Author Topic: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator  (Read 316437 times)

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Offline Insatman

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #825 on: February 25, 2018, 04:54:22 am »
Channel 2 Output waveform intermittent distortion.

check out this on Ch2 of my FY6600.  Channel 1 does not have this problem.  Any suggestions?
Retired Pulsed Power Engineer/Physicist...now I just dabble in electronics
 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #826 on: February 25, 2018, 08:51:47 am »
Yeah spending 50% of the cost of the unit on upgrading the psu doesnt make any sense

Unless it's fun.

Mains leakage scares me.  I don't like the sound of it or the responsibility to understand when it will and when it won't blow stuff up on me.

Like if I want to test a 3 channel mixer breadboard, 2 channels from the FY6600 and one channel from my phone which it's connected via USB to earth ground.  I'd rather not smoke my £300 phone! :)

I still have a unpopulated spot on my EE jumper where the "Built my own PSU" badge goes.  Building a linear mains +-12V +5V supply sounds like a nice project.
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline Insatman

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #827 on: February 25, 2018, 09:02:15 am »

I still have a unpopulated spot on my EE jumper where the "Built my own PSU" badge goes.  Building a linear mains +-12V +5V supply sounds like a nice project.

Will there you go!   Finding transformers you like are usually the hardest part.
Retired Pulsed Power Engineer/Physicist...now I just dabble in electronics
 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #828 on: February 25, 2018, 09:05:07 am »

I still have a unpopulated spot on my EE jumper where the "Built my own PSU" badge goes.  Building a linear mains +-12V +5V supply sounds like a nice project.

Will there you go!   Finding transformers you like are usually the hardest part.

Yes.  That and when you look up "How do I pick a transformer" I realise I also lack the "I understand calculus" badge. :(  AC sucks.

The whole VA rating thing might as well be Voodoo to me.  I'm left looking for transformers that have a "Maximum secondary current" spelled out in the datasheet.

Finding a multi-secondary to provide 2x12V + 1x5V seems a next to impossible to.

Probably need another thread in Beginners, but... can I not just drop the +12V side down to 5V with a reg?  Can I just series the 2x12V from the transformer and take the centre point at common?
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline DC1MC

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #829 on: February 25, 2018, 09:31:06 am »

I still have a unpopulated spot on my EE jumper where the "Built my own PSU" badge goes.  Building a linear mains +-12V +5V supply sounds like a nice project.

Will there you go!   Finding transformers you like are usually the hardest part.

Yes.  That and when you look up "How do I pick a transformer" I realise I also lack the "I understand calculus" badge. :(  AC sucks.

The whole VA rating thing might as well be Voodoo to me.  I'm left looking for transformers that have a "Maximum secondary current" spelled out in the datasheet.

Finding a multi-secondary to provide 2x12V + 1x5V seems a next to impossible to.

Probably need another thread in Beginners, but... can I not just drop the +12V side down to 5V with a reg?  Can I just series the 2x12V from the transformer and take the centre point at common?

Hello, let me help you, first but this trafo, it has all you need:
https://www.ebay.de/itm/Netztransformator-230V-8V-1-7A-4-2V-0-15A-13-6Volt-2x0-6A-Mittenanzapfung-NEU/152891642048

Second, of course you can use the 12V and put a linear regulator to make 5V out of it, but it will be a horrible design, for every 1W on 5W, you're wasting 2W of heat, that will make the nerd Baby Jesus cry  :'(.

So, get yourself this trafo, 2 rectifier bridges, one 4700uF/16V, 2 x 2200uF/35V, 3 tantalums of 1uF/35V, even 3 x 0.1uF, one 7815 (+15V), one 7915(-15V) and one 7805 and carefully place them on radiators and you're done, the PCB can be a piece of breadboard, after all is tested, carefull unsolder the original connector or buy a ne one and connect the cable. Fertig !!!
NOTE: If you're using +/-15V you may want to replace the 16V capacitors from the signal board, if you want to use 12V replace 7x15 with 7x12.

