overall efficiency.
Thank you for your time, first of all "from load to no load" I meant when you take out the tip, in a constant current regulator the sudden change in an open circuit tends to overshoot the voltaje too much.
What "from no load to load" changes are you talking about?
I'm not convinced that it is necessary to use a full bridge in this application. Not only does it introduce more parts in the output driver stage that can fail, it also would require more power in the driver to drive the FET's (assuming you want FET's in the full bridge).
You did notice that this FET ist for digital audio amplifier applications, right? And you also notcied what they show in the datasheet for the gate charge and input/output capacitances? Also, during heatup the RF voltage is way over 100 volts, i doubt that a 100 volt FET is the best choice in such a bridge, if you want it to drive the tip cartridge more or less directly.
I lack the tools to do any RF meassurements that go beyond looking at the output waveform on a scope. But generally i assume that "constant" somehow means "fixed", because otherwise it would be variable, right? But then i think that there is more to it than just constant current. This is RF, were we have to deal with stuff like impedance mismatch and thus reflections when the tip changes temperature, the latter being able to easily kill the RF final FET. But then, i'm not a RF wiz, so it is quite probable that i misunderstand a few things.
I thought about using ready made inductors. But they are much harder to get than standard toroids that are on the market for decades already, and thus have a really good availability. Plus, during development of the circuit it is much more useful and cheaper to simply rewind a toroid instead of buying lots of different fixed value inductors. Keep the DIY aspect of this in mind. It is important to use parts that have a rather good availability. Generic standard toroids and a bunch of magnet wire is far easier to get than some specific type and brand of fixed RF inductors. And most likely much cheaper too.
Thanks for proving my point about standard stuff. That part is no longer available at RS in Germany, for example. It says that they no longer have it in their product line. So it's just a matter of time until it is no longer available at other RS outlets as well, i guess. OTOH, the T-* and FT-* toroids are supposedly more standard (although there have been problems), and are on the market for a really long time by now.
What power losses in the switcher? You mean the DC/DC converter? Or the RF final? The DC/DC is just fine, and normally so is the RF final once the right parts are used in the output filter stage.
Too bad that there is no RC snubber to be found anywhere in this circuit.
So, in a constantly running RF circuit you propose to use a TVS that has a 0.01% duty cycle specified? The whole point of the circuit is to have a control loop that avoids generating excess RF power in the first place.
You did read the thread, did you? You had a look inside an original Metcal unit, right? You looked at, lets say, 50 watts HAM radio's output stages, right? Are you saying they all do it wrong by using solid magnet wire? We are not talking about hundreds of watts or even kilowatts here. Plus, the inductors don't get that hot, so there seems to be no issue there at all.
Keep in mind that one goal of my circuit was to simplify things and to use parts that are relatively cheap, trying to avoid speciality stuff as much as possible. But of course you are welcome to design your own circuit in any way you like. After all, that's the whole point of DIY.
Greetings,
Chris
Thank you for your time, first of all "from load to no load" I meant when you take out the tip, in a constant current regulator the sudden change in an open circuit tends to overshoot the voltaje too much.
A H-bridge in rf is really complicated but once done it allows you control the current directly from the bridge, the shunt resistor with an integrator would show the current. Think the integrator must not to be so fast because of the thermal inertia of the tip but fast enough to not to burn the TVS is in antiparallel with the + and the - of the bridge.
Forgive that mosfet, other talked about another much better, the IRFB4019. Note that is a "digital" audio amplifier, that means it controls the current in the speakers by varying the dutty cycle in a switching frequency much higher tan the audio frequency. Faster times, better efficiency. The mosfet I talked about was for the same purpose but its worse talking about speed and gate charge. They are designed for hard switching and that means a TVS is necessary(or a rc snubber).
I agree with you about the toroids.
Power losses at the switcher I meant the IRF510. Someone talked about an rc snubber that's all. I've seen lots of rf stages dying because of a lack of a TVS.
The control loop controls the excess of the power but it has a time constant orders of magnitude higher than the response time of a TVS. TVSs only acts when the voltage goes over a value, see it as a hyperfast zener.
Yeah they are wrong by using solid magnet wire :D but it's not a significant problem, the current is not high. Litz wire can be made with thin enameled copper wire.
The heatup time would decrease with litz wire, and the efficiency would increase. If you have the time try it! enameled AWG40 is enough. I would like to compare theory with reality :D although skin effect is reality too.
The individual strand diameter of litz wire needs to be small compared to the skin depth or else the proximity effect losses will be high. At 13 MHz the skin depth in copper is about 20 µm. AWG40 has an 80 µm diameter.
For example, a 100 strand AWG40 litz wire has a copper cross section of 0.5 mm2. If you use that you'll have a winding with effectively 10 layers and proximity effect losses will give you an Rac/Rdc of more than 100! (see the Dowell plot at http://en.wikipedia.org/wiki/Proximity_effect_%28electromagnetism%29 (http://en.wikipedia.org/wiki/Proximity_effect_%28electromagnetism%29) for example) So your 100 strand litz wire will actually have higher resistance than even a single (40 AWG) strand of the same! :o
A single layer winding made out of thick solid wire is more practical than litz wire at such frequencies.
Nobody talked about a 100 strand of foolish nolitz wire. AWG40 was just a starting point because is easy to find, better if you find a litz one.
Nobody talked about a 100 strand of foolish nolitz wire. AWG40 was just a starting point because is easy to find, better if you find a litz one.
Huh? You suggested using litz wire made out of AWG40 strands, and this was the configuration I was talking about.
According to the Dartmouth reference "Many manufacturers cannot provide litz wire using
strands finer than 48 or 50 AWG.". Even such thin strands (0.025 mm) will not be very effective at 10 MHz+ because you will need so many of them for any reasonable cross section and the proximity effect losses will be large.
while working on some magic-8-ball type of addition to the code (hey, i try to predict the actual tip....), i noticed some quite dramatic differencies between original Metcal cartridges and their Thermaltronics equivalnt. While i have only 3 types of equivalent Thermaltronic tips, the trend is quite visible!...Hi mamalala and everyone else,
Don't worry about spamming "my" work. First of all, i am not the original designer of the system used. Standing of the shoulders of others, as they say. Secondly, i very much welcome discussion of what improvements could be done to the little, simple circuit i made. And finally, since i am not an RF guy myself, i very much welcome any discussion about that stuff.
Personally? Yes, i am pretty sure that in (at least) this instance there is not much (if any) gain in using litz wire, compared to solid core wire. As said, any heatup that i could note was pretty much only in the cores themselves. This is most obvious with the transformer on the ferrite core. Simply using a bigger core got rid of most of the heat, while still using solid core wire. This is proof positive that the core itself has much more influence than the type of wire used.
Plus, most of the manufacturers of radios out there use solid core wire as well. Yea, some might say they are all wrong, but i highly doubt it. Theory is one thing, practice is another. Sure, you may get rid of a small amount of losses by using litz wire, but the cost of doing so is probably much higher than the cost of the actual losses. After all, companies are not charities. If they could make something that gives them an advantage over their competitiors, they will do it. But since rarely anyone uses litz wire in such applications, i have to assume that the cost/benefit ratio is heavily tilted towards simple solid core wire here.
But hey, that is just what i think. Build it using litz wire, and let's see how it compares. I'm always open to that kind of stuff. But you have to show me substantial data to change my mind. So, unless someone builds the circuit as is, plus another one using litz wire, and then compares them and finds substantial benefits for litz wire, i will stick to my preliminary conclusion that the type of wire simply does not matter that much, if at all.
Greetings,
Chris
Edit: To make it clear: I really mean same circuit. That is, same parts, same layout, everything the same, except for the inductors and transformer in the RF path. Then show what the actual differences are. Does it heat up half a second faster due to less losses? Does it consume a few miliamperes less current to achive the same output on the same tip cartridge? If so, what is the price difference between that litz wire and solid core? Solid core is bog standard and cheap. Litz wire, not so much. At least for RF applications. There is no gain in saving one buck in electricity during the lifetime of the thing, when using litz wire costs 2 bucks more... Heck, even if i save one buck and the litz wire costs me one buck extra, i have saved nothing at all.
Keep in mind that this project is meant to be built by others without resorting to too many exotic parts. The FET driver is already quite exotic, but still readily available. Some specific litz wire is (in my experience) much harder to come by, compared to regular magnet wire....
Maybe I'm wrong with the term "idle".
I call idle when the tip reaches Curie point, power output goes down and tip stays hot. I need some time to fine adjust the feedback but I cannot see a moment with frozen tin. If I touch a 0.4mm thick copper plane it takes 2s to adsorb the tin in the copper.
I'll give you all of the details.
As for the handpiece, the patent isLooks more like "position 80" is a feed-through capacitor with the capacitance in parallel with the tip cartridge.
http://www.google.com/patents/US4839501 (http://www.google.com/patents/US4839501)
According to that patent there seems to be a capacitor in series to the tip cartridge.
Moving to the distal portion of socket assembly 68, inner socket 78 is electrically connected by solder to a lead of capacitor 80, which in turn has its proximal lead soldered to inner wire 82 of coaxial cable of coaxial cable 54.
(https://patentimages.storage.googleapis.com/pages/US4839501-1.png)
I'm wondering if any of the many available coax sockets can fit on the cartridge.Does the tips fit an SMB or SMC female connector?
SMB series connectors
The miniature SMB connectors are used for internal connections in RF equipments with good performances up to microwave frequencies. SMB and SMC are similar and can be easily confused, SMB type has a snap-on coupling while SMC type is provided with a coupling nut like SMA. The SMB connector can be used up to 6 GHz.
(http://www.rfmicrowave.it/uploads/Connettori/SMB-connectors.jpg)
SMC series connectors
The miniature SMC connectors are used for internal connections in RF equipments with good performances up to microwave frequencies. SMB and SMC are similar and can be easily confused, SMB type has a snap-on coupling while SMC type is provided with a coupling nut like SMA. The SMC connector can be used up to 6 - 8 GHz and it is a good compromise between the SMA, from which has copied the screw coupling, and the SMB, from which has copied the small size.
(http://www.rfmicrowave.it/uploads/Connettori/SMC-connectors.jpg)
Hi AndersAnd,A DC short between shield and center pin of the F connector? Is this also true with no tip mounted?
quite possible that it is a feed-through cap. If any is there, it must be: there is basically a DC short when you meassure between shield and center pin of the F connector.
Hi AndersAnd,A DC short between shield and center pin of the F connector? Is this also true with no tip mounted?
quite possible that it is a feed-through cap. If any is there, it must be: there is basically a DC short when you meassure between shield and center pin of the F connector.
This wouldn't be explained by any capacitor as those are open circuit at DC, so is there also an inductor in parallel, to make the DC short?
