EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: JL34 on October 22, 2020, 09:04:10 pm
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Hello,
I am new on this forum. I have read a lot of posts since few months, but i have never took time to post or introduce myself. It is time to change this.
I am 31 years old, living on south of France. I have worked 7 years in an electronic board fabrication factory as technician and finally production manager. 2 years ago i have done professional re-conversion as building craftsman, to work in family business.
Electronic is now a passion rather than a job. I take only pleasure and no more constraints.
I have never had engineer level, only equivalent (i suppose) to English BTEC Higher National Diploma in electronic. I have lost some knowledge with time, but trying to progress as an hobbyist. I continue to develop some boards (mainly with Arduino), around smart home, led lighting, weather data logging, and robotic (motor 12/24V around 100/200W).
Since i have no more access to laboratory test equipment of my last job, i would like to buy some equipment to be comfortable in my hobby at home. Nothing very sharp but something correct. I am looking first for a linear PSU, then an oscilloscope, then bench + hand DMM and maybe a function generator if needed (to generate some PWM mainly). Ok, the stage is set.
I know this is question already posted so many times. I have done search on the forum, have read lot of post, and tried to synthesize my founds :
-Used branded equipment have often better quality
-New equipment have often more functionalities
-For my needs, each can match
-The price can vary a lot depending on the offers and markets (US / EU).
But in the end I find it difficult to make my choice among all these possibilities. I would like to have the "best bang for my buck", and equipment that I could keep for some time. I have some experience (from my last job) with some Agilent pieces but not with Rigol, Siglent. If it is advisable i can wait for some bargain on Ebay.
Here is where i am now :
For the general purpose PSU, from here i can buy Those :
-Used Agilent E3631a for around 350€
-New GW Instek GPE-4323 for 350€
-New Rigol DP832 for 490€
-New Siglent SPD3303X-E for 440€
It's a bit expensive but bang for the buck seems to be great.
For a more powerful PSU for 24V motors, i have yet no idea.
For the bench DMM, i have think about Agilent 34401A. From here, i can find one for 200-250€.
For the hand DMM, i have forgot what Fluke i used on my last job and don't know a good one.
For the oscilloscope, i have use some basic Tektronix at work. But from what I understand there is a big difference between olds DSOs and new ones. So I think about Rigol ds1054z (390€ here) and Siglent sds1104x-e (500€ here).
For functions generator, i have found an offer for an Agilent 33220A for 150€. I don't know if it is a good bang for the buck, i guess it is.
All of these products seem to be good value for money, but are at the high end of my budget for each item.
Here is. As you can read, I am a little lost among all these possibilities and I lack knowledge about new products.
Can you enlighten me please ?
Thanks a lot,
Have a good day.
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Can you solder? Then you should get this PSU and just add the missing parts, a guide for that is on this forum.
https://www.ebay.de/itm/Kikusui-PAN35-20A-0-35V-0-20A-Regulated-DC-Power-Supply/132868975350 (https://www.ebay.de/itm/Kikusui-PAN35-20A-0-35V-0-20A-Regulated-DC-Power-Supply/132868975350)
https://www.eevblog.com/forum/testgear/kikusui-pan35-20a-700w-linear-dc-power-supply/msg3049768/#msg3049768 (https://www.eevblog.com/forum/testgear/kikusui-pan35-20a-700w-linear-dc-power-supply/msg3049768/#msg3049768)
34401 is a decent choice, i'd recommend the BRymen BM235 as a handheld DMM.
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Thanks fornyour reply.
Yes i can solder, i have an Ersa I-con Nano for THTs and a BST-863 for SMDs.
The kikusui PSU seems interresting. I will study that.
Thanks for the handheld DMM. I dont know this brand but it seems good !
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Welcome to the forum JL34.
For the Brymen 235 our moderator Simon has them in his shop in the UK:
https://simonselectronics.co.uk/product/eevblog-brymen-bm235-true-rms/
It's Dave's low priced EEVblog branded DMM that's proven to be a good and popular meter.
PSU's
Be aware for motor drive reverse EMF can damage bench PSU's unless a blocking series diode is used.
Multichannel PSU's can be placed in parallel mode for increased currents so that 30V @ 6A is available.
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Thanks fornyour reply.
Yes i can solder, i have an Ersa I-con Nano for THTs and a BST-863 for SMDs.
The kikusui PSU seems interresting. I will study that.
Thanks for the handheld DMM. I dont know this brand but it seems good !
Look at the other listings of the seller. While that PSU is nice, it is huge and very heavy. Unless you need so much power, you might want to get a smaller one. The seller has many
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Hello,
Salut !
I am new on this forum. I have read a lot of posts since few months, but i have never took time to post or introduce myself. It is time to change this.
I am 31 years old, living on south of France. I have worked 7 years in an electronic board fabrication factory as technician and finally production manager. 2 years ago i have done professional re-conversion as building craftsman, to work in family business.
Electronic is now a passion rather than a job. I take only pleasure and no more constraints.
Same for me. Worked as an electronic engineer for 10 years (including a bit in France, I studied there) and now doing something else.
But in the end I find it difficult to make my choice among all these possibilities. I would like to have the "best bang for my buck", and equipment that I could keep for some time. I have some experience (from my last job) with some Agilent pieces but not with Rigol, Siglent. If it is advisable i can wait for some bargain on Ebay.
I have found that it is more and more difficult these days to find good bargains on used equipment.
I wrote an extensive thread about this and people seem to mostly agree.
Unless you are willing to spend a BUNCH of time scouting eBay, LeBonCoin, and other sites hoping for a deal, you will save a lot of hair by purchasing new.
Here is where i am now :
For the general purpose PSU, from here i can buy Those :
-Used Agilent E3631a for around 350€
-New GW Instek GPE-4323 for 350€
-New Rigol DP832 for 490€
-New Siglent SPD3303X-E for 440€
It's a bit expensive but bang for the buck seems to be great.
For a more powerful PSU for 24V motors, i have yet no idea.
The PSU that has been listed above, Kikusui, is in the united states. You are in France. It does not make sense to purchase a 23kg power supply overseas in my opinion, if you can avoid it. But it is true that if you are looking for a PSU for motors, you might not have a lot of options.
For the bench DMM, i have think about Agilent 34401A. From here, i can find one for 200-250€.
Very good choice.
For the hand DMM, i have forgot what Fluke i used on my last job and don't know a good one.
I personally have an old Velleman entry level DMM and it is far enough. I have been using it for more than 15 years. If you have a good bench DMM, I do not believe you need to invest in an exceptional hand DMM. Just get a basic one.
The Brymen are good, UNI-T has some good ones like the UT61E. I am really not sure why people invest in super expensive hand DMM.
For the oscilloscope, i have use some basic Tektronix at work. But from what I understand there is a big difference between olds DSOs and new ones. So I think about Rigol ds1054z (390€ here) and Siglent sds1104x-e (500€ here).