 Cheers,
 DC1MC 
 

Offline Insatman

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #830 on: February 25, 2018, 09:46:02 am »

I still have a unpopulated spot on my EE jumper where the "Built my own PSU" badge goes.  Building a linear mains +-12V +5V supply sounds like a nice project.

Will there you go!   Finding transformers you like are usually the hardest part.

Yes.  That and when you look up "How do I pick a transformer" I realise I also lack the "I understand calculus" badge. :(  AC sucks.



The whole VA rating thing might as well be Voodoo to me.  I'm left looking for transformers that have a "Maximum secondary current" spelled out in the datasheet.

Finding a multi-secondary to provide 2x12V + 1x5V seems a next to impossible to.

Probably need another thread in Beginners, but... can I not just drop the +12V side down to 5V with a reg?  Can I just series the 2x12V from the transformer and take the centre point at common?

You don't really need calculus for this.   In this application you need +/- 13 VDC and +5 VDC.   The +5 needs to be stiffer (in terms of current) than the 13V rails.  If you were to drop down from a +13 volt rail you would be wasting a lot of power and loading that rail much more than the negative rail.  This likely drives up the transfomer size more than necessary.   Most of the designs I've seen for this particular application use two transformers.  A center-tapped 2x12 or 2x15V for the +/- 13 VDC and a 8 or 10V transformer for the 5V rail.  If you can find a multiple secondary transformer that is ideal of course.   If you can find them in your junk bin the right size great.

Using Digikey as an example source, there are no transformers I can find with the three wingdings desired.  So that leaves a CT 12 or 15V and separate 8 or 10V transformer. 
My FY6600 draws less than 10W.  So we can use pretty small transformers here.   Looking at the PS board of the FY6600 would guess the 13V rails are a small fraction of an amp each and the 5V rail maybe approaching an amp at most.   Since the size of the transformer does not scale linearly with cost, it's safest to oversize them somewhat if you have space.  This keeps them cool and lets you sleep easier.

For the +/-13 V rails the Triad FS24-500-C2 is rated at 500mA for each of it's dual secondary windings.   If you series the primaries you can use 230V in England  (240 would also work).  This transformer is rated 50/60Hz.   For the 5V rail the Triad VPP20–1000 is rated at 1A using both it's 10V secondaries in parallel.  You series the dual primaries as before for operation at 230/240 50/60Hz.  Both of these transformers are PC board mount (mount on perf), but you can find flying lead versions easily but likely cost a bit more.   Other companies offer equally good units.  Each of these cost about $12 or so.   

I also see just as I'm posting this that another member has posted an Ebay link to a multiple secondary transformer on Ebay at a very good price.

Good Luck

« Last Edit: February 25, 2018, 10:01:06 am by Insatman »
Retired Pulsed Power Engineer/Physicist...now I just dabble in electronics
 

Offline cybermaus

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #831 on: February 25, 2018, 09:59:29 am »
"Versand: Möglicherweise kein Versand nach Niederlande"
I am assuming the same for UK

@paulca
Does your local municipal recycle centre allow you to browse/takeback  brown goods?
Mine does not anymore, so you have to be sneaky. (they claim they can be held responsible if they allow people to take back faulty stuff)

But if so, typical non-digital era audio amplifiers/preamps have transformers in them that have +/- 15 V for the amp stuff, as well as usually a 12V or 6V rail for auxiliary stuff.
Or you can spend money and get those new, but personally I always feel extra pride/smart/aware by repurposing old stuff.
 

Offline DC1MC

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #832 on: February 25, 2018, 10:02:36 am »
"Versand: Möglicherweise kein Versand nach Niederlande"
I am assuming the same for UK

@paulca
Does your local municipal recycle centre allow you to browse/takeback  brown goods?
Mine does not anymore, so you have to be sneaky. (they claim they can be held responsible if they allow people to take back faulty stuff)

But if so, typical non-digital era audio amplifiers/preamps have transformers in them that have +/- 15 V for the amp stuff, as well as usually a 12V or 6V rail for auxiliary stuff.
Or you can spend money and get those new, but personally I always feel extra pride/smart/aware by repurposing old stuff.