Oh now I see what you mean. With a capacitor in series there would have been no DC short when you insert a tip, which is the case.Only with the tip inserted. Without it is open circuit. This is also what the type of tip-detection i implemented detects. Same is true for the Metcal Talon tweezers, just that the two cartridges there are in series. So, if there is any cap, it must be a feedthrough type, that is, the capacitance is only between center and shield. (Called "Durchführungskondensator" in German).Hi AndersAnd,A DC short between shield and center pin of the F connector? Is this also true with no tip mounted?
quite possible that it is a feed-through cap. If any is there, it must be: there is basically a DC short when you meassure between shield and center pin of the F connector.
This wouldn't be explained by any capacitor as those are open circuit at DC, so is there also an inductor in parallel, to make the DC short?
I was just assuming that the cap shown in the patent would be a regular one. But as you said (and as i noted very early on), that just can't be, otherwise there wouldn't be a DC short with an inserted tip, and an open without a tip.
Greetings,
Chris
Attached are some images about the tip connector side with caliper meassurements (not 100% accurate, had to hold the stuff in one hand, and the cam in the other...)Danke schön :-+
Greetings,
Chris
Hey, I got cheap handpiece from RS for 60€.
Here are the pics.
I modified the bypass capacitors before transformer, I put 4x100nF + 4x10nF (stacked in 2 files), 8 capacitors in total.
With 3x100nF capacitors X7R there wasn't enough. I saw it in the oscilloscope. Just between the transformer input and ground.
Curious if something similar might be done for the cheaper metcal/oki MFR units, especially as I have a full set of them (handpieces/tweezers/desoldering) :P. They do use a different (8 pin din) connector, but if the frequency/power can be boosted up to regular metcal levels via diy, that'd be quite amazing.
The supply circuit for those 470 kHz systems is pretty simple. Gerhard over at the µC.net forum has drawn out the schematics for the SP200 supply unit:http://www.mikrocontroller.net/topic/311671#3363592 (http://www.mikrocontroller.net/topic/311671#3363592). This one is the predescessor to the MFR1100 unit.
As you can see, a really simple thing.
Neat, but I have little interest myself in just making new power supplies, having a station myself already. I was more interested in getting the power up to the MX series 13.56 mhz levels while keeping all the existing handpiece and vacuum bits that I already have :D
Of course, if this is somehow possible, then it makes the cheaper MFR handpieces an alternative to MX ones for anyone looking to do a diy power supply as well.
No, the two systems are not compatible, it is a completely different frequency range, and thus the parameters that the 470 kHz hanpieces, cartridges, etc. present do not match to what would be required. Well, to be clear, it's probably possible to somehow match those two together, but this will very likely involve massive losses and thus make no real sense.
No, the two systems are not compatible, it is a completely different frequency range, and thus the parameters that the 470 kHz hanpieces, cartridges, etc. present do not match to what would be required. Well, to be clear, it's probably possible to somehow match those two together, but this will very likely involve massive losses and thus make no real sense.
Hmm, are the tip heater elements (or materials used perhaps) so different between those in MFR and MX tips that a frequency increase would result in a different curie point? Pardon my ignorance when it comes to these things, but I guess I was hoping that the tips are not really that different, and all that the higher frequency does is allow for more power, faster.
Curious if something similar might be done for the cheaper metcal/oki MFR units, especially as I have a full set of them (handpieces/tweezers/desoldering) :P. They do use a different (8 pin din) connector, but if the frequency/power can be boosted up to regular metcal levels via diy, that'd be quite amazing.The supply circuit for those 470 kHz systems is pretty simple. Gerhard over at the µC.net forum has drawn out the schematics for the SP200 supply unit: http://www.mikrocontroller.net/topic/311671#3363592. (http://www.mikrocontroller.net/topic/311671#3363592.) This one is the predescessor to the MFR1100 unit.
As you can see, a really simple thing.
Greetings,
Chris
No, the curie point of the alloy does not change, it is a fixed physical property of that alloy. The frequency itself also has little effect on the amount of power that can be transferred.
As far as the tips for the 13.56 MHz system are concerned, please look up the US patents 4,745,264 and 4,877,944. That shows you how they are constructed. You have the copper slug that makes the actual tip. On that slugs stub, inside the cartridge, is a cladding of the alloy with the curie effect. Around that you have a coil of wire, where the RF is fed into.
This means that you have an inductor there, and the RF source must match that, so that most energy is coupled into the alloy (which basically forms a short-circuited winding below the curie point). I don't know the specific construction of the 470 kHz tips. There are two different systems, one that has a handpiece with the coil, into which the tip is inserted, and another which more resembles the MX stuff, where all is in a single cartridge. In any case, assuming the construction is similar, the inductance will most likely not match to what can be used on a 13.56 MHz system.
I mean i have never tried it, i simply don't have any stuff from the 470 kHz system, so i can't try either. But consider this: Take a regular mains transformer that is designed to work on 50/60 Hz mains. Check what voltage ratio you get, and how much power it can deliver at a given input voltage. Now keep the voltage the same, but increase it to several kHz, and see how good it works. Most transformers will degrade rather quickly at higher frequencies. I would think that the same is true here. After all, the RF supply and the tip cartridge are basically a tuned circuit. Changing the parameters of the load will greatly detune it.
But as said, i never tried it. It may work, it may not work. I can's test it either, since i don't have any of the 470 kHz Metcal stuff. If anyone wants to send me a handpiece and tip, be my guest, then i will try it. But no guarantees, and the result might be a damaged tip and/or handpiece.
Plus, at least the cable running to the handpiece must be a coax, otherwise you will have big trouble when you go into the MHz range. After all we don't want the cable to act as an antenna and lose energy that way before it even reaches the tip.
Ah, I see now. That makes sense, of course.
I might be able to arrange something, but currently it sounds like a somewhat expensive (I'm in US) proposition that is unlikely to succeed :( I don't suppose it's possible to non-destructively measure the inductance?
On another note, the MFR units come with two types of tips - those where the heater is inside the handpiece, and those where the heater is inside the tip. The latter is mostly used looking similar to MX types, but MFR-H2-ST handpiece and the desoldering guns use the former. I have both types..
..but the whole thing may be moot anyway because of this - the MFR handpieces all use what seems to be a regular multiconductor cable as opposed to a coax.
And some kind of repair video involving a light bulb connected via a wire through a coil: https://plus.google.com/photos/114369772963211136986/albums/5708625608608987905/5725225535621735938?banner=pwa&pid=5725225535621735938&oid=114369772963211136986
You might be able to find more pictures in some of his albums, there's even pictures of Yellow Metcal soldering stations: https://plus.google.com/photos/114369772963211136986/albums/5708625608608987905/5856874665601731314?pid=5856874665601731314&oid=114369772963211136986
Maybe they were repainted by the owner company as anti theft protection, so they don't end up on ebay?
I'm pretty sure it's a BNC-connector and not an F-connector fitted in the one on the right. Notice the two bayonet lugs if you zoom in.You might be able to find more pictures in some of his albums, there's even pictures of Yellow Metcal soldering stations: https://plus.google.com/photos/114369772963211136986/albums/5708625608608987905/5856874665601731314?pid=5856874665601731314&oid=114369772963211136986Yes, they are cleary repainted. But you can also see that he modified one and put an F connector in there, to use the MX series handpieces. So it seems that at least that way they are interchangeable. Which may mean that just maybe the PS stuff can be used on MX series supplies as well. If they would have used a proper coax cable. Which we don't really know unless someone cuts open that cable, but i doubt it.
Maybe they were repainted by the owner company as anti theft protection, so they don't end up on ebay?
I'm pretty sure it's a BNC-connector and not an F-connector fitted in the one on the right. Notice the two bayonet lugs if you zoom in.
Googled for 'Metcal Sompong Tungmepol' (his name) and found these interesting videos on his YouTube channel.
Unfortunately he speaks Thai, so I don't understand anything he's saying:
Metcal MX 500 MX5000 Tips Operate on Metcal SP 200 http://youtu.be/DDttEAs8pZs (http://youtu.be/DDttEAs8pZs)
TORIOD FERRITE CORE 470 Khz TEST http://youtu.be/xNBsWEpcTDY (http://youtu.be/xNBsWEpcTDY)
He sure has a lot of toriod's to experiment with and it looks like he has also replaced the toriod's inside the SP200. Maybe he has changed it's operating frequncy:
http://youtu.be/wY8mSnWTlUc (http://youtu.be/wY8mSnWTlUc)
//----------------------------------------------------------------------------
// C main line
//----------------------------------------------------------------------------
#include <m8c.h> // part specific constants and macros
#include "PSoCAPI.h" // PSoC API definitions for all User Modules
#include "stdlib.h"
#include "string.h"
// you must use this lines if you used ljmp instruction at the interrupt .asm files for each module
// in this case PSoCGPIOINT.asm and IDLETIMERINT.asm
#pragma interrupt_handler TipDetectionISR
#pragma interrupt_handler TimeoutISR
unsigned int vforward;
unsigned int vreflect;
unsigned int vregulator;
float vf;
float vx;
float vr;
BYTE barvr;
BYTE idle;
int Statusf;
int Statusx;
int Statusr;
// tip detection interrupt service routine
void TipDetectionISR(void)
{
if (Tipdetector_Data_ADDR & Tipdetector_MASK) RF_EN_On();
else RF_EN_Off();
}
// gets 3 digital values of three conversions made at the same time
void Adc(void)
{
while(TRIADC_1_fIsDataAvailable() == 0){}; // Wait for data to be ready
vforward = TRIADC_1_iGetData1(); // Get Data from ADC Input1
vreflect = TRIADC_1_iGetData2(); // Get Data from ADC Input2
vregulator = TRIADC_1_iGetData3ClearFlag(); // Get Data from ADC Input3
// and clear data ready flag
}
// timeout interrupt service routine
void TimeoutISR(void )
{
RF_EN_Off();
IDLETIMER_Stop();
idle=2;
}
// sets the active status
void Isidle(void )
{
if (RF_EN_GetState())
{
//if regulator voltage does not reach 9.6V you are not soldering, you must change this value for other tips.
//or make a tip menu, as I only use 1 this is my threshold.
if (vr<9.6)
{
IDLETIMER_WritePeriod(5493); // timeout period.
IDLETIMER_WriteCompareValue(0);
IDLETIMER_EnableInt();
IDLETIMER_Start(); // stats timeout timer.
idle=1;
}
// if you are soldering automatically changes active status.
else
{
IDLETIMER_DisableInt();
IDLETIMER_Stop();
idle=0;
}
}
else if (idle<2)
{
idle=3;
}
}
// numerical conversions
void Traduce(void)
{
vf=5.00*((float)vforward)/1023.00; // do the conversion you like here
vx=5.00*((float)vreflect)/1023.00;
vr=29.1644172*((float)vregulator)/1023.00; // 29.1644172 constant adjusts value to match true rms voltage of the regulator
barvr=(BYTE)((int)(40.00*(((float)vregulator)/772.00))); //772.00 for 21V max, 1023 for 28V max.