The Siglent is a bit better, but for what you want to do, it seems like the Rigol will be plenty enough. It is a very popular model. Make sure you know about the fact that it can be "enhanced" ;) search on the forum
For functions generator, i have found an offer for an Agilent 33220A for 150€. I don't know if it is a good bang for the buck, i guess it is.
Are you SURE you need a function generator ? I see a bunch of people buying one and I have no idea what they do with it.
What do you want to do with it ?
All of these products seem to be good value for money, but are at the high end of my budget for each item.
There is a saying, "poor people pay twice"
Lab equipment is very long lived and will service you for years, possibly decades.
It is very important to make sure you purchase the right equipment. Not too expensive but also not too cheap. If you are too cheap, you will have to repurchase in a few years, paying twice.
You can always resell to offset some of the cost but it is a hassle
Here is. As you can read, I am a little lost among all these possibilities and I lack knowledge about new products.
Can you enlighten me please ?
Thanks a lot,
Have a good day.
[/quote]
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The PSU that has been listed above, Kikusui, is in the united states. You are in France. It does not make sense to purchase a 23kg power supply overseas in my opinion, if you can avoid it. But it is true that if you are looking for a PSU for motors, you might not have a lot of options.
Just add up the price, shipping costs and customs fees and compare this to what you can get locally. Shipping heavy items via the eBay Global Shipping Program can be surprisingly cheap sometimes. For me it quotes $56 shipping and $45 import fees, for a total price of about $230. Can you get a similar power supply locally for less shipped?
For functions generator, i have found an offer for an Agilent 33220A for 150€. I don't know if it is a good bang for the buck, i guess it is.
I think that's a good price for that function generator, and I like that generator (I have a similar model), but indeed the question is if you need one. You can probably get a new one from Asian manufacturers like Rigol and Siglent with better specs, but not for that price.
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Welcome to the forum JL34.
For the Brymen 235 our moderator Simon has them in his shop in the UK:
https://simonselectronics.co.uk/product/eevblog-brymen-bm235-true-rms/
It's Dave's low priced EEVblog branded DMM that's proven to be a good and popular meter.
Nice. I will look at his shop. Even better if I can support a forum member.
PSU's
Be aware for motor drive reverse EMF can damage bench PSU's unless a blocking series diode is used.
Multichannel PSU's can be placed in parallel mode for increased currents so that 30V @ 6A is available.
Yes i know, i have already destroyed a PSU at begining of my last job :palm:
Look at the other listings of the seller. While that PSU is nice, it is huge and very heavy. Unless you need so much power, you might want to get a smaller one. The seller has many
I will look others PSU. I juste need to feed some 24V motors around 100-200W. It is an purchase that can wait
Same for me. Worked as an electronic engineer for 10 years (including a bit in France, I studied there) and now doing something else.
Nice coincidence. Do you too thinking that electronics is far more pleasant like a passion rather than job ? ^-^
I have found that it is more and more difficult these days to find good bargains on used equipment.
I wrote an extensive thread about this and people seem to mostly agree.
Unless you are willing to spend a BUNCH of time scouting eBay, LeBonCoin, and other sites hoping for a deal, you will save a lot of hair by purchasing new.
Very interesting. I don't want to spend my life on Ebay and co, but maybe there is actually some good bargain. Like the PSU E3631E for 350€ shipment included, bench DMM E34401a for 200-250€ or function generator 33220A for 150€.
The PSU that has been listed above, Kikusui, is in the united states. You are in France. It does not make sense to purchase a 23kg power supply overseas in my opinion, if you can avoid it. But it is true that if you are looking for a PSU for motors, you might not have a lot of options.
Yes i agree. This is for specific use. But what do you thinking about the others listed PSUs as general purpose ?
-Used Agilent E3631a for around 350€
-New GW Instek GPE-4323 for 350€
-New Rigol DP832 for 490€
-New Siglent SPD3303X-E for 440€
For the bench DMM, i have think about Agilent 34401A. From here, i can find one for 200-250€.
Very good choice.
For the moment I therefore retain the 34401A.
I personally have an old Velleman entry level DMM and it is far enough. I have been using it for more than 15 years. If you have a good bench DMM, I do not believe you need to invest in an exceptional hand DMM. Just get a basic one.
The Brymen are good, UNI-T has some good ones like the UT61E. I am really not sure why people invest in super expensive hand DMM.
I will go on the Brymen one i think.
For the oscilloscope, i have use some basic Tektronix at work. But from what I understand there is a big difference between olds DSOs and new ones. So I think about Rigol ds1054z (390€ here) and Siglent sds1104x-e (500€ here).
The Siglent is a bit better, but for what you want to do, it seems like the Rigol will be plenty enough. It is a very popular model. Make sure you know about the fact that it can be "enhanced" ;) search on the forum
I have read that the Rigol one have a painful UI. What do you think about it ? Does the difference between the two justify the price difference?
For functions generator, i have found an offer for an Agilent 33220A for 150€. I don't know if it is a good bang for the buck, i guess it is.
Are you SURE you need a function generator ? I see a bunch of people buying one and I have no idea what they do with it.
What do you want to do with it ?
I am not sure. I need it to generate some PWM signal with selectable duty-cycle to control motor drivers, leds driver etc, without to program each time an arduino to generate it.
There is a saying, "poor people pay twice"
Lab equipment is very long lived and will service you for years, possibly decades.
It is very important to make sure you purchase the right equipment. Not too expensive but also not too cheap. If you are too cheap, you will have to repurchase in a few years, paying twice.
You can always resell to offset some of the cost but it is a hassle
In France we say something like that : The cheap is expensive. That exactly mean that you will have to buy twice the same thing.
I entirely agree with that. I prefer spend more money on equipment that i could keep a long time.
For now, i must choose to buy or not the used Agilent E3631A for 350€ or buy something else, like GW Instek GPE-4323, Rigol DP832 or Siglent SPD3303X-E.
The offer on E3631A could end soon.
Thanks all for your help ;)
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I will look others PSU. I just need to feed some 24V motors around 100-200W. It is an purchase that can wait
2x 12v car batteries (of the smallest size you can find) wired in series, and a 24v charger that you disconnect while driving the motors.
[Rigol ds1054z (390€ here) and Siglent sds1104x-e (500€ here)] I have read that the Rigol one have a painful UI. What do you think about it ? Does the difference between the two justify the price difference?
my personal opinion is that it is well worth spending the extra to get the siglent SDS1104X-E. the interface is snappier and far more usable, and you get double the sample rate (using all 4 channels: 500Msps (siglent) vs 250Msps (rigol)). the rigol can be boosted to 100MHz bandwidth, while the siglent can be boosted to 200MHz. in the case of the siglent, this takes around 10 minutes to do over a network connection to the scope. i own an SDS1104X-E myself.