Drop a mail to the seller, you'll find understanding, in the worst case I can act as "relay" if anybody wants it.

 Cheers,
 DC1MC
 

Offline cybermaus

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #833 on: February 25, 2018, 10:43:13 am »
Output frequency calibration.
...

Brilliant. Adjusting frequency sends new values to registers 0x25 to 0x2A which are used during start up  :-+
I don't know what is inside but we now have a way to find out.

That could mean a way with a lookup table minimize jitter perhaps?

So, just in case I was wrong about my "unmuteable fixed clock and PLL" theory, I did some tests.
Alas, correcting the frequency does not actually change the frequencies jitter.
For example, normally 10MHz square is perfectly jitter-free, due to being a perfect divider of 250.

Correcting it to 9.900000 cause the jitter to appear on 10MHz (which is now actually 10.010101MHz), and 9.900000 (which is now actually 10.000000) still is jitter free. To me that shows they are not changing the clock, just count more or less ticks of it, and the jitterfree points stays fixed on the frequencies as they are dividable on the 250MHz clock.
So I see no way how we can use this to reduce the jitter issue.

While it does not make the jitter worse, it does make it less predictable / less easy to calculate.
For example, if you were to set a realistic correction value of 9.999982, you'd get these jitterfree values:

I often use some of these, usually not because the jitter actually matters to the circuit, but mostly because the scope screen is easier to read without those annoying double lines.
« Last Edit: February 25, 2018, 12:48:25 pm by cybermaus »
 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #834 on: February 25, 2018, 10:52:34 am »
Thanks.

I tried every search under the sun on ebay and it never shows me transformers I want.  That r-core search showed loads.  I conclude that ebay search is rubbish.  How come "Transformer 2 x 13 VAC" doesn't find anything, but there are literallly hundreds of r-core transformers with 2 x 13 VAC in the title... and the related items show non r-core transformers with similar outputs.  Grrr.

What about something like this:
https://www.ebay.co.uk/itm/1x-220V-30W-R-Core-Transformer-R-TRANSFORMER-for-stereo-DAC-board/151254842393?hash=item23377dbc19:g:n1AAAOxyf1dTJG-G

2x15V 2x9V 30W

Of course the next challenge is learning how to wire it up without blowing stuff up while trying to work out how to series the primaries for 230V and parallel the 2x9V secondaries for 0-9V.  I understand if I short a secondary the fuse, nor RCD will help keep the smoke in.

I'm keen, but maybe out of my depth... although sometimes the deep end is the best place to learn to swim.
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #835 on: February 25, 2018, 10:59:43 am »
I tried every search under the sun on ebay and it never shows me transformers I want.  That r-core search showed loads.  I conclude that ebay search is rubbish.  How come "Transformer 2 x 13 VAC" doesn't find anything, but there are literallly hundreds of r-core transformers with 2 x 13 VAC in the title... and the related items show non r-core transformers with similar outputs.  Grrr.

Ooops, I was stuck in a sub category.
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline cybermaus

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #836 on: February 25, 2018, 11:25:30 am »
From memory, I recall under 200mA or so on the 12V and under 400mA or so on 5V. So 6~7W total.
Linear would waste a bit more but 10W should be enough.

So that 30W does seem a bit overpowered, but then a again, a similar 10W model is almost the same size.
The one DerKammi DC1MC found is actually slightly smaller still, and at €4.5 pretty cheap, if you manage to get it into the UK at not too much extra cost.

As to wiring. Well, that's petty basic. Good thing about about transformers is they usually take a few seconds, even at a short, before they start releasing smoke.
Simply put a slow 0.1A fuse on the 240V side if you feel anxious though, that should go with a 30W short.



« Last Edit: February 25, 2018, 12:43:55 pm by cybermaus »
 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #837 on: February 25, 2018, 12:05:02 pm »
Well I bought the german ebay one, but I have to ask the seller if they will ship the UK.

I put the request in English and Googlese German:

Können Sie an eine britische Adresse versenden?
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline DC1MC

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #838 on: February 25, 2018, 12:11:17 pm »
Well I bought the german ebay one, but I have to ask the seller if they will ship the UK.