}
//manages the LCD
void Actualizar(void)
{
if (idle==2) // timeout reached, press reset
{
LCD_1_Position(0,0);
LCD_1_PrCString("Apagado ");
LCD_1_Position(1,0);
LCD_1_PrCString("pulsa reset ");
}
else if (idle==3) // no tip detected, insert it
{
LCD_1_Position(0,0);
LCD_1_PrCString("Cartucho ");
LCD_1_Position(1,0);
LCD_1_PrCString("desconectado ");
}
else
{
LCD_1_DrawBG(1,0,8,barvr);
// "0123456789abcdef"
// "On f=1.23 x=1.23"
LCD_1_Position(1,10);
LCD_1_PrCString("V=");
LCD_1_PrString(ftoa(vr,&Statusr)); //prints a float to string conversion
LCD_1_Position(0,3);
LCD_1_PrCString("f=");
LCD_1_PrString(ftoa(vf,&Statusf));
LCD_1_Position(0,9);
LCD_1_PrCString(" x=");
LCD_1_PrString(ftoa(vx,&Statusx));
LCD_1_Position(0,0);
// prints the active status
if (idle==0)
{
LCD_1_PrCString("On ");
}
else if (idle==1)
{
LCD_1_PrCString("Id ");
}
}
}
void main(void)
{
//adc temp variables
vforward=0;
vreflect=0;
vregulator=0;
//float adc converted variables
vf=0.0;
vx=0.0;
vr=0.0;
//active status 0 ON, 1 IDLE, 2 OFF, 3 tip disconnected so OFF too.
idle=0;
//power bar filler
barvr=0;
//ensures timeout timer is off
IDLETIMER_Stop();
RF_EN_Start();
// first test, if tip connected rfON else rfOFF
if (Tipdetector_Data_ADDR & Tipdetector_MASK) RF_EN_On();
else RF_EN_Off();
M8C_EnableIntMask(INT_MSK0, INT_MSK0_GPIO); //enable interrupt for GPIO pins
M8C_EnableGInt; // Enable global interrupts CAMBIAR
LCD_1_Start();
//bar graph on lcd, only ram configuration, this line does not show a bar by itself
LCD_1_InitBG(LCD_1_SOLID_BG);
//set the power status of the gain amplifiers/buffers
PGA_1_SetGain(PGA_1_G1_00);
PGA_1_Start(PGA_1_HIGHPOWER);
PGA_2_SetGain(PGA_2_G1_00);
PGA_2_Start(PGA_2_HIGHPOWER);
PGA_3_SetGain(PGA_3_G1_00);
PGA_3_Start(PGA_3_HIGHPOWER);
TRIADC_1_Start(TRIADC_1_HIGHPOWER); // Turn on Analog section
TRIADC_1_SetResolution(10); // Set resolution to 10 Bits
TRIADC_1_GetSamples(0); // Start ADC to read continuously
//let's start
for(;;)
{
Adc(); // triple analog digital converter 3 inputs at the same time
Traduce(); // numerical conversions
Isidle(); // configures active status
Actualizar(); // screen information
}
}
; Generated by PSoC Designer 5.4.2946
;
;;*****************************************************************************
;;*****************************************************************************
;; FILENAME: PSoCGPIOINT.asm
;; Version: 2.0.0.20, Updated on 2003/07/17 at 12:10:35
;; @PSOC_VERSION
;;
;; DESCRIPTION: PSoC GPIO Interrupt Service Routine
;;-----------------------------------------------------------------------------
;; Copyright (c) Cypress Semiconductor 2013. All Rights Reserved.
;;*****************************************************************************
;;*****************************************************************************
include "m8c.inc"
include "PSoCGPIOINT.inc"
;-----------------------------------------------
; Global Symbols
;-----------------------------------------------
export PSoC_GPIO_ISR
;-----------------------------------------------
; Constant Definitions
;-----------------------------------------------
;-----------------------------------------------
; Variable Allocation
;-----------------------------------------------
;@PSoC_UserCode_INIT@ (Do not change this line.)
;---------------------------------------------------
; Insert your custom declarations below this banner
;---------------------------------------------------
;---------------------------------------------------
; Insert your custom declarations above this banner
;---------------------------------------------------
;@PSoC_UserCode_END@ (Do not change this line.)
;-----------------------------------------------------------------------------
; FUNCTION NAME: PSoC_GPIO_ISR
;
; DESCRIPTION: Unless modified, this implements only a null handler stub.
;
;-----------------------------------------------------------------------------
;
PSoC_GPIO_ISR:
;@PSoC_UserCode_BODY@ (Do not change this line.)
;---------------------------------------------------
; Insert your custom code below this banner
;---------------------------------------------------
ljmp _TipDetectionISR
;---------------------------------------------------
; Insert your custom code above this banner
;---------------------------------------------------
;@PSoC_UserCode_END@ (Do not change this line.)
reti
; end of file PSoCGPIOINT.asm
;;*****************************************************************************
;;*****************************************************************************
;; FILENAME: IDLETIMERINT.asm
;; Version: 2.6, Updated on 2013/5/19 at 10:44:39
;; Generated by PSoC Designer 5.4.2946
;;
;; DESCRIPTION: Timer16 Interrupt Service Routine
;;-----------------------------------------------------------------------------
;; Copyright (c) Cypress Semiconductor 2013. All Rights Reserved.
;;*****************************************************************************
;;*****************************************************************************
include "m8c.inc"
include "memory.inc"
include "IDLETIMER.inc"
;-----------------------------------------------
; Global Symbols
;-----------------------------------------------
export _IDLETIMER_ISR
AREA InterruptRAM (RAM,REL,CON)
;@PSoC_UserCode_INIT@ (Do not change this line.)
;---------------------------------------------------
; Insert your custom declarations below this banner
;---------------------------------------------------
;------------------------
; Includes
;------------------------
;------------------------
; Constant Definitions
;------------------------
;------------------------
; Variable Allocation
;------------------------
;---------------------------------------------------
; Insert your custom declarations above this banner
;---------------------------------------------------
;@PSoC_UserCode_END@ (Do not change this line.)
AREA UserModules (ROM, REL)
;-----------------------------------------------------------------------------
; FUNCTION NAME: _IDLETIMER_ISR
;
; DESCRIPTION: Unless modified, this implements only a null handler stub.
;
;-----------------------------------------------------------------------------
;
_IDLETIMER_ISR:
;@PSoC_UserCode_BODY@ (Do not change this line.)
;---------------------------------------------------
; Insert your custom assembly code below this banner
;---------------------------------------------------
; NOTE: interrupt service routines must preserve
; the values of the A and X CPU registers.
;---------------------------------------------------
; Insert your custom assembly code above this banner
;---------------------------------------------------
;---------------------------------------------------
; Insert a lcall to a C function below this banner
; and un-comment the lines between these banners
;---------------------------------------------------
ljmp _TimeoutISR
;---------------------------------------------------
; Insert a lcall to a C function above this banner
; and un-comment the lines between these banners
;---------------------------------------------------
;@PSoC_UserCode_END@ (Do not change this line.)
reti
; end of file IDLETIMERINT.asm
Googled for 'Metcal Sompong Tungmepol' (his name) and found these interesting videos on his YouTube channel.
Unfortunately he speaks Thai, so I don't understand anything he's saying:
Metcal MX 500 MX5000 Tips Operate on Metcal SP 200 http://youtu.be/DDttEAs8pZs (http://youtu.be/DDttEAs8pZs)
TORIOD FERRITE CORE 470 Khz TEST http://youtu.be/xNBsWEpcTDY (http://youtu.be/xNBsWEpcTDY)
He sure has a lot of toriod's to experiment with and it looks like he has also replaced the toriod's inside the SP200. Maybe he has changed it's operating frequncy:
http://youtu.be/wY8mSnWTlUc (http://youtu.be/wY8mSnWTlUc)
Hmm, from seeing these videos, i get the impression that he is somewhat blindly trying to get the STTC tips to work on the SP unit, while not really understanding how it works. Looks like a complete trial & error approach. The first video seems to show that the performance of the STTC connected to the SP unit is rather poor, and while he has lots of tips, many of them don't look healthy at all. Sure, i can only guess here, but by the looks of it it seems more that the tips are heated mainly through heating the coil.
The fact that a small area above the tip, where internally the copper slug, alloy and coil sits, is heavily blackened would indicate that. Usually the darkening of that area happens rather slow and is spread out a bit larger than that. I had that effect when i had a too high idle voltage on my DIY supply. It caused the tip to glow dark red at exactly that spot, meaning that the coil itself heats up while no longer inducing (much) energy into the alloy/slug but having mostly resistive losses.
But then, i don't understand what he says either, so this is just guesswork from what i can see combined with my own experience. In any case, kudos to him for being so persistant in trying it all out ;)
Greetings,
Chris
hi there Chris;
The names Chris; From the OZ.
Been keeping an eye on this discussion for a while now,
First of all i would like to say a big thanks for the research you have done and the time you have put in.
i've recently had the chance to use a thermaltronics iron and i've fallen in love with the inductive technology; the only thing keeping our love apart is the price ($550 in AU for the 13.56mhz machine), although i am now thinking about purchasing the original metcal tips if what you referred to in a previous post is true about efficiencies of the two manufactures tips.
With that being said;
Whenever you change something in regards to the schematic/adjust a value of a component, have you been updating your zip data with the changes?
I've read all 20 pages of this thread and you've made quite a few changes since your original files but shy of printing the 20 pages out and highlighting every change is there a way to get all the current files including eagle, girber, and parts list?
also, further to that point, if there is anybody here from Australia who has had these boards produced, and have some spare, if you could drop me a PM that would be appreciated.
regards. Christopher
as for the caps, the parts that i use are from RS-Online:
100n, 50V, X7R, 0805 264-4416
4µ7, 25V, 1206 723-6679
Besides those, in the power supply section i have:
100µ, 50V, Electrolytic 758-1272
10µ, 50V, X7R, 1210 723-6824
150µ, 16V, 716-7100
... although i am now thinking about purchasing the original metcal tips if what you referred to in a previous post is true about efficiencies of the two manufactures tips ...
hey Chris
let me be the first to say i would love a set of these boards, i was just about to get a couple made when i saw this post.
i also know a couple of people here who would get a set as well, depending on time frame.
i think the current board arrangement suits most well, that way people can choose weather they want the UC or not.
regards. Christopher
Hi Chris,
I would be interested in buying a PCB, but probably just the RF board. Any idea of the price per board?
I think the most useful option would be a board that has enough onboard to be useable standalone with maybe just a couple of LEDs as the user interface (maybe RGB), but that people can add their own add-on if they want anything clever like a display etc.
If it get done, you could add one or two unit for me in your batchI think the most useful option would be a board that has enough onboard to be useable standalone with maybe just a couple of LEDs as the user interface (maybe RGB), but that people can add their own add-on if they want anything clever like a display etc.
With the power supply section included, you mean? If so, that is basically what i had in mind. Make it a bit bigger to put the rectifier and voltage regulators there, so it can be used stand-alone, plus the header to connect to some more fancy stuff if one wants.