[from uski] I am really not sure why people invest in super expensive hand DMM.
if things go south in a major way, a good DMM may be destroyed, but will contain all the damage within its casing. whereas a not-so-good DMM will kill the person holding it. my personal preference is a fluke of some variety, i use both a fluke 12B and a couple of 77's. others may scoff that i am being too cautious.
cheers,
rob :-)
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For the oscilloscope, i have use some basic Tektronix at work. But from what I understand there is a big difference between olds DSOs and new ones. So I think about Rigol ds1054z (390€ here) and Siglent sds1104x-e (500€ here).
Both are good and equivalent value for money. The only way to answer this question is "how much do you want to spend"?
In this price range there's also the GW-Instek GDS1054B. If you can get a good price on one of those (less than the Siglent) then get that instead.
For multimeter I'd look at Brymen. Very easy to buy in the EU.
http://www.brymen.eu/ (http://www.brymen.eu/)
I have read that the Rigol one have a painful UI. What do you think about it ? Does the difference between the two justify the price difference?
The Rigol UI is better for some things, worse for others. I wouldn't base a decision on that.
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Everyone has their perspective and use case, so I can only tell you what I've observed. I have some of the devices you mention, I've had others and still others have passed through as repairs. Here's my take:
Skip the Agilent 3631A. They are expensive, they are not bulletproof and repairs can be an issue because HPAK doesn't provide much usable service info. It is a sort of almost unit-replacement system. The other ones you mentioned may not be much better, but I'd prefer a new, supported non-serviceable unit to an old unsupported one. Of the three new ones, I couldn't say, except that it seems like a lot of money to spend right now on something that won't even support your primary use, which would seem to be 24V @ 10A or so. I have no idea what is available second-hand in your area.
The Agilent 34401A is an excellent choice if you need the precision that it offers. However, using all of its features requires punching a lot of buttons to dig through the menus and find that setting you want, like input impedance or AC filtering or whatever. Still, at that price, it would be hard to beat. Keep in mind that like many bench DMMs of its era, it does not excel at current measurement. I think the question you have to ask yourself is if you really need a bench meter. If so, and you can get a 34401A in good condition for that price, go for it. It will probably appreciate in value the way things are going.
For handheld DMM I buy Fluke, they've earned my business by greatly exceeding reasonable expectations over many years. We don't have reasonable access to Brymen in the US, but many people seem to like them and think they are a better value, so I won't tell you not to buy Brymen. You may want to reconsider whether you really need a bench meter at all, perhaps a top-of-the-line handheld might do it. OTOH, a 34401A and a Fluke 101 would cover a lot of ground for 300€ combined.
With oscilloscopes, you probably can't go wrong. I have a dozen, including 5 or so DSOs, and the one I grab the most often is the Siglent 1104X-E. I had a Rigol 1054DZ and the Siglent was a huge upgrade. It isn't the quickest, easiest or most intuitive one to setup and use, but it has almost every feature you would look for in a standard DSO. I think the MSO functions and decoding are regarded as not so good, but that's not my use for it.
The Agilent 33220A for 150€ seems a fairly good deal if the single channel and limited bandwidth are good enough for you. The floating output is a pro feature you don't get on some other cheaper brands, but keep in mind it is low-voltage floating only.
Your first project may be to build your own 12/24V supply. Does that need to be adjustable or just 12 and 24 volts exactly, or would a battery and charger system work?
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if things go south in a major way, a good DMM may be destroyed, but will contain all the damage within its casing. whereas a not-so-good DMM will kill the person holding it.
That it only a issue when working in industrial or distribution settings, for a hobby workbench it do not matter.
With that said, I do like high end DMM's, they always work and show precise values (At least if you know what you do). One DMM that is a good compromise is Brymen BM257 with a computer interface (The interface is extra).
For power supplies I like TTi, especially QL355P, it has numeric keys and encoder, either can be used to set voltage, it has a computer interface (Only P models), but it cannot deliver that much power (About 100W). For high power I use another TTi supply (1200W) with the same functions.
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The "spend a bit more" argument doesn't stop at Siglent.
For 100 Euros more you can have something better than a Siglent. What's an extra 100 Euros when you're looking at something that will last for 10 years.
For another 200 Euros you're in Keysight (https://www.batronix.com/shop/keysight/all-oscilloscope.html) territory. Keysight is an "A-brand" oscilloscope. nb. Their "2-channel" oscilloscopes are actually 3 channel MSOs (2 analog+1 digital) although Keysight never seems to mention that)
It's turtles all the way up. :popcorn:
Bottom line: There's happy Rigol owners, happy Siglent owners, happy Keysight owners.
All have their share of problems (https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/1675/).
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Concerning the PSU for motor, I'll put it off until later. This is not my primary use. It is the least common. Maybe i have misspoke.
24V batteries would be sufficient like Robert said. And build a PSU for thos specific use could be a nice project for later.
Contrary to what I thought, buying a used Agilent power supply doesn't seem to be a good idea. If no one disputes this, I'll pass up the offer for the E3631a.
So i need to find a new one to buy, for general purpose. It is my most needed equipment. Like i have said, it is to powering logic circuits boards, arduino, etc. So 25-30V with 2-3A should be sufficient. But i don't know new products and I have to rely on your advice. GPE-3323 and GPE-4323 seems to be a good choice, 320€ and 350€ from here.
I think about the need to have a bench DMM. It is not an obligation for me, but i appreciated the way i used both bench and handheld DMM in my last job. The bench DMM was connected to some test points with soldered miniature wires, and i used handheld DMM to fast measure and control voltages of interest. Both in same times.
I think a good handheld DMM with an accurate bench DMM would be great. Handheld DMM to general purpose and fast measure, and bench DMM for accurate or long measurement :
-A 50-100€ handheld DMM, lUNI-T UT61E (100€) or Brymen BM235 (88€) or BM257s (105€).
-And a bench DMM, like 34401a. I don't know other valuable for money bench DMM.
Oscilloscope is a complex subject. 500€ is already an important amount for me. I understand it is an important expense tag, and an important equipment. I could reach 600€ if needed, but i prefer not. While waiting for a possible better choice, I retain the Siglent SDS1104X-E or GW Instek GDS1054B (500€ both from here). Is there really a good reason to go for Keysight and reach 600€ for my actual use and near future use ?
33220A function generator is a bonus. If i could find cheaper way to produce PWM signal with bench equipment, i will go this way.
One more time, thanks for your replies and advice. Those are precious information for me
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Unless you really need to measure 4W ohms (with 4 cable Kelvin connection) I would skip benchtop multimeter.
I would also skip any Fluke because they are too expensive for features (they are good quality, but light on features.) Buy Brymen BM869S that will replace most of features of benchtop, very good quality (on par with Fluke) very good accuracy... For one Fluke 87V you can buy 2 BM869S...