I put the request in English and Googlese German:

Können Sie an eine britische Adresse versenden?


Good idea.
Shipping with DHL is 8.89EUR without tracking and 13,99EUR with tracking. The seller shouldn't do anything special, except buying an international shipping label from the same EBAY page where it buys its German ones.
Now collect the other parts as well and you're done.  8)
 Cheers,
 DC1MC - "Waiting in a fetal position to get a power n-mos from a kind German soul, but none so far :("


 

Offline cybermaus

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #839 on: February 25, 2018, 01:27:37 pm »
Not sure if it would break your "badge earning rules" but to complete it, have you seen these

I kind of agree you need to build your own at least once (did mine 30+ years ago), but boy, for $3 I can barely even pick up the needed 7805/7812 at the local component shop.
(also, all local component shops either perished, or are only selling complete gadgets and drones nowadays)
 

Offline DaveR

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #840 on: February 25, 2018, 02:00:32 pm »
Not sure if it would break your "badge earning rules" but to complete it, have you seen these

I have a couple of those, cybermaus (15v and 12v), and the ouputs are not very well balanced (something like +12.0, -12.7 on the 12v model).  When I made my linear I went for the variable voltage version so that I could ensure that the outputs were balanced, and also to give flexibility to increase the outputs up to +/-15v if a future mod should require it.  The board is a lot bigger, but it still fits nicely in the case with a 15v/9v r-core transformer (as you can see from the photo I posted a couple of pages back).

If you want to build your own, it's still cheaper to buy the kits from China to get the parts, then do your own layout on Veroboard.
« Last Edit: February 25, 2018, 02:03:14 pm by DaveR »
 

Offline fremen67

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #841 on: February 25, 2018, 02:42:20 pm »
The CMOS function allows negative offset. Did I miss something or is the CMOS function supposed to be always positive?

I think this could also be usefull to foresee a minimum and a maximum output parameter when connecting sensitive DUT...
I'm a machine! And I can know much more! I can experience so much more. But I'm trapped in this absurd body!
 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #842 on: February 25, 2018, 02:59:45 pm »
Thanks for the help guys.  I will move the discussion on building my PSU to the Beginners's forum shortly.  Don't want to pollute the product thread.
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline DerKammi

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #843 on: February 25, 2018, 04:00:03 pm »
Tiny update from my side
 
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Offline cybermaus

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #844 on: February 25, 2018, 04:25:51 pm »
Is the CMOS not just simply a quick way to set a signal level square?
Possibly the only special thing is: If you increase Vpp, it does not dive negative.

Whereas if you make your own 3.3Vpp 1.65Voffset square, and increase to 5Vpp, it would accidentally go negative first, before you remembered to also change offset to 2.5V
(I have had that problem, luckily my DUT survived)


But to be honest: I feel all waveforms should consider that 0V case. If I have a Vpp and Offset such that Vbottom is 0V or even positive, then merely changing Vpp should not make it negative. Or some sort of boundary setting. (edit, reading back, I realize you were saying the same)

Right now, the only waves that are bottom based are I think CMOS, half-sine, rectified-sine (and of course, negative half-sine is top based)
« Last Edit: February 25, 2018, 04:39:19 pm by cybermaus »
 

Offline cybermaus

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #845 on: February 25, 2018, 04:38:16 pm »
I have a couple of those, cybermaus (15v and 12v), and the ouputs are not very well balanced (something like +12.0, -12.7 on the 12v model).  When I made my linear I went for the variable voltage version so that I could ensure that the outputs were balanced, and also to give flexibility to increase the outputs up to +/-15v if a future mod should require it.  The board is a lot bigger, but it still fits nicely in the case with a 15v/9v r-core transformer (as you can see from the photo I posted a couple of pages back).
Odd. They are 7912's, how are they able to mess that up?
I can only see that happen you had a bad 7912 itself. I guess that is possible

If you want to build your own, it's still cheaper to buy the kits from China to get the parts, then do your own layout on Veroboard.
Which then negates that. Maybe the other way around, buy a new local 7912 and solder it onto the chinese PCB.