Greetings,
Chris
just to add something on the sub topic of making at portable. i was quite amused to find a low voltage mosfet that is quite fast, so i thought i have a go at it in a simulation (note its not accurate) (R9 = soldering iron load, i tried to measure its DC resistance, it was about 1.3ohms).
I've just repaired two MX500 power supplies (won at an eBay auction), with the help of the schematic and documentation here: https://www.mikrocontroller.net/attachment/193474/MX-500P-11.pdf (https://www.mikrocontroller.net/attachment/193474/MX-500P-11.pdf)P.S. Why you use IRF510?
It has a 0.5ohm internal resistance, may be something similar to IRFb4019 with 0.008ohm be more efficient?
P.P.S. Sorry, IRF630/IRF640/IRF740 i mean. Still, it is a UHF modulator ;)
Basically for two simple reasons:
- RF circuits are not really my field of expertise, so for the initial design i limited myself to the types that i had already used once in circuits operating at the same or higher frequencies, so i would know they should work in that application.
- Because i wanted to reduce the overall complexity of the circuit, i chose to use a readily available FET driver chip instead of the much more complex driver circuit used in the original Metcal supply. However, that chip is very tiny, and to avoid overheating i chose a FET with a really low gate charge and capacitance.
(Edit: Of course i might have been too paranoid with that. I just chose to stay on the safe side so i can get something to work correctly)
Of course that is not to say that only the IRF510 would work. But since i lack proper equipment to really evaluate other FET's, it would be up to others to see what else can be used there. The IRFB4019 that you mentioned looks interresting. It has even faster switching times, while still having a relatively low total gate charge. Might be worthwile to experiment with that one.
Greetings,
Chris
Found these old pics of a disassembled Metcal MX-RM3E https://imgur.com/a/RvDVu#0 (https://imgur.com/a/RvDVu#0)Isn't there a feed-through capacitor instead of a series capacitor as we talked about earlier from here onwards: https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg310381/#msg310381https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg310381/#msg310381 (https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg310381/#msg310381https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg310381/#msg310381)
From what my friend told me, there _seems_ to be none, according to the analyzer. Of course something could have gone wrong, and there is one and he just missed it, i don't know. After all, there is also the capacitance from the cable, so that any internal cap was simply "hidden" due to that.
Greetings,
Chris
Hi All,
Just wondering if anyone's still working on this? It's on my to-do list but other projects keep cropping up.
Hi There,Just curious who did your pcb manufacture with the matte black silkscreen and enig, they look beautiful!
I made a small batch of PCB's for this project.
I'll need only two of these, and since i won't be needing the spares i have, i tought of proposing them here.
I have 11 in Stock right now
Please don't hesitate to send me a PM if interested, as i really would like to get rid of these.
PCB Silkscreen for the RF generator (not the controller) has been moved in numbers since it was imported and assembled as a panel in Eagle (little mistake)
BUT BOM / Build instructions and Schematic were modified accordingly, so won't be a prob, i can email these to print for people that bought the boards of course.
it would be possible to include some of the hard to get bits, scroll down for Reichelt Shopping card,
link to the updated BOM sheet with manufacturers n°:
https://docs.google.com/spreadsheet/ccc?key=0Al25JwaqoqLrdENzU05vQlZHYThWemVJOHRIbU9Zamc&usp=sharing (https://docs.google.com/spreadsheet/ccc?key=0Al25JwaqoqLrdENzU05vQlZHYThWemVJOHRIbU9Zamc&usp=sharing)
PRICES: (again it's a non profit action, just adding numbers)
I'm making the PCB price incl. all, PPfees and Shipping worldwide (for sake of ease):
One PCB (Controller board + Generator) : 21Euros
Two PCB's (controller board + Generator) : 41Euros
for info:
PCB MFG Price: 16.5Euros
Shipping Worldwide: 2.8Euros to 5.75Euros (depending on quantity)
PPfees: +4% ( i make this one a little higher because Paypal can be off sometimes)
Depending on interest, "Hard to get Bits" prices will add up in a Group Buy manner etc...
It would be possible to add these kind of Small dissipators on the list too, but might check somewhere else to avoid LARGE Shipping time
http://www.ebay.com/itm/5pcs-13x13x11mm-High-Quality-Aluminum-Heat-Sink-For-Chip-Electronic-H36-/181109747336?pt=LH_DefaultDomain_0&hash=item2a2afb6e88 (http://www.ebay.com/itm/5pcs-13x13x11mm-High-Quality-Aluminum-Heat-Sink-For-Chip-Electronic-H36-/181109747336?pt=LH_DefaultDomain_0&hash=item2a2afb6e88)
For cutting them apart, you'll still need to cut, with a saw, some "plain" parts on each end before beeing able to break apart.
(http://s21.postimg.org/74krlc4wn/20140818_145246.jpg)
(http://s14.postimg.org/wb92393dd/Hard_to_get_bits_Reichelt.jpg)
It's a China based manufacturer, nice quality and good service.
But i've seen other manufacturers based in Asia having similar quality.
Now for double sided, and maybe a little more they sem to be good, can't tell
for any complex stuff tough.
http://www.pcbcart.com/ (http://www.pcbcart.com/)
I'm one of those two. If anyone's keen, but can't face the surface mount soldering, I'd be happy to run their boards through the machine as I do mine. No guarantees of quick turnaround, and I'd only do the surface mount. Proper lead-free solder & machine placement, though.
these are aftermarket boards that will work with original Metal handsets
I have an MX-500 that's had a few problems with the base unit in the past
And you would be able to send them on to me (at some future time - I'm in no rush) populated with the SMT parts and I'd source and add the through hole myself and take care of enclosure, etc?
If I got that right, and if your offer is still open, I'm in.
I'm not the one who was proposing the SMD soldering service, ask forum member Precipice about that.
won't be an exact replacement.
I'm not the one who was proposing the SMD soldering service, ask forum member Precipice about that.
Well i was going to conclude, but there are some people interested so still open until i get my numbers and all.
Are you in for one board? Please confirm, prices and infos are a little up.
Best,
T.
I'm not the one who was proposing the SMD soldering service, ask forum member Precipice about that.
Yeah, no problem. If you have your boards bundled with mine, I'll stuff them when I do mine, and bill you for the parts used and post them out. No idea how much they'll cost, but I'll not take the piss.
Steve
Will this power supply work with the Hakko FX100 inductive hand-piece? Its tips are priced more reasonably that Metcal (click on the Related Tabs in the link below).I wasn't even aware Hakko had started
http://www.hmcelectronics.com/product/Hakko/FX1001-52 (http://www.hmcelectronics.com/product/Hakko/FX1001-52)
(http://www.hmcelectronics.com/cat/images/FX1001-52_700.jpg)
Hakko’s FX-1001 soldering iron handle uses a standard RF connector to attach to the power supply and runs at 13.56 MHz, the same frequency that Metcal uses in their older MX-500 and newer MX-5000 series (it also fits into their stand). It will not work in the formerly branded OKi products as these use a lower frequency of 450 KHz. This means that with the purchase of the FX1001-51 for about $85, a user can switch over to the superior, affordable Hakko T31 tips and start saving money right away. Once the competitor’s power supply dies out, the Hakko FX100-04 power supply can be purchased to give a further performance improvement, including the Boost Mode.
I wasn't even aware Hakko had startedcloning Metcalmaking 13.56 MHz Curie Point Induction Soldering Systems.
Everybody has received their package safe and sound?
Also Thermaltronics (in Australia and USA) make induction soldering stations, and quite well priced replacement cartridges and tips / handles .Thermaltronics have already been mentioned and tested to work with this DIY supply earlier in this topic. Thermaltronics was founded by former Metcal employees once the Metcal patents expired.
http://www.thermaltronics.com/replacement_tips.php (http://www.thermaltronics.com/replacement_tips.php)
They are color coded into 600F 750F 800F , blue yellow red.
There is a keyhole shaped slot in their soldering stand so you can change tips/ cartridges while operating.
Basically any induction soldering iron that has a coaxial connector in the lead should work with the 13.56 system, It's usually a "F" connector = same as used on US television sets for the antenna.
Hello could somebody make a partslist for mauser or another store it would be nice if you could order a kit :) just an idea
Hello could somebody make a partslist for mauser or another store it would be nice if you could order a kit :) just an idea
There is a BOM on Reply #330 that was made for the Boards i had ordered, so you have parts refs there,
but unfortunatly the Silkscreen is different from original File of this one, Silkscreen is different for the RF Generator.
Alos all parts for building this one are not available from Mouser, you need some parts that can be found @ Reichelt,
if you haven't read the latest posts i made.
+ Not many are interested on this one, so not sure about a KIT.
Best,
T.
Hello could somebody make a partslist for mauser or another store it would be nice if you could order a kit :) just an idea
There is a BOM on Reply #330 that was made for the Boards i had ordered, so you have parts refs there,
but unfortunatly the Silkscreen is different from original File of this one, Silkscreen is different for the RF Generator.
Alos all parts for building this one are not available from Mouser, you need some parts that can be found @ Reichelt,
if you haven't read the latest posts i made.
+ Not many are interested on this one, so not sure about a KIT.
Best,
T.
You im back
so im only 15 but im on an electrotechnician school and so on i wouldn´t say people arent interested on a kit but they are to lazy to ask i was looking at parts on farnel and i wasn´t on the half and there were 200€ i mean if you could put the cost down get some boards a nice case and you could create a good brand the design is nice and mamalala had some work with it but deam if he could make a kit i think if he puted it on dangerous prototipes and the pcb on seedstudios he could make some money
i am interested in metcal irons becouse my curent is a tesla one an it works nice but you know you have to move on
so if we could put all the components in one place to sell it would be more then good and i think people would buy it when it hac a cost like a used metcal
guys it is nice what you do and you are great at it so i wana see some progres :)
greatings form slovakia
I've hit a problem in the area around IC7 - In the schematic and BOM R40 is listed as 22k, in the build guide it is 2k2, which is correct?
Also having gone through all the documentation again there is green comment text next to R41 saying "200R" despite this being a 1k. Whilst examining this it also occurred to me that the choice of R39 (the pot) or R54 and R55 (fixed divider) will make the circuit perform differently. With the fixed resistors R41 is effectively 1050 Ohms to 2.5V, with the pot fitted and in the middle R41 is effectively 3500 Ohms to 2.5V and, this being an inverting amplifier where the value of R41 matters, this has a direct effect on the gain. I have fitted R39.
I'm using zayance's board and the design pack he sent me.
1) In zayance's schematic there is, from transformer to output, 47nF x6 series, 22pF x2 shunt, 1uH series, 56pF x5 shunt, 1uH series, 56pF x3 shunt, 400nH series, 56pF x4 shunt. I've read various posts about missing out or fitting extra 56pF capacitors, is the above correct or should I add/remove some capacitors?
2) Is the firmware attached to post #204 the most recent available?