Also don't buy used old E3631A. Buy GWInstek GPE4323, it also have load function... Just make sure it has Ethernet built in, it cannot be added later...by connecting it to PC you can control it with program... Making all kinds of things possible..
Scopes seem to be like religion, everybody thinks his is the right one...
Cheapest real scope is DS1054Z, it has it's deficiencies, but mostly does the job.
Siglent SDS1104X-E is more powerful hardware, better sampling (two converters instead of one) better sensitivity and lower noise on inputs... It is better scope, but also bit more expensive.. I would personally go with that one if you can afford it.
Keysight is waste of money at this segment..
I would not spend more money on scope. It will take few years until you outgrow it, if ever, depending on what are you doing. You will cross that bridge when you get there..
For protocol decoders buy cheap USB logic analyser from ebay and run it with Pulseview..
33220A is very simple and basic 1 ch gen... There is this small cute Uni-T AWG (search on the forum here) that is much better device for that money...
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Is there really a good reason to go for Keysight and reach 600€ for my actual use and near future use ?
The 600€ "Edu" Keysights are quite limited functionality. You'd have to spend a bit more.
For 600€ you should look at the Micsigs (https://www.batronix.com/shop/oscilloscopes/Micsig-STO1104C.html). :-)
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33220A function generator is a bonus. If i could find cheaper way to produce PWM signal with bench equipment, i will go this way.
if it is just PWM signals you want to generate, might i suggest you look at some sort of micromite. the E-28 is a good option if you want something ready built:
https://www.rictech.nz/products/20/MicroMite-Explore-28-module (https://www.rictech.nz/products/20/MicroMite-Explore-28-module)
these are microcontrollers (PIC32MX170), containing firmware to allow programming in BASIC via a terminal emulator on an attached PC - ie, interpreter, editor, storage all reside on the chip - and have a couple of PWM channels that with just a few lines of BASIC code can be configured to do just about anything you are likely to want. for more general information on the micromite see:
https://geoffg.net/micromite.html (https://geoffg.net/micromite.html)
the firmware is a free download, so you can just buy MX170 chips from microchip and program them yourself. the MX170 is available in a 28-pin DIP package.
disclaimer: i was involved in the E-28 design. background here: https://diyodemag.com/features/mighty_micros (https://diyodemag.com/features/mighty_micros)
cheers,
rob :-)
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33220A function generator is a bonus. If i could find cheaper way to produce PWM signal with bench equipment, i will go this way.
You could start with a "PWM module" from ebay/aliexpress for just a few dollars:
[attach=1]
An Arduino is also a fairly convenient way to produce a PWM signal and also inexpensive.
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For PWM generation i prefer somethings with case, display and knob. I will search about PWM modules with those characteristics.
But for few tens of € maybe it could be smart to step to the 33220A (150€) ?
For the PSU, a consensus seems to be emerging around GW Instek GPE-4323. I retain this model until a best one come.
For o-scope, SDS1104X-E seems to be the right one. What about GW Instek GDS1054B ?
For DMM, 2N3055 give me doubt. Having only on handheld DMM could reduce the bill and be sufficient.
I would still like to find a bench DMM model, a cheaper one and not so accurate, to continue using double DMM like i done in my last job.
Maybe is there some UNI-T that can suit. I will look this. Maybe to wait bargain on Ebay..
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I've got to say when it comes to lab power supplies, I'm a sucker for decimal keypads. Unless they are special purpose or completely analog units, I wouldn't accept only an encoder U/I since you are so much faster entering a certain voltage which I'll do in at least 90% of the situations. And if it's got to be "knob control", I'll never accomodate myself with this coarse/fine rubbish which IMO is just the a cheap excuse for a proper ten-turn pot. One accidential touch of the coarse control and your DUT may be history.
The GW Instek electronic load function is a very nice extension of a classic lab supply and probably quite useful at times. But still, I prefer Rigol's DP832 due to the mechanical rigidity and the possibility to rest it on its rear. I always seem to be out of bench space so it's very convenient to place a PSU (...or several...) on the floor next to the bench. Price-wise, I didn't find much difference between the GWI and Rigol.
But of course, eveyone has got differnet priorities when it comes to test gear...
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True, the 33220A is an older design, but at 150€ I think it is a bargain. Some of the newer ones have 2 channels, higher frequency, more AWG memory, a fancy UI etc, but you may not need that and they will cost significantly more. The Agilent is a solid, dependable instrument (which can not be said for random modules from aliexpress) with decent specs and it has a floating output, if you need that.
I have an E3631A and I still use it regularly, but I would hesitate to pay 350€ for it. It is a decent power supply with clean output (and contrary to what has been said, a full service manual with schematics is available), I just don't love the usability. Setting the voltages and currents with the rotary encoder is slightly annoying and unfortunately it only ever shows one channel at a time. I use it if I just need two or three, fixed voltages and don't really need to monitor them all the time.
I also like TTi power supplies, QL series if you prefer a keypad or PL series if you prefer old-school knobs. Probably out of your budget new, but worth a look if you can get a good deal used.
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Many well intentioned advice here, but must keep the priorities. OP has limited resources.
So best price performance is important. Also it is important to buy as much capability to start with.
TurboTom is right, I also like DP831 I have. And Load function in GW Instek is not as fully featured as my Maynuo load. But 4 Ch Instek is good PSU, for less money than DP832 and free load functionality thrown in.
I think it's a steal.. And it has numeric keyboard. I'm actually thinking of getting one for my second workplace..
Also, I firmly believe benchtop 6.5 digit is not needed for most people. Nice to have, but not needed. Unless you're doing something specific and than it is necessary. In which case you will know it for sure.
One thing that is very useful is 4 wire Ohms. In which case you maybe need micro-ohmmeter ?
On top of that, advanced handhelds, like BM869, have most of accuracy and features of benchtop for general work. Get that one and one smaller, cheaper, to carry around and secondary measurements, and you're set...
Also have in mind your fancy PSU will show you voltage, current and power of your DUT... And if you're connect PSU with PC you can log and measure directly from there..
I wouldn't buy AWG with only one CH... that limits it's use very much....
Also I'm sceptical about buying anything used as first and only equipment. You need to have base equipment that works to be able to repair something. But with scope you can verify AWG functions..
Little GW-Instek 1000B is better scope than Rigol DS1054Z. But Siglent SDS1104X-E has two 1GS/sec A/D converters and bit better input ch specs. GW Instek scope that has same A/D converter setup is 2000E series that is better scope than Siglent SDS1104X-E but is much more expensive....
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Also, I firmly believe benchtop 6.5 digit is not needed for most people. Nice to have, but not needed. Unless you're doing something specific and than it is necessary. In which case you will know it for sure.
One thing that is very useful is 4 wire Ohms. In which case you maybe need micro-ohmmeter ?