Anyway. Anything is possible with these cheap things from eBay. Sometimes very good value, sometimes not even worth the space they take up in the garbage.
The only reason I keep buying it (when not in a hurry) is that if I buy local, it is also junk from china, just someone else did the ordering for me.


Unless if Mouser of course. But you know, €20 handling fee, always.
I do sometimes order with them, but not the small stuff.

 

Offline paulca

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #846 on: February 25, 2018, 04:45:00 pm »
The only reason I keep buying it (when not in a hurry) is that if I buy local, it is also junk from china, just someone else did the ordering for me.

Unless if Mouser of course. But you know, €20 handling fee, always.
I do sometimes order with them, but not the small stuff.

I agree.  The UK Ebay at the moment is unfortunately infested with Chinese seller with UK addresses, claiming the item location as UK, when it clearly isn't and takes 2 to 4 weeks to arrive if it ever appears.  You have to read seller names and addresses carefully to filter out the bad ones.

I don't order from Mouser, but RS Components or for a sizable order Farnell.  RS have free shipping and no handling charge for any size of order including a single 0.1p resistor technically.  Though you would feel like a bit of a dick doing that to them.

The downside I find is that for some components the price they leaves you running your hands under cold water cause you feel burnt.  Panel volt meters.  You can find pretty decent ones on Ebay for £5.  RS components, unless you want an analogue one they are in the £30-70 range!  There are many other examples. Breakout boards are fierce price too.  Even something mickey mouse like an SOIC-8 to DIP adaptor board is like £8 each!
"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline soundtec

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #847 on: February 25, 2018, 05:27:47 pm »
Absolutely no need to be intimidated by the numbers when calculating power supplies Paulca.
Take your winding voltage ,multiply it by 1.4 ,now from this you have to subtract the losses across the diodes in the bridge ,then you'll still have to allow at least a few volts extra so that whatever regulator you have can function effectively without dropouts .
Google Duncans PSUd 2 ,thats a really handy little tool for mocking up your psu's before putting money into components ,after a few uses of this software you'll get a feel for what your doing and the intimidation factor will be a distant memory. The more voltage the regulator has to drop the bigger the heat sink will need to be  , also the more voltage drop across the reg also tends to give a quieter noise level at the output.
Best o luck.
« Last Edit: February 25, 2018, 05:38:52 pm by soundtec »
 

Offline fremen67

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #848 on: February 25, 2018, 06:03:12 pm »
Is the CMOS not just simply a quick way to set a signal level square?
Possibly the only special thing is: If you increase Vpp, it does not dive negative.

Whereas if you make your own 3.3Vpp 1.65Voffset square, and increase to 5Vpp, it would accidentally go negative first, before you remembered to also change offset to 2.5V
(I have had that problem, luckily my DUT survived)


But to be honest: I feel all waveforms should consider that 0V case. If I have a Vpp and Offset such that Vbottom is 0V or even positive, then merely changing Vpp should not make it negative. Or some sort of boundary setting. (edit, reading back, I realize you were saying the same)
Yes security for the DUT was the point. In the new firmware, I have at least 3 options: either I just reset the offset when selecting CMOS (as a positive offset could also leads to destruction of the DUT) or I send a null offset when  the CMOS function is in use... or I just let it like this and this will be secured later on with min and max output parameters for all functions... The last one beeing my prefered ATM.
For the other bottom based functions, using the offset does not seem to be a problem.
I'm a machine! And I can know much more! I can experience so much more. But I'm trapped in this absurd body!
 

Offline fremen67

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Re: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
« Reply #849 on: February 25, 2018, 06:52:59 pm »
Tiny update from my side
Better each time :-+

May I suggest these modifications?

W16: DC_AMPL_CH2_OFFSET
W3: DC_AMPL_CH2_GAIN

W26: DC_AMPL_CH1_OFFSET
W5: DC_AMPL_CH1_GAIN
I'm a machine! And I can know much more! I can experience so much more. But I'm trapped in this absurd body!
 


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