3) Have any binaries been posted or could someone send me one please? I will be using the PIC18F2620.
4) What's the optimum/min/max supply voltage? I've seen 24 mentioned as usable but low, and 26, 28 and 30V mentioned various times. I will probably build with a 50 Hz transformer but I'd like to pick the best secondary voltage.
I'll use your photos as a starting point and go from there. When I'm done I plan to post a log of tweaks and changes I made to get it going.
Whilst you could use the origonal gerbers I would suggest a few of changes:
1) Add in pads for the extra 56 pF capacitor.
2) Put some thermal relief in. I've found a lot of areas where something that carries no real current (d.c. or RF) like a logic pulldown is unsolderable with a small iron because one end is hard-down onto a large area of ground plane.
3) Consider swapping the LCD pinout to the standard one.
4) A little bit of BOM rationalisation would be nice. For example the Aux supply capacitor for the switcher (can't remember the number now) is currently the only 1206 10nF in the design and could have been the same as the 10nF 0805's scattered everywhere.
5) Depending on your skill with surface mount soldering the pads might benefit from tweaking slightly - they're perfect for reflow but a little tight for hand work.
Edit2: With a beefier PSU I can get to 21V on L2. At this point I have 62V peak RF into 50 Ohms (just shy of 40 Watts) and about 380 mV on VFB. I can hear a hissing sound but I'm not sure if it's from the buck converter or the RF transformer, maybe the control loop is unstable and oscillating at audio frequency? Thoughts?
A quick question - how is the encoder connected?
The software refers to the four inputs as A, B, K and S, the schematic as A, B, C, D, and as far as I can tell from the documentation the intention is to have an encoder with a built-in push button and use long and short pushes. To my mind that gives two inputs for the rotation, one for the button, one spare input and GND as the return for all four, is that correct? And if so which is which?
I have a few spare encoders but none with buttons and it sounds like a nice way of doing it. Any suggested part numbers?
Regards
Richard
Edit: A repeat of my question from #395, I think it got lost amongst the rest of the post. Are the nodes VREG and V+ on the RF board connected? Should they be?
I powered it up to test it after that and it still works though I noticed some odd behaviour. I am uncertain if it is new, I was cooling the tip much more than in previous tests because I wanted to check the output MOSFET didn't get too hot. The supply seems to work normally except that sometimes I can cool the tip heavily and the output power observed on the LCD does not seem to increase as would be expected, likewise the tip seems to cool rather too much.
For now only two folks interested, and 8 PCB's left.Hi
Anyone else?
Hi all,
a few notes and status updates here.
First of all, i noticed somethig weird regarding the power output. Either the supply voltage radings found in the MX500 document are wrong, or my circuit is way more efficient/better-tuned. If i set the idle voltage to around 18 volts, i get some of the tips glowing dark-red around where the coil is! That means way too much power is pumped into the cartridge for too long. Setting the idle voltage to around 12.5 to 13.5 volts, which is way lower than what can be found in the document, makes everything work nice again. Of course this value is for small/medium sized tips. Larger tips idle at a slightly higher voltage (13.5 to 14.5 volts).
Anyways, during heatup (or boosted power at wakeup) a supply of around 21.5 volts goves a nice, fast heatup time.
I also made slight modifications to some part values. The reason is that i am currently very busy working on the firmware, and thus found out a few things. Here are the changes:
- On the RF board, use a 100 Ohms resistor for R11 (this one involves the µC-controlled power limit/boost function)
- Again on the RF board, change R8/R9 to 4.7 Ohms. Those are the gate resistors of the IRF510.
- Still on the RF board, change R33/R34 to 100 ohms each. This provides a lower impedance of the VCC/2 voltage for the OpAmp in the control-loop.
- The last change on the RF board is to use 22 Kilo-Ohms for R23 and 1 Kilo-Ohm for R24. These are also for the control-loop OpAmp, setting a higher gain.
- On the controller board, the variable resistor to set the boost power should be 1 Kilo-Ohms, that way a nice adjustment is possible. The one for the limited power is 10 Kilo-Ohms.
The maximum supply voltage as given by adjusting R32 on the RF board should be around 21.5 volts (no boost/limit active, purely the control loop). Regarding the idle voltage fo the tips, here is a rough overview for some tips:
Between 12.5 and 13.5 volts_
STTC-147
STTC-126
STTC-037
STTC-025
Between 13.5 and 14.5 volts:
STTC-011
SMTC-147
As for the limited and boosted voltages, it turns out that in limit-mode a voltage of around 10 volts, and in boost mode a voltage of around 18 volts give good results. For example, adjusting with a STTC-147 tip would be done the following way:
- Insert the cold tip. Power up in normal mode and monitor the voltage. Adjust R32 so that it never exceeds 21.5 volts. If it does, let the tip cool down again and repeat this step.
- Once the tip reached temperature, adjust an idle voltage of about 13.5 volts using R19. Let the tip cool down and repeat the previous step. If required repeat these two steps as often as required to rech these values. Should be very easily done, however.
- Let the tip sit idle at normal power, that is, no limit or boost enabled, for about 10 minutes. Re-adjust R19 to give an idle voltage of around 13.3 volts. Let it sit that way for 10 more minutes, and if needed make slight adjustments to R19 to bring it back to 13.3 volts.
- Enable the power-limited mode. This is done by pulling the controlling microcontroller-pin to GND. That pin goes though an 1N4148 diode, then the 1k adjustable resistor, into the VLIM adjustment pin on the RF board, where it ends up at R11. The diode is connected with the cathode to the microcontroller pin and the anode to the adjustable resistor. Now adjust that 1k trimpot to give a supply voltage reading of between 10.0 and 10.2 volts.
- Now enable the power-boosted mode. This uses the same microcontroller pin, but this time pulled high to +5 volts. This signal now goes through another 1N4148 diode, then through the 10k trimpot, and again ends up at the VLIM pin of the RF board. This diode is connected with the anode at the microcontroller pin and the cathode at the adjustable resistor. Now set that 10k trimpot so that you get a supply voltage reading of roundabout 18 volts. When done switch back to normal mode...
This concludes the adjustments required to the circuit, and it should now be fully operational. The unit is now adjusted such that in normal mode the tip is kept hot and that load changes are quickly detectable. In normal mode the control loop will nicely adjust the supply voltage to keep the tip at the temperature. During limit-mode, which is very usefull to implement auto-sleep, any slight load change will cause a huge change in the available readings (forward-voltage, reflected-voltage, and subsequently the calculated SWR and power levels). Even pulling the handle out of the stand causes enough load change to give a huge delta-reading of the above values combined. Also, when waking up, the boost-mode now allows for a quicker recovery if needed.
I will explain how to use those values to detect changes, etc., in the next post later today explaining the firmware that i am working on.
Greetings,
Chris
Hi all,
just wanted to say, zayance sent me those PCB's and they look just great! Thanks very much for that, zayance!
If you plan to build one, go for it. Right now i'm rather busy with other stuff, plus i'm short on funny-money to spend on private projects right now, so the next version of the supply board will take some time.
Greetings,
Chris
Wait didn't you get the email i've sended with the files for it?
Meaning updated Schematic etc...
Basically it's exactlly the same latest board as mamalala only diff here is that there was a prob in the silk on the Generator side,
since i made one PCB to have both designs, Eagle pushed the Silkscreen numbers beside of just copy/pasting (logic and bummer).
I also moved the silk for some components here and there to make the assembly and it's visualisation easier, that's all.
So i made a Corrected BOM AND a corrected Schematic + Build doc according to the right Tname and values etc....
Something that i've sended to people who bought the boards, including you if my memory is not failing already??
Please let me know
I repeat, All the rest is the same :)
Best,
T.
Yea, all that stuff was left in that state while i was still experimenting with the performance of the unit. In the actual unit i have here, as well as the ones i gave away, i have (using zayance's part numbers):
R40 = 22k
R41 = 200R
R54 = 100R
R55 = 100R
R39 is not installed.
Sorry for the confusion.
Greetings,
Chris
1) In zayance's schematic there is, from transformer to output, 47nF x6 series, 22pF x2 shunt, 1uH series, 56pF x5 shunt, 1uH series, 56pF x3 shunt, 400nH series, 56pF x4 shunt. I've read various posts about missing out or fitting extra 56pF capacitors, is the above correct or should I add/remove some capacitors?
2) Is the firmware attached to post #204 the most recent available?
3) Have any binaries been posted or could someone send me one please? I will be using the PIC18F2620.
4) What's the optimum/min/max supply voltage? I've seen 24 mentioned as usable but low, and 26, 28 and 30V mentioned various times. I will probably build with a 50 Hz transformer but I'd like to pick the best secondary voltage.
Attached are three images from my rather dusty development unit that show how many caps i have installed. I did the same cap placement on subsequent units. Again, feel free to fiddle with that a bit, i went for "as much like a sine at the output as possible" plus "large Vpp output into a 50 ohms RF dummy load". Also again, it probably isn't perfect, and some room for improvement left in the filter section. Did you note the update to the coil winding scheme that happened later? Should be documented, if you can't find it i will make some pics of the current ones as well.
Also attached are two ZIP files, one containing only the compiled .cof and .hex files, the other contains the sources (the whole MPLab-X tree, in fact). The project compiles with Microchips C18 compiler.
About the voltage, 24 volts is enough to get it working well, i use an old 24V transformer from an old soldering station. Just don't go too high, the buck regulator can't take too much.
Greetings,
Chris
It's finished! Or very nearly anyway.
Since my last post I have modified the board with an undervoltage lockout circuit, mounted a boost converter module in the case for low-voltage d.c. input (10-30 V), and made up a small reverse polarity / overvoltage protection circuit for the new d.c. input, photos attached. Still to do is some input filtering on the DC lines, debugging the occasional odd behaviour seen previously and some general tidying up.
Edit: added schematics.
It's buried in post 184, I don't know if a build guide for the controller was ever written but if it is this should be in it. First of all setup the RF controller according to it's build guide (adjust R32 so the d.c. output buck converter is 22V while the RF output feeds a 50 Ohm dummy load. Then put a real tip in and make the adjustments described below. All voltages are measured at the output of the buck converter on the RF board, this is effectively the output mosfet drain voltage.
I've included the start of the post with component changes but if you are using recent documents those changes should already be in. I've highlighted the bit I think you need.Hi all,
a few notes and status updates here.
First of all, i noticed somethig weird regarding the power output. Either the supply voltage radings found in the MX500 document are wrong, or my circuit is way more efficient/better-tuned. If i set the idle voltage to around 18 volts, i get some of the tips glowing dark-red around where the coil is! That means way too much power is pumped into the cartridge for too long. Setting the idle voltage to around 12.5 to 13.5 volts, which is way lower than what can be found in the document, makes everything work nice again. Of course this value is for small/medium sized tips. Larger tips idle at a slightly higher voltage (13.5 to 14.5 volts).
Anyways, during heatup (or boosted power at wakeup) a supply of around 21.5 volts goves a nice, fast heatup time.