That last digit may not be all that important, but I find that the high impedance DC input is a must-have once you've had it. The Fluke 8842A used to be a very good option for that reason, but the ones you find nowadays are either very expensive or in poor condition--or both. If he can get a good 34401A at that price, I would recommend it.
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...
But 4 Ch Instek is good PSU, for less money than DP832 and free load functionality thrown in.
...
The OP was referring to the GPE-4323 which apparently hasn't got a load function and obviously no numeric keypad. The price is attractive, though:
https://www.tme.eu/gb/details/gpe-4323/multichannel-power-supplies/gw-instek/?gclid=EAIaIQobChMIjp2Vq8LN7AIVFOd3Ch3KGgeREAYYBSABEgKjsPD_BwE&brutto=1 (https://www.tme.eu/gb/details/gpe-4323/multichannel-power-supplies/gw-instek/?gclid=EAIaIQobChMIjp2Vq8LN7AIVFOd3Ch3KGgeREAYYBSABEgKjsPD_BwE&brutto=1)
IIRC, the one with the load is the GPP4323 which is considerably more expensive, also more than the DP832.
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Hum, i have not thinked about keypad comfort and accident probability of knob. I have forgotten it, it was happened to me in my last job...
It will be nice to have a keypad, but price is not the same. For now there is a discount on the GW Instek GPE-4323 (350€)https://eleshop.fr/gw-instek-gpe-4323.html (https://eleshop.fr/gw-instek-gpe-4323.html), but not on the Rigol DP832 (490€)https://eleshop.fr/alimentation-de-laboratoire-programmable-rigol-dp832.html (https://eleshop.fr/alimentation-de-laboratoire-programmable-rigol-dp832.html). 140€ is not a little difference... I don't know if that justify the additional features.
For DMM, you were several to say that is not needed to have both handheld and bench. I think there is a consensus, and i could always buy a bench DMM later. I will go for BM869 with my actual cheap handheld DMM. That's okay. And I could certainly find a bargain on a 34401a on ebay later, there is regularly new ones with nice price.
About the 33220A i haven't decided yet. Maybe if I still have some euros left after the rest.
For the O-scope, this seems to be consensus too around Siglent SDS1104X-E. I think i will go this way.
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...
But 4 Ch Instek is good PSU, for less money than DP832 and free load functionality thrown in.
...
The OP was referring to the GPE-4323 which apparently hasn't got a load function and obviously no numeric keypad. The price is attractive, though:
https://www.tme.eu/gb/details/gpe-4323/multichannel-power-supplies/gw-instek/?gclid=EAIaIQobChMIjp2Vq8LN7AIVFOd3Ch3KGgeREAYYBSABEgKjsPD_BwE&brutto=1 (https://www.tme.eu/gb/details/gpe-4323/multichannel-power-supplies/gw-instek/?gclid=EAIaIQobChMIjp2Vq8LN7AIVFOd3Ch3KGgeREAYYBSABEgKjsPD_BwE&brutto=1)
IIRC, the one with the load is the GPP4323 which is considerably more expensive, also more than the DP832.
Tom,
thanks for setting me straight.. My mistake, sorry..
Regards,
Sinisa
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Hello,
If you have both a benchtop multimeter and a handheld multimeter, when you are going to need to measure something quickly, you will always take your handheld multimeter.
I have a benchtop multimeter but I use it much less often than my handheld multimeters and only for very specific things.
I also have a Brymen BM869s but Im not sure you really need one.
For the price of BM869s, you can have several very accurate and cheaper DMM and also buy yourself an LCR meter if you need it.
It is a big and heavy DMM.
In some cases this can be useful, in others a small compact multimeter is more suitable.
It depends on what you are trying to measure, the voltages you want to measure and the level of protection you need.
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A 6½ digit bench top meter is very good when you need precision or four terminal ohms measurement, the bench meter with less digits usually also supports four terminal ohms.
One of the advantages of many bench top meters is the computer connection (Not all bench meters support it) and that they never run out of batteries (very useful when logging).
The BM257 I suggested earlier is a handheld that includes computer connection and one of the cheapest Brymen meters when you want the computer connection.
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Hum, i have not thinked about keypad comfort and accident probability of knob. I have forgotten it, it was happened to me in my last job...
It will be nice to have a keypad, but price is not the same. For now there is a discount on the GW Instek GPE-4323 (350€)https://eleshop.fr/gw-instek-gpe-4323.html (https://eleshop.fr/gw-instek-gpe-4323.html), but not on the Rigol DP832 (490€)https://eleshop.fr/alimentation-de-laboratoire-programmable-rigol-dp832.html (https://eleshop.fr/alimentation-de-laboratoire-programmable-rigol-dp832.html). 140€ is not a little difference... I don't know if that justify the additional features.
For DMM, you were several to say that is not needed to have both handheld and bench. I think there is a consensus, and i could always buy a bench DMM later. I will go for BM869 with my actual cheap handheld DMM. That's okay. And I could certainly find a bargain on a 34401a on ebay later, there is regularly new ones with nice price.
About the 33220A i haven't decided yet. Maybe if I still have some euros left after the rest.
For the O-scope, this seems to be consensus too around Siglent SDS1104X-E. I think i will go this way.
Sorry for my mistake with PSU.
To make it simple, what I want to say is that there seem to be many people who think you have to have ALL the possible instruments from the beginning. Of course you don't, you need basic things at beginning, and you will get more later, if you keep the hobby.. What else you buy will depend on what you will do. RF electronics have one set of instruments, audio will have other. Digital and analog will differ. Maybe you will enjoy robotics, so that is going to be mechatronics....
To start you don't even need fancy PSU. Many digital devices can be powered with power bricks. Lab PSU is nice because of current limiting and variable voltage. Many devices don't need that.
Also, you will need more PSU as time goes by. You will buy (or build, or buy used and repair) them as you go. So you can buy simpler device now.
What you do really need is one good meter, one simpler meter and oscilloscope..
With that you can start and do a LOT.
If you need audio frequency generator you can use PC (or phone) audio card. Lot of audio measurements are better with audio card and software.
And go from there. Start making projects, and you will soon see what would be nice to have to make your work better.. Maybe preheater for PCB will be more important. Or microscope.
Good part of cost in my lab is tools, soldering equipment, cables, various RF adapters, attenuators, probes, etc..
As I said, it is smart to start small, and then upgrade as you go.. Otherwise you might end up owning too much stuff that you never use.. We call it TEA syndrome here on forum >:D
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@JL34 -- on the power supply situation:
The lack of contemporary display of preset and measured voltage / current on the GPE-4323 as well as the complete absence of a power readout is quite a difference that would leave a bitter taste in my mouth. Moreover, there's only two sets of displays for the four channels. I don't know your opinion regarding "improving" your gear but the DP832 can be turned into a DP832A (except for the colourful front...) without any difficulty. This procedure can be reversed as well - in case of a warranty claim. The DP832A plays in a completely different league.