I also made slight modifications to some part values. The reason is that i am currently very busy working on the firmware, and thus found out a few things. Here are the changes:
- On the RF board, use a 100 Ohms resistor for R11 (this one involves the µC-controlled power limit/boost function)
- Again on the RF board, change R8/R9 to 4.7 Ohms. Those are the gate resistors of the IRF510.
- Still on the RF board, change R33/R34 to 100 ohms each. This provides a lower impedance of the VCC/2 voltage for the OpAmp in the control-loop.
- The last change on the RF board is to use 22 Kilo-Ohms for R23 and 1 Kilo-Ohm for R24. These are also for the control-loop OpAmp, setting a higher gain.
- On the controller board, the variable resistor to set the boost power should be 1 Kilo-Ohms, that way a nice adjustment is possible. The one for the limited power is 10 Kilo-Ohms.
The maximum supply voltage as given by adjusting R32 on the RF board should be around 21.5 volts (no boost/limit active, purely the control loop). Regarding the idle voltage fo the tips, here is a rough overview for some tips:
Between 12.5 and 13.5 volts_
STTC-147
STTC-126
STTC-037
STTC-025
Between 13.5 and 14.5 volts:
STTC-011
SMTC-147
As for the limited and boosted voltages, it turns out that in limit-mode a voltage of around 10 volts, and in boost mode a voltage of around 18 volts give good results. For example, adjusting with a STTC-147 tip would be done the following way:
- Insert the cold tip. Power up in normal mode and monitor the voltage. Adjust R32 so that it never exceeds 21.5 volts. If it does, let the tip cool down again and repeat this step.
- Once the tip reached temperature, adjust an idle voltage of about 13.5 volts using R19. Let the tip cool down and repeat the previous step. If required repeat these two steps as often as required to rech these values. Should be very easily done, however.
- Let the tip sit idle at normal power, that is, no limit or boost enabled, for about 10 minutes. Re-adjust R19 to give an idle voltage of around 13.3 volts. Let it sit that way for 10 more minutes, and if needed make slight adjustments to R19 to bring it back to 13.3 volts.
- Enable the power-limited mode. This is done by pulling the controlling microcontroller-pin to GND. That pin goes though an 1N4148 diode, then the 1k adjustable resistor, into the VLIM adjustment pin on the RF board, where it ends up at R11. The diode is connected with the cathode to the microcontroller pin and the anode to the adjustable resistor. Now adjust that 1k trimpot to give a supply voltage reading of between 10.0 and 10.2 volts.
- Now enable the power-boosted mode. This uses the same microcontroller pin, but this time pulled high to +5 volts. This signal now goes through another 1N4148 diode, then through the 10k trimpot, and again ends up at the VLIM pin of the RF board. This diode is connected with the anode at the microcontroller pin and the cathode at the adjustable resistor. Now set that 10k trimpot so that you get a supply voltage reading of roundabout 18 volts. When done switch back to normal mode...
This concludes the adjustments required to the circuit, and it should now be fully operational. The unit is now adjusted such that in normal mode the tip is kept hot and that load changes are quickly detectable. In normal mode the control loop will nicely adjust the supply voltage to keep the tip at the temperature. During limit-mode, which is very usefull to implement auto-sleep, any slight load change will cause a huge change in the available readings (forward-voltage, reflected-voltage, and subsequently the calculated SWR and power levels). Even pulling the handle out of the stand causes enough load change to give a huge delta-reading of the above values combined. Also, when waking up, the boost-mode now allows for a quicker recovery if needed.
I will explain how to use those values to detect changes, etc., in the next post later today explaining the firmware that i am working on.
Greetings,
Chris
For now only two folks interested, and 8 PCB's left.
Anyone else?
I would love to have the original design in some file format...For now only two folks interested, and 8 PCB's left.
Anyone else?
Is it still possible to order the PCBs? :) I wish to get it ::)
Just doing some tidying up - have come across the V0.2 bare PCB from mamalala and a bag containing quite a few of the parts.Why so much praying to PBS? Can someone publish a comprehensive message in the first part work a summary and crowdsourcing schematics and layout for at least kicad and Eagle?
I doubt I'll ever get round to doing anything with them so will post free to anyone in the UK that wants them.
If no takers in UK for a couple of days I'll send overseas for GBP5 via paypal to cover postage costs.
Why so much praying to PBS? Can someone publish a comprehensive message in the first part work a summary and crowdsourcing schematics and layout for at least kicad and Eagle?
cur_tip = tip_detect_get_status();
if(cur_tip != old_tip)
{
if(old_tip == TIP_MISSING)
{
power_manager_init_state();
infodisplay_reset();
if(power_manager_get_state() == PM_OFF)
{
power_manager_set_state(PM_HEATUP);
}
else if(power_manager_get_state() == PM_MANUAL_OFF)
{
power_manager_set_state(PM_MANUAL_NORMAL);
}
}
old_tip = cur_tip;
}
if(power_manager_get_state() != PM_OFF)
{
logger_print_params();
cur_tip = tip_detect_get_status();
if(cur_tip != old_tip)
{
if(old_tip == TIP_MISSING)
{
power_manager_init_state();
infodisplay_reset();
if(power_manager_get_state() == PM_OFF)
{
power_manager_set_state(PM_HEATUP);
}
else if(power_manager_get_state() == PM_MANUAL_OFF)
{
power_manager_set_state(PM_MANUAL_NORMAL);
}
}
else
rf_manager_set_mode(RF_POWER_OFF);
old_tip = cur_tip;
}
}void tip_detect_process(void)
{
// if(RFG_EN)
if(power_manager_get_state() != PM_OFF)
{
if(TIP_DET == 0)
{
tip_status = TIP_MISSING;
RFG_EN = 0;
}
else
{
tip_status = TIP_OK;
}
}
}
Guys i dont understood ,where is the stuff ?
source code and schematics ??
loool im here around 5 minutes and still don't found the stuff about this thread talking
:palm:
loool im here around 5 minutes and still don't found the stuff about this thread talking
:palm:
Guys i dont understood ,where is the stuff ?
source code and schematics ??
loool im here around 5 minutes and still don't found the stuff about this thread talking
:palm:
loool im here around 5 minutes and still don't found the stuff about this thread talking
:palm:
loool im here around 5 minutes and still don't found the stuff about this thread talking
:palm:
Oh no! Five whole minutes! No instant gratification, total failure!
If your attention span is that short, this project is really not for you.
And, is that base to cord connector totally proprietary?
And, is that base to cord connector totally proprietary?
You mean the bog standard F connector?
And, is that base to cord connector totally proprietary?
You mean the bog standard F connector?
Huh. Is it because mine looks weird due to the early version that has a locking ring that I never noticed that? I'm going to have to look more carefully when I get home.
https://www.linkedin.com/pulse/diy-project-my-workshop-soldering-station-valeriya-p- (https://www.linkedin.com/pulse/diy-project-my-workshop-soldering-station-valeriya-p-)
this woman has done the assembling of those 2 pcb's better and cleaner then most men's around here ... ::) ::) ::)
Anybody out here is thinking to re-design some part's of the pcb?(rf power supply)The link to the link to the image you posted doesn't work anymore. Looks like the direct link changes dynamically. Here's a new link:
I want to say that in the hakko fx100 we have the rf connector soldered directly in the part where the rf power output is.
In the diy metcal power supply we must to solder some kind of 75ohm of cable to make the connection over the iron handler and the power supply.
Is this a really good way to make less radio loss over the rf power connection?
because personally i think will be better to solder the connector directly on the pcb.
In this picture you can see what im talking about.
(http://s15.postimg.org/nxs6db9vt/hakko_fx_1000.png)
https://www.linkedin.com/pulse/diy-project-my-workshop-soldering-station-valeriya-p- (https://www.linkedin.com/pulse/diy-project-my-workshop-soldering-station-valeriya-p-)Looks like it forum member hhw (https://www.eevblog.com/forum/profile/?u=114430) who made a post earlier in this topic: https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg813905/#msg813905 (https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg813905/#msg813905)
this woman has done the assembling of those 2 pcb's better and cleaner then most men's around here ... ::) ::) ::)
maybe someone has spare boards?
Iwanushk is that you from dangerprototype which unisolder 5.2 project ?
LOOL
maybe someone has spare boards?
Iwanushk is that you from dangerprototype which unisolder 5.2 project ?
LOOL
Yes, that's me!
U r AWESOME :)
Do UniSolder by sparkybg supports RF soldering irons too?No.
I don't think that is likely to be a major problem. At these frequencies the odd impedance at the junction is only a very short length compared to the wavelength and it should really be fine. You could edit the files to add a connector footprint if you like but I am not convinced it will make a lot of difference.
Oki maybe you are right,but i still can't figure out why the iron hadler of that guy is getting so hot,it's obviuosly an issue ...
However if the DIY Metcal Station is abbandoned by the owner ,it's useless to waste the proper time here.
This makes me sad ,because i was in love with this project :-BROKE
1)To power up this thing can i use an already made power supply ? maybe one like this ?
idpromnut: You sure can!
2)Which power-trasformer i must to get ,something like this? output : 30vac and 80va ?
idpromnut: I run my MeltCal at about 24-30VDC @ about 2-3A.
3)In the original metcal the tip inside the hadler goes to sleep when the handler is inside the stand ,but here is the same as in the original metcal ?
idpromnut: yes, but the catch is that the "mechanism" is in the hand piece holder, and not strictly in the RF board. The holder has a magnet near where the tip rests, and this changes the impedance of the tip which I believe makes the tip reflect more RF back to the RF supply which the supply detects and the built in feedback loop reduces the RF power to the hand piece.
Yes, thank you.
I have just had a chat with him, and he has no more boards left. I have had a look through the more recent posts, and people don't appear to have made any in any significant quantity. I will have another look but, as I say, I would be happy to make a small run of boards/kits if people were interested.
Thanks
D
Can anyone help me to find some good chinese manufacturer of ceramic pcb ????
I want to order some ceramic pcb for the rf stage .
Example :
Can anyone help me to find some good chinese manufacturer of ceramic pcb ????
I want to order some ceramic pcb for the rf stage .
Example :
Uh.. why do you want a ceramic board for this?
Because i have already build my own unit ,but the problem in my case is the heat.
So i need an type of pcb which would be resistant to heat.
Because i have already build my own unit ,but the problem in my case is the heat.
So i need an type of pcb which would be resistant to heat.
Hello again to all.It is an "F" connector, most commonly used for 75 ohm TV antenna connections in North America.
In search of incredible, i return to identify a MX-RM3e or newer MX-H1-AV tip's plug.
May be anyone identify it?
I buy some SMB connector, and i was very close - but no, it is slightly different.
Outer diameter of SMB female socket is 3.7mm instead 4mm in Metcal's tips, and inner pin diameter is 0,5mm, instead 1mm in Metcal ;(
Hello again to all.It is an "F" connector, most commonly used for 75 ohm TV antenna connections in North America.
In search of incredible, i return to identify a MX-RM3e or newer MX-H1-AV tip's plug.
May be anyone identify it?
I buy some SMB connector, and i was very close - but no, it is slightly different.
Outer diameter of SMB female socket is 3.7mm instead 4mm in Metcal's tips, and inner pin diameter is 0,5mm, instead 1mm in Metcal ;(
Great, we are back. ;D
What's new, My RF-Borad is finely working, the problem seem to be the XFMR, chris send me one of his and all problems went away. He only explanation that I can find is that RS send me the wrong ones. I will test them both next week with a network analyser to see what's the diference. I will also test a few Metcal tips. ;)
Meanwhile I finished my controller board design placed an order at iTead, my board are already on there way to Portugal. :D
Paulo
Your undervoltage cutout seems to match my schematic, and I can confirm that a 2N7002 would be fine (or pretty much any other low power SMT MOSFET, it's not critical.
I don't remember the failure mechanism, but I remember several people reported blowing up the RF FETs, and Chris said cleanly shutting down the supply would always prevent it.
I'd love any input on the RF stage. I plan on checking output power and SWR at some stage but it seems from previous posts that the system was decently SWR matched when it was designed. The IRF510 seems to run hot too but I can't find anything in that range that works any better without going up to another design.My next move is probably going to be to see if I can design both the Arduino board with the same fix as the PIC board and give hobbyists an option between the two. To me, it seems like either processor works well and should have no bearing on the final product - but for experimentation sake and builders' preference I am hoping to update both.
In my personal opinion this seems to be pretty useless ,because i think the rf-stage has more priority for now.
For example :
You can check what you can tweak or optimize on the rf-stage to make it less hot,you can optimize swr parameters etc, etc, etc ..... so basically leave for now the work on mcu's to later :)
Just my personal opinion .
Datasheets for convinience:
IRF510: https://www.vishay.com/docs/91015/sihf510.pdf (https://www.vishay.com/docs/91015/sihf510.pdf)
IRF530: https://www.vishay.com/docs/91019/91019.pdf (https://www.vishay.com/docs/91019/91019.pdf)
I haven't looked properly but I notice that the IRF530 has 3x more gate charge and all the switching parameters are slower. This is expected given you get the improved thermal performance by having a bigger die. It may well be a suitable MOSFET but I wouldn't just throw it in without re-examining the gate drive and testing on a prototype. If you unintentionally slow the switching then you will increase dissipation and it may very well run hotter despite the factor of two in RthJC. Essentially the real figure to consider for thermal performance is the change in sum RthJC+Rthinterface+Rthheatsink which is around a change of 6.5 C/W to 5 C/W with the 100x100mm heatsink and a greased mica insulator. Don't pay too much attention to the headline power figures in the datasheet, they're not really representative of real-world use (as in you can't usually get anywhere close).
I suspect the MOSFET-killing on switch-off relates unintended linear operation dissipating hundreds of Watts for milliseconds and taking it outside it's safe operating area. That should be fixed by the undervoltage lockout circuit.
I personally wouldn't change it, mine seems pretty robust and thermal performance seems sufficient with the 100x100mm heatsink everyone else has used. During testing I had it running continuously into a 50 Ohm load (equivalent of a cold tip that never warms up) for about half an hour and the MOSFET was only warm - maybe 40-50C.
If you do want to change it the datasheets offer hints but as they're not really specified for use as an RF power amplifier you will probably have to do it by experiment. I would stay away from the IRF540, as a minimum you would need to seriously beef up the gate drive (9x more charge needed, so 9x the current to do it in the same time), but the rise and fall times might still catch you out. Paralleled smaller MOSFETs might be simpler.
All I can really say is that I use mine fairly regulary and I haven't blown it up yet. I haven't looked at the mosfet failure in detail and it's not happened to so I'm really just speculating about the cause. I have even misused it as a 13 MHz source for immunity testing with no harm done.
The only bug it has is sometimes the power metering seems off, reporting that it's finished heating before it really has, etc. It may be a software bug but probably I should find time to tweak the thresholds which Chris has made configurable from the UI before I complain about it.
What I haven't done is tried a wide selection of tips.
Just hope to this awesome broject be finalized as best as possible ,so everybody can use it without any fear and problems.
I live in italy and to buy an real brand new metcal station i need to spend over 799 euros,because of 22% of taxes :( .
and this is on the official webstore ,if i will go to another place the price will be higher .... so pleas shut down your ignorance.
Thanks
http://i.imgur.com/58zX3X8.png (http://i.imgur.com/58zX3X8.png)
And yet, they're actually only €560..
Or you could obtain a new Thermaltronics, for about €400, or a second hand Metcal, for as little as €150 with some patience..
And yet, they're actually only €560..
Or you could obtain a new Thermaltronics, for about €400, or a second hand Metcal, for as little as €150 with some patience..
That isn't the reason for this project or why Chris spent the time on the initial design and firmware.
For one, almost every Metcal I've seen that's "cheap" is beat to snot and/or needing repairs of its own. Currently the only fully reverse engineered model is the initial MX-500 which doesn't have MCU control or display - which this has.
Then, you come to this project. It's open-source, it works very well, and gives you the option of choosing whatever hand piece and tips you want to use that are RF induction. So you can choose Hakko, Metcal, Thermaltronics... etc.
The choice is yours in the end - but you came to the projects section to tell us that we are better off buying something used - not much in the spirit of projects.
Lol if you really think that also this package is really affordable ,then pls send me € 460,85 to my paypal and i will be happy :)
Now - let's get back on track about the project and not about the trolling of what's considered a useful project to someone or not. Again, you came to the project section to pretty much say "why bother?". Good for you. Point noted. Now we will continue with the project just like you can continue browsing other topics since this is your "sore spot".
Thank you for clarifying. My intention was not to attack just to defend open source hardware like all projects on this site. I work on closed source hardware for a living and spend my days trying to fix things that aren't supported anymore but also no schematics available or replacements are too expensive. Broadcasting equipment is planned to be obsolete quickly and leave engineers suffering. And that's my work. So these projects are a breath of fresh air and I am a strong supporter of open source.And yet, they're actually only €560..
Or you could obtain a new Thermaltronics, for about €400, or a second hand Metcal, for as little as €150 with some patience..
That isn't the reason for this project or why Chris spent the time on the initial design and firmware.
For one, almost every Metcal I've seen that's "cheap" is beat to snot and/or needing repairs of its own. Currently the only fully reverse engineered model is the initial MX-500 which doesn't have MCU control or display - which this has.
I'm aware of that, but I'm not attacking this project - only his whining about the price of buying one.QuoteThen, you come to this project. It's open-source, it works very well, and gives you the option of choosing whatever hand piece and tips you want to use that are RF induction. So you can choose Hakko, Metcal, Thermaltronics... etc.
Which are all interchangable on the existing stations anyway.QuoteThe choice is yours in the end - but you came to the projects section to tell us that we are better off buying something used - not much in the spirit of projects.
No, I came to counter the bold claim of a member who I'm pretty sure has been banned twice that it's impossible to get a Metcal for under €800.
I actually really like this project, and I'd love to see a nice, portable 12V version I could use on the move. Not here to knock, I've been watching this thread for a while now to see how it goes. You'll note that nowhere have I said it's a bad idea and that you should just buy a second hand one - I simply said that you don't have to pay that much for a new station, let alone a used one.
ps. my Metcal predates the 'initial' MX-500 by over a decade and it's not the first model - it cost about $100 and had no damage but some corrosion on the stand - add in a transformer for a proper supply voltage (off the shelf part still!) and some tips, and I have a very nice station (which needs no display or MCU - not that those are bad). I just had to make room in the suitcase..Lol if you really think that also this package is really affordable ,then pls send me € 460,85 to my paypal and i will be happy :)
I think considering you get the power supply, iron, and stand, it's not an awful price for a brand new, warrantied product. I also think it's less than the €799+ you claim you must pay to get a Metcal.QuoteNow - let's get back on track about the project and not about the trolling of what's considered a useful project to someone or not. Again, you came to the project section to pretty much say "why bother?". Good for you. Point noted. Now we will continue with the project just like you can continue browsing other topics since this is your "sore spot".
Stop putting words in my mouth, please. Again, like this project, watching closely.
Just another day getting ready to use one here lol
No, I came to counter the bold claim of a member who I'm pretty sure has been banned twice that it's impossible to get a Metcal for under €800.Are you just pretty sure or you have some kind of proof ?
And yes ,here in Italy it's impossible to get a Metcal for under €800
Just another day getting ready to use one here lol
Are the strain reliefs on the handpieces still taking a 'set' from sitting like that? Mine's never coming out.. but it's been in there for 20 years.No, I came to counter the bold claim of a member who I'm pretty sure has been banned twice that it's impossible to get a Metcal for under €800.Are you just pretty sure or you have some kind of proof ?
Nope! Not that it matters to you:QuoteAnd yes ,here in Italy it's impossible to get a Metcal for under €800
As I proved that it is possible, and you ignored it.
You are such a dumb-ass,you didn't yet realize that also 400,00 euros are very expensive here in Italy .....
Also if i could get an complete metcal system (1tip,handpiece,stand,power supply) for 600,00 euros it would be always too much expensive with the average salary of 1200.00 shekels................. think about that Monkeh.
someone can explain me pls ,why i can't find the new pcb gerber from mr. NavyBOFH ?
Curious: How much do we know about how the soldering tips are designed?
How feasable would it be to make your own soldering tip from scratch.
Ignore the cost factor etc. Say this is for a different application no standard tip would do?
Since the ordinary transistors like the IRF510 can't solve the common problems of this RF power supply,then,can we go with an dedicated Rf Fet like this?
Since the ordinary transistors like the IRF510 can't solve the common problems of this RF power supply,then,can we go with an dedicated Rf Fet like this?RF fets usually have low Vds voltage, SD1902 has 65V only. It is too low for this application. I would recommend you to completely redesign output schematics to make two-stage output amplifier, as it was made in the original Metcal stations. They use such solution to avoid Vds overstress. For example, in the new MX5000 output transistor has 500V Vds! But of course it has very large input capacitance, so it can't be driven directly at 13,6 MHz by the tiny standard driver.
SD1902
Mr.NavyBOFH,is also out from this project,he promised pcb gerber files ,but none yet....... :--
Im selling my old Metcal Diy Pcb's board if you are interested ,then please write me in private :)
Thanks you very much.
Привет! HI , Ciao ! )Huge thanks to Christian for project!! HUGE!!Привет JustNote
I bought PCB and started to do.
Thanks again from Belarus. )
This is what I have come up with so far: I have zipped each functional section into its own ZIP. One is the RF board, which seems to be the latest as of June 2013. The BOM is from zoltan and seems to be what Chris references as the "best list" available.
https://drive.google.com/open?id=0B9MnfIuHNf_lNFlZaEwzbXdwOGc
@hww How much did it cost you? If you can be detailed that'd be great! Also, How did you build it? any guides?