Agreed - 140 euro is a lot of money. But spending 350 on a power supply that you possibly may want to replace in forseeable time is also soemthing that should be kept in mind. I can conclude like that: As long as the required power was within its range, my DP832(A) so far never made me wish to replace it with a different unit. I valued it so much that I got another Rigol unit for the more hefty applications, the DP811 (signle channel 20/40V; 10/5A), which I have to admit, is not as "well mannered" as the DP832. ;)
Just some food for thought...
Edit: @2N3055 is right - you may get along pretty well without an expensive PSU initially and maybe use an inexpensive switcher until you've got a better idea what kind of performance you really need.
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Hum, i have not thinked about keypad comfort and accident probability of knob. I have forgotten it, it was happened to me in my last job...
Maybe you are not aware the modern PSU has a front panel Lock button to prevent settings being changed.
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I thought a little more about my needs and what you have said about the fact to start with only minimal equipment and wait to see.
Wise advice. I don't want to fall in TEA syndrome :) (where does this expression come from?)
I don't need very accurate DMM. A BM257s should do the job. 0,01 mV and 0,1µA accuracy is more than sufficient for my actual and near future needs. And it have computer connection possibility. For 105€ here, it could be my final choice.
With this one i should find one cheaper and less accurate to measure current and voltage simultaneously when i work on current drived leds modules (to fine adjust current and voltage output of CV/CC drivers). 1mV/1mA should be more than sufficient. A suggestion ?
About PSU, i will limit things. My actual works concern smart home modules, weather station, arduino, and led lighting. So the powerest is led modules, max 50V and 1.5A. So my minimal needs are :
-current limiting and variable voltage (to prevent things from going even worse when things go wrong)
-10mV/1mA accuracy (i suppose)
-3 channels, one to power the logic board (3.3V or 5V) and 2 possibly in series to reach about 50V/1.5A minimum
Those needs are invariable and any PSU that I could consider must meet these needs.
In suggested PSU, the first to meet these conditions was the GW Instek GPE-4323. And we immediately fall back to what TurboTom said :
The lack of contemporary display of preset and measured voltage / current on the GPE-4323 as well as the complete absence of a power readout is quite a difference that would leave a bitter taste in my mouth. Moreover, there's only two sets of displays for the four channels. I don't know your opinion regarding "improving" your gear but the DP832 can be turned into a DP832A (except for the colourful front...) without any difficulty. This procedure can be reversed as well - in case of a warranty claim. The DP832A plays in a completely different league.
Agreed - 140 euro is a lot of money. But spending 350 on a power supply that you possibly may want to replace in forseeable time is also soemthing that should be kept in mind. I can conclude like that: As long as the required power was within its range, my DP832(A) so far never made me wish to replace it with a different unit.
I can't success to make a choice with so relevant sort of advice.. ;)
About oscilloscope, nothing seems to have change. The Siglent SDS1104X-E seems to be the right choice.
About soldering equipment like 2N3055 have discussed, it is a parallel subject for me. I am already looking to preheater, third hand clamps with magnifying glass and lighting. But those equipment is cheaper and it is not a priority for now.
So for now the main difficulty stay the PSU choice
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Look again at SPD3303X-E, 370 Euro and almost perfectly fits your needs. Improve it ;) to the X model and then exactly fits your needs.
https://int.siglent.com/products-overview/spd3000x/
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TEA syndrome (test equipment acquisition syndrome)..
Look, it's simple. How much money do you exactly are willing to give for PSU?
Set a hard limit.
You take that and list becomes much shorter.
On that note, Rigol DP832/831 is best price performance in lower price class. There is a reason for it being so popular..
3 full channels, measurements, connectivity... It's low noise too.
Siglent has some nice PSU-s too, SPD3303X-E is good PSU, but only 2 ch are full, third one is not fully featured...Rigol DP832 that has 3 full channels is only 30-40 € more..
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TEA syndrome (test equipment acquisition syndrome)..
I have found the thread on this thing. I know this kind of behavior, i have the Tool Acquisition Syndrome >:D
Look again at SPD3303X-E, 370 Euro
It is 370€ without taxes (VAT) here. Taxes are 20%... So finally it is 444€.
Look, it's simple. How much money do you exactly are willing to give for PSU?
Set a hard limit.
You take that and list becomes much shorter.
It is not that simple. I can reach the DP832 price. But only if it's really worth the cost.
GW Instek GPE-4323 :
- 350€ with temporary discount
- 4 full channels, 2x 32V/3A, 1x 5V/1A, 1x 15V/1A
- Setting accuracy 10 mV / 1 mA
- Ripple ≤ 1 mVrms / 3 mArms
- Display 4.3" TFT LCD
- Keypad : No
- Special feature : Load function Constant voltage, current
SPD3303X-E :
- 445€
- 2 full channels + 1 fixed, 2x 32V/3.2A, 1x 2,5/3,3/5,0V/3.2A
- Setting accuracy 10 mV / 10 mA
- Ripple ≤ 1 mVrms
- Display 4.3” LCD color
- Keypad : No
- Special feature : LAN, USB
Rigol DP832 :
- 490€
- 3 full channels, 2x 30V/3A, 1x 5V3A
- Setting accuracy 10 mV / 1 mA (1 mV / 1 mA hacked to DP832A)
- Ripple < 350μVrms / 2 mArms
- Display 3,5" TFT LCD
- Keypad : Yes
- Special feature : USB, RS232, LAN, USB-GPIB, digital IO
The GW meets all my minimum requirements, but has no scalability for my future needs.
The Siglent one meets all my minimum requirements too, has better connectivity and more functions, but with 2 full channel instead of 4 on GW one. It doesn't seems to justify the 100€ increase price. So I can consider that it is excluded.
The Rigol one meets all my minimum requirements, has great scalability, a keypad, better connectivity and much more functions. With 3 full channel instead of 4 on GW one. The fourth channel not being very useful, 3 channels are sufficient i think.
The 150€ increase is not a little amount, but it give me great scalability and keypad. Everything will be played out there.
According to you, what are the functions of interest available on the DP832 ? And does it justify 150€ increase ?
We advance, slowly but surely :-+
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TEA syndrome (test equipment acquisition syndrome)..
I have found the thread on this thing. I know this kind of behavior, i have the Tool Acquisition Syndrome >:D
We all do... :palm: I was just hoping maybe we could save just one of us...Just one... To give us, others :scared:, the hope and show us the way .... :-DD
As for DP 832/831, like Tom already said, biggest thing you will see first is fact that you have 3x4.5 digit voltmeter and 3x4.5 digit amperemeter and wattmeters per channel.
Also you can remote control it from PC, which includes both settings and measurements.
Just typing in voltage is quick.
Voltage is really clean, on mine noise is less than specified...Most of the noise I measure come from my (very noisy) environment.