What is the difference of this DIY with all the products listed here:
[Sorry if the questions are dumb!]
Have you managed to keep EMI at a reasonable level?
That would be one of my main concerns here.
Could somebody offer me a more human understandable description about them? Like the material of the core - and how could they be replaced with other types if possible - salvaged from other SMPSs?
Could somebody offer me a more human understandable description about them? Like the material of the core - and how could they be replaced with other types if possible - salvaged from other SMPSs?
The thread is long, though there have been various attempts to group the information. I would recommend using the cores specified and then it's just a matter of winding the right number of turns. From memory I think the winding instructions were in one of the word documents describing the assembly process. If you want to change cores then you need to know much more what you're doing, but if you must change to due limited availability then I would strongly recommend purchasing cores with a known specification. Working with salvaged cores is a problem because you don't know the material characteristics and you end up having to make a number of measurements on each core before you can decide if it's likely suitable or not.
I haven't had time to read this entire thread but: I'm curious why people have been waiting to pool PCB orders. Is this not a design you could simply send to OSH park to get built? Does it require something more advanced than what standard PCB manufacturers tend to provide?No particular reason or PCB complexity, it's just still cheaper per-board to pool orders, though perhaps not as much now as in 2012.
I'm reading the only schematic PDF of the RF board I could find, and I'm curious if there has been an updated one (this one is dated 2012) and also to some extent how it works. Sergey's design uses a current transformer and something like a ring mixer to generate a feedback signal to the DC-DC that depends on both the magnitude of the output voltage and the phase between voltage and current.The 2012 one is current, there have been a couple of mods (e.g. my undervoltage lockout circuit) but the 2012 schematic essentially works. Mamalala's design regulates for peak voltage at a filter node, which to my understanding corresponds approximately to constant-RF-current. Temperature regulation is then by the varying power absorption form the tip reaching an equilibrium temperature very close to the Curie point. The official Metcal ones also use constant RF current but the feedback approach is different. Sergey's design works in a more complex way - by regulating for 45 degrees phase angle he is essentially servoing the tip to a particular temperature. In principle this could give tighter temperature control but I suspect it does not make any significant difference in practice as the transition is very sharp.
This one appears to purely use the magnitude of a voltage sampled just before the last filter stage. I'm kind of a novice when it comes to RF so I'm wondering if the two are basically equivalent or if there are advantages.
And then I also wonder if the SWR bridge is just for testing purposes? what I read is that the RF board can function just fine without it.The controller board makes use of it for "smart features", primarily:
I have also been working on a test load that can be used in place of a soldering iron tip to stress test or tune either power supply:I did all my testing with a similar-looking load, but without reactive components.
Mamalala's design regulates for peak voltage at a filter node, which to my understanding corresponds approximately to constant-RF-current. Temperature regulation is then by the varying power absorption form the tip reaching an equilibrium temperature very close to the Curie point. The official Metcal ones also use constant RF current but the feedback approach is different. Sergey's design works in a more complex way - by regulating for 45 degrees phase angle he is essentially servoing the tip to a particular temperature. In principle this could give tighter temperature control but I suspect it does not make any significant difference in practice as the transition is very sharp.
For anyone who wants to use OSH Park to buy these: They don't like the gerbers, but they will take the .brd just fine.
Huh? No way, I've always sent Gerbers to OSHPark and gotten beautiful results. If they are rejecting your Gerbers, then you're violating a design rule or the file format is wrong.I'm using the google drive link posted earlier in this thread. When I got Sergey's board made I used his gerbers and they worked fine. With the ones posted earlier in this thread (only two search results for "gerber") it complains it can't find a board outline or drill file. The previews from the .brd look ok though.
Also, I was reading mike's comment to use the -ADJ version of the buck regulator, should I actually be using the -5 version instead? The datasheet says either can be used for voltages >5VI am assuming you mean the buck on the RF board, checking my Farnell order history I used LM22676TJE-ADJ
I've never measured efficiency or input power on mine. Out of interest how are you measuring output power? Into a fixed 50R load?
Edit: I found the peak detect output here to be not as linear as I'd hoped. I got the diode wrong in the schematic--I was actually using 1N914, not 1N4148. I modified it to use three 1N914s in series which gives me an output that's much easier to translate to the true peak. Also, the capacitor is 100nF X7R with a 33nF C0G in parallel, and the discharge resistor is 1M
Here's a rough schematic for the test circuit. I'm not sure about the discharge resistor and cap values on the peak detect circuit, but it's a fairly standard circuit and you can probably re-derive them
The 80W design (Sergey's) seems like it might be the best DIY choice if it could be revised to take universal mains and easier to source parts.
On the downside, the range of tips that are available is very small.I think all of the non-MX500 compatible products suffer from the same problem: The market share the MX500 family has is largely full of people that don't really want anything different, and the plentiful second-hand market means that new units from their budget line compete with old units from their flagship line.
mamalala design could be improved by simply adding pre-amp stage (as in Sergey design) which will solve the driver overload issue and will raise output power.I don't know about that. Sergey's design uses a power transistor (STP19NF20) with 3x current rating and 1/3 Rds(on), but also 3x gate charge, and that is what necessitates the preamp stage. The IRFP540 design you mention uses a gate driving transformer because the IRFP540 has even higher gate charge than that (150 nC vs 8 for the IRF540 and 24 for the STP19NF20).
Another aspect is the output transistor blow-up at the power-off time, which is a well-known phenomenon in high power RF amplifiers, that is the energy accumulated in the output filter which applies to the closed transistor and is well higher than its drain breakout voltage. In sergey design a TVS is used which is OK at this relatively low frequency, but a better solution is simple to use a transistor with a higher breakout drain voltage.Sergey mentions that the Metcal design does use such a transistor, but he used the TVS to allow for easier part selection.
One common technics used in industry is to taper drive oscillator signal down before switching it off, which means implementing soft power off in firmware. Here same might be done by driving down the output stage power supply.The bigger concern is not when the transistor turns off, but when the load is disconnected, as we don't know when that is going to happen.
I don't know about that. Sergey's design uses a power transistor (STP19NF20) with 3x current rating and 1/3 Rds(on), but also 3x gate charge, and that is what necessitates the preamp stage.Using 3x more current rating transistor sure would require more input power as usually gate input capacitance will increase, but my point was about possible improvement based on what I read about problems with that design.
Sergey mentions that the Metcal design does use such a transistor, but he used the TVS to allow for easier part selection.yes, as I mentioned, using TVS for this frequency is ok, and it is not a linear amp that would have totally different requirements to its output. But in mamalala design used transistor is quite at the low end with its 100V drain voltage...
The bigger concern is not when the transistor turns off, but when the output is disconnected, as we don't know when that is going to happen.Right, in this case, the whole power would be reflected, but for this, we have a feedback loop controlling DC supply... however I admit it might not be that quick, and combined with low-grade transistor the result is as is...
yes, as I mentioned, using TVS for this frequency is ok, and it is not a linear amp that would have totally different requirements to its output. But in mamalala design used transistor is quite at the low end with its 100V drain voltage...I'm not sure what voltage the transistor in the mamalala design sees as it's not connected the same way as in Sergey's design. Sergey's design is basically class C. Mamalala's design might also be class C (could be A?) but it's transformer-coupled, so I don't know if reflected power hits the drain of the transistor the same way. (I'm an RF noob)
Respecting one of the PDFs you linked: Going by their gate voltage graph they have something that looks vaguely like a ~12V amplitude sinusoid on the gate. With the gate capacitance of 2.6nF, that means the current waveform in and out of the gate is 1.6A RMS, so that's roughly 20 VA of reactive power just to drive the transistor. Doable of course but has to be kept in mind.That is one more point for pre-amp use, final stage gain is not that much and usually require substantial power to drive them...
I'm not sure what voltage the transistor in the mamalala design sees as it's not connected the same way as in Sergey's design. Sergey's design is basically class C. Mamalala's design might also be class C (could be A?) but it's transformer-coupled, so I don't know if reflected power hits the drain of the transistor the same way. (I'm an RF noob)it also looks to be class C as no bias network, and it is 1:1 transformer, then final amplitude depends on how well the output network is matched...
Ocela over at vrtp.ru successfully transplanted the RF feedback from Sergey's design into the
Mamalala board (can see via google translate) -
https://vrtp.ru/index.php?showtopic=30618&st=300 (https://vrtp.ru/index.php?showtopic=30618&st=300)
Mamalala reviewed some of his design choices and scope for improvement here, including converting
from a single driver to a push pull design -
https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg1467251/#msg1467251 (https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/msg1467251/#msg1467251)
This one below looks good - for the output filter, the 20m band values in the first link are quite close -
http://pa-11019.blogspot.com/2016/11/diy-kits-70w-ssb-linear-hf-power.html (http://pa-11019.blogspot.com/2016/11/diy-kits-70w-ssb-linear-hf-power.html)
http://wa5bdu.blogspot.com/2019/03/70-w-ebay-mosfet-hf-amplifier.html (http://wa5bdu.blogspot.com/2019/03/70-w-ebay-mosfet-hf-amplifier.html)
If you want to try hacking a buck converter module to add feedback, maybe start with this. Based around LM25116, less than $10. https://www.aliexpress.com/item/32845237362.html (https://www.aliexpress.com/item/32845237362.html)
Regarding LM25116, it looks to be no different from any other converters as feedback pin is available, do I miss something over here?
The chip I think would be suitable, I'm just not sure if the feedback pin is easy to access on the module that I linked to.
Can anyone give me a link for a soldering iron connector?If you mean the connector that the metcal handpiece connects to, it's just a normal type F coax connector.
Or his model. For example on ebay.
You also probably want one that has good length on it so it's easier to be sure the handpiece connector is fully seated. Note: It took me a while to learn how to best connect the handpiece connector, as it's kind of weird: You want to unscrew the collar on the connector all the way, then push it down over the jack as far as it will go, then spin the collar down and tighten it by turning the collar clockwise and the *cable* counterclockwise. You are not screwing onto the jack.
Another aspect is the output transistor blow-up at the power-off time, which is a well-known phenomenon in high power RF amplifiersThe blow-up at switch off can be fixed with a trivial circuit mod that disables the device if the input voltage is low. I added very crude circuit with Zener-based thresholding to mine which acted on the tip detect line to force a disable. Other more elegant ways are possible.
Ocela over at vrtp.ru successfully transplanted the RF feedback from Sergey's design into theThat looks interesting. :)
Mamalala board (can see via google translate) -
These are the instructions which are bundled with a Metcal handpiece -Ah, right, it comes with instructions |O
(https://www.jensentools.com/images/p/406-022.02_s500_p1._v3070c22a_.jpg)
On the downside, the range of tips that are available is very small.
It's very hard to find side by side comparison of the size of the handpieces. This makes me suspect that the 470K handpieces are significantly thicker, as the cartridges certainly are (going by the diameter of the cartridge compared to the tip).