It is just very easy to use, and after you get used to fact that everything is there at the fingertips, and that the screen shows most of interesting data at all times (and you don't need to connect any instruments to measure) it is hard to get back to using simpler devices.
It is well worth the money in my opinion. Like Tom, I also rarely use any other PSU since I got DP831. I fire up other ones when DP831 doesn't have enough current or I need 4th or 5th channel..
But I also worked for years with several simple linear noname 30V/3A with simple 3 digit V/A and made loads of work, that fed my family and bought me loads of expensive equipment.
So my (personal) opinion is, that if you can afford it, you will like it and be glad you have it. If buying it would mean giving up on something other that is useful, that I wouldn't do it.
I have this philosophy about equipment, instruments and tools. I look at it as a capability. A tool or instrument gives you capability to do something. A 19mm wrench gives you capability to unscrew M19 nut.
If you don't have any kind, you can't do it with fingers. But even cheapest wrench will help you unscrew that M19 nut. If it is low quality material, it won't last long, but in meanwhile you will have capability to unscrew M19 nut. If you are auto mechanic, you might want to buy one that is made from good material (so it will last), has accurate dimensions (not to damage nuts and bolts and doesn't skip), has ergonomic handle (so you don't hurt your hand)... But if you don't use it 8 hours a day every day, and price is really expensive for a fancy professional set, you might get away for a long time just by having a set from LIDL..
That is why I buy tools as a need arises. If I use something just occasionally, i try to borrow it. If that is problematic, I then have to buy it. If I'll be using it every day, then I know I have to buy something that will work with me, not against me, and buy stuff that is good. Sometimes it will be Rigol, sometimes Siglent, sometimes Brymen, sometimes Keysight, sometimes Fluke, or maybe UNI-T if it fits the bill...
Regards,
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Just out of curiosity, I looked a little more closely at the manual and possibly for a video review of the GPE-4323 and found something on its three-channel brother, the GPE-3323: https://youtu.be/xHiWE8xCxqE (https://youtu.be/xHiWE8xCxqE)
I highly recommend to watch that review if you already haven't: I immediately spotted several characteristics that would be complete "no-go's" for me: Other than I expected, all the adjustments are done by single-turn pots, and not encoders! This means, on the two main channels, you've got about a volt every ten degrees of angle. This is highly risky when powering modern low-voltage digital stuff since a few hundered millivolts can be enough to release the magic smoke. And that's a single, accidental touch of the adjustement knob away... The available voltage lock function for the main channels may help here (albeit it may alter the set output voltage by a few tens of milliviolts ::)) but you've got to make it a habit to use it. Moreover, there's only a single enable/disable pushbutton that affecs all channels. Individual on/off switches? Nope!
So the GPE-4323 will probably get the job done to supply the DUT but it cannot be considered a "Precision Supply" like the other two contenders. Thus, IMO, the value for money ratio of this unit is actually the worst of the three. But YMMV... ;)
P.S. Can someone explain to me what that nonsense of emulating seven-segment digits on TFT displays is all about? Especially, if non-lit segments are dimly depicted as well (like on the DP800 "non-A" series |O). A nice, fixed-pitch sans serif font is much easier readable... It becomes completely obvious that the seven segment arrangement was just a makeshift solution to simplify displays (electromechanical, edge-lit, Nimo or Nixie vs. the first incandescent, Panaflex or VF displays). So why that tendency to "celebrate" it in modern equipment?? If I want a seven segment display, I power up a Keithley "brownie" ;).
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I seem to agree with Tom on most points here. :-+
GW Instek GPE-4323 doesn't have load function, I confused it with GW Instek GPP-4323.
GPE-4323 is very unremarkable and limited PSU, no better than some noname units.. It is no match to DP832 or SPD3303X-E.
SPD3303X-E is good device, but for me no numeric keyboard and "half baked" third channel is reason why I would go with DP832.
Just one note about DP832 that I don't like: It's overvoltage protection is not hardware crowbar circuit. It is software function, and slow. Also, it is made stupidly, so you can enter too high voltage on keypad, and then it will put that overvoltage (voltage more than specified in limit) on output, quite happily, and wait for some 500 milliseconds before disabling it. So you can set OVP to 6V, enter 15V on ch, enable it, and it would happily output 15V, wait for 500 msec and then disable ch because it just realised it was too much..
It would be trivial to do in software so it simply won't let you enable CH if you are trying to set voltage higher than OVP, or if you type in or set too high voltage with encoder, to simply refuse those invalid numbers...
@TurboTom, I also don't like that many of devices nowadays are made with user interfaces made to "look cool" (at least in opinion of those who made it), instead of being easy to use, informative and easily readable..
Like with movies, that have a story adjusted to look good on a trailer, not to make a good film. Because trailer decides if you go and buy ticket. Once you buy the ticket, nobody cares if you actually liked the film...
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@2N3055:
There are actually a few applications that I could think of where Rigol's approach to permit to enter higher voltages than the limit, and enable the output, would actually make sense:
Consider having constant current devices (a rechargeable battery for example) where the supply should be shut down after a certain voltage has been reached. Or production testing of DC motors: Spin it up at constant current and record the voltage slope for a pass/fail decision. End the cycle when a certain voltage has been reached (by means of OVP) which corresponds to a certain motor rpm.
But I completely agree with you that the reaction time of the OVP/OCP function should be way faster (any maybe even made adjustable so the user may decide what kind of reaction he really needs in his particular case).
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We all do... :palm: I was just hoping maybe we could save just one of us...Just one... To give us, others :scared:, the hope and show us the way .... :-DD
It can't happen, especially in electronic. It is a hobby / work of thoroughness and perfectionism.. We are all doomed >:D
As for DP 832/831, like Tom already said, biggest thing you will see first is fact that you have 3x4.5 digit voltmeter and 3x4.5 digit amperemeter and wattmeters per channel.
...
It is just very easy to use, and after you get used to fact that everything is there at the fingertips, and that the screen shows most of interesting data at all times (and you don't need to connect any instruments to measure) it is hard to get back to using simpler devices.
Just for those 2 things, for me it's worth it.
I have this philosophy about equipment, instruments and tools. I look at it as a capability. A tool or instrument gives you capability to do something. A 19mm wrench gives you capability to unscrew M19 nut.
If you don't have any kind, you can't do it with fingers. But even cheapest wrench will help you unscrew that M19 nut. If it is low quality material, it won't last long, but in meanwhile you will have capability to unscrew M19 nut. If you are auto mechanic, you might want to buy one that is made from good material (so it will last), has accurate dimensions (not to damage nuts and bolts and doesn't skip), has ergonomic handle (so you don't hurt your hand)... But if you don't use it 8 hours a day every day, and price is really expensive for a fancy professional set, you might get away for a long time just by having a set from LIDL..
That is why I buy tools as a need arises. If I use something just occasionally, i try to borrow it. If that is problematic, I then have to buy it. If I'll be using it every day, then I know I have to buy something that will work with me, not against me, and buy stuff that is good. Sometimes it will be Rigol, sometimes Siglent, sometimes Brymen, sometimes Keysight, sometimes Fluke, or maybe UNI-T if it fits the bill...
We back to what we have said before : The cheap is expensive. The cheapest 19mm wrench will do the job. But you will have to buy one other wrench pretty fast if you use it regularly. And more, if you damage the M19 nut with it, jack-pot ! You have won your day.
PSU, oscilloscope and DMM could be very often used on my electronic hobby. Much more often than a function generator. So for them i will not go for LIDL ones ;D
all the adjustments are done by single-turn pots, and not encoders! This means, on the two main channels, you've got about a volt every ten degrees of angle. This is highly risky when powering modern low-voltage digital stuff since a few hundered millivolts can be enough to release the magic smoke. And that's a single, accidental touch of the adjustement knob away... The available voltage lock function for the main channels may help here (albeit it may alter the set output voltage by a few tens of milliviolts ::)) but you've got to make it a habit to use it.
I have read that knobs can be tweaked with 10 turn pot, but it will avoid warranty.
Moreover, there's only a single enable/disable pushbutton that affecs all channels. Individual on/off switches? Nope!
Thanks for this information ! It is totally prohibitive. Just for that i can go my way.
GW Instek GPE-4323 doesn't have load function, I confused it with GW Instek GPP-4323.
GPE-4323 is very unremarkable and limited PSU, no better than some noname units.
This is the final blow to the GPE-4323.
So finally i will choose :
PSU : Rigol DP832
O-scope : Siglent SDS1104X-E
Accurate DMM : Brymen BM257s
I blow up my initial budget, but i think it is good invested money and that i will glad my choice.
I will try to negotiate some discount from seller.
Thanks a lot again for your advice and given information.
I am still impressed by the forum's maturity, the lack of unpleasant remarks, and quality of discussion. Very glad to found it ! :-+
Edit :
Is there a way to get around the 500ms latency problem on overvoltage protection and mostly on overcurrent protection of DP832 ?
This can be damaging when i work on low voltage boards.
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@2N3055:
There are actually a few applications that I could think of where Rigol's approach to permit to enter higher voltages than the limit, and enable the output, would actually make sense:
Consider having constant current devices (a rechargeable battery for example) where the supply should be shut down after a certain voltage has been reached. Or production testing of DC motors: Spin it up at constant current and record the voltage slope for a pass/fail decision. End the cycle when a certain voltage has been reached (by means of OVP) which corresponds to a certain motor rpm.
But I completely agree with you that the reaction time of the OVP/OCP function should be way faster (any maybe even made adjustable so the user may decide what kind of reaction he really needs in his particular case).
What you say is perfectly OK. But that kind of function would be called something else than "over voltage protection" . OVP should be, simply, "never to be exceeded" limit.
In case of constant current mode it upper limit on compliance voltage that, if exceeded, would prompt instant shutdown..
For this sort of use, there are triggers and monitor mode. In monitor mode you can set DP832 to beep, show message or disable output if certain voltage, current or power condition is met.
Reaction time could have been in microseconds, if they didn't save on one cheap D/A converter (OVP resolution can be quite coarse) and one comparator, connected to linear regulator directly, or to an interrupt pin on MCU. With interrupt on MCU you could get microseconds reaction time. ... D/A could have been PWM for all the practical purposes.
On some old Keysight PSU, they used single audio D/A converter, multiplexed to 4 S/H circuits (that served as filters too) to serve set voltage and current and OVP/OVC protection...
Many ways to do it. But even with hardware being what it is, in software you could prevent 90% of problems they don't do now...
Regards
Sinisa
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....
I blow up my initial budget, but i think it is good invested money and that i will glad my choice.
I will try to negotiate some discount from seller.
Thanks a lot again for your advice and given information.
I am still impressed by the forum's maturity, the lack of unpleasant remarks, and quality of discussion. Very glad to found it ! :-+
I'm sure you will be happy with your decision.
As far as maturity goes, let's say we got lucky this time... >:D
Jokes aside, sometimes it gets heated here, but in general, better than anywhere else.. I thank Dave for setting some rules so things can stay that way.
But, yes, some very nice people and some very knowledgeable people here, sometimes even both at the same time ... :-DD
à la prochaine , stay safe..
Sinisa
EDIT: P.S.
Only way to work around that latency is being careful. You could make simple hardware crowbar circuit and connect it externally parallel to the load, if what you're doing is really critical. In my opinion you should do it anyway if your DUT is very sensitive, just to have redundant circuit ... Also with low voltage boards, you should work from low voltage channel for starters, so overvoltage is max 5V not max 33V..
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...
Reaction time could have been in microseconds, if they didn't save on one cheap D/A converter (OVP resolution can be quite coarse) and one comparator, connected to linear regulator directly, or to an interrupt pin on MCU. With interrupt on MCU you could get microseconds reaction time. ... D/A could have been PWM for all the practical purposes.
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It should still be possible for Rigol to correct that by means of a firmware update if they really want to. The processor they used in the individual channel circuitry appears to be an ADuC7060 (https://www.analog.com/media/en/technical-documentation/data-sheets/ADuC7060_7061.pdf) with a maximum ADC conversion rate of 8kHz. Considering the performance of this processor of round about 10MIPS, it should be possible to react to overvoltage / overcurrent conditions within round about 130~150µs, probably fast enough to stay within the ramp-up event, thus not delivering any substrantial overvoltage sufficient to kill the DUT.
If this will actually happen is written on another page. It probably depends on how many customers will complain to them... So far, I'm just careful when entering the parameters not to err on the high side. The biggest problem (yes, I know from experience ::)) is actually the risk of reversing the polarity to a DUT or on a multiple-voltage setup, just confusing the channels, and then the best overvoltage protection won't help you!
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Reaction time could have been in microseconds, if they didn't save on one cheap D/A converter (OVP resolution can be quite coarse) and one comparator, connected to linear regulator directly, or to an interrupt pin on MCU. With interrupt on MCU you could get microseconds reaction time. ... D/A could have been PWM for all the practical purposes.
...
It should still be possible for Rigol to correct that by means of a firmware update if they really want to. The processor they used in the individual channel circuitry appears to be an ADuC7060 (https://www.analog.com/media/en/technical-documentation/data-sheets/ADuC7060_7061.pdf) with a maximum ADC conversion rate of 8kHz. Considering the performance of this processor of round about 10MIPS, it should be possible to react to overvoltage / overcurrent conditions within round about 130~150µs, probably fast enough to stay within the ramp-up event, thus not delivering any substrantial overvoltage sufficient to kill the DUT.
If this will actually happen is written on another page. It probably depends on how many customers will complain to them... So far, I'm just careful when entering the parameters not to err on the high side. The biggest problem (yes, I know from experience ::)) is actually the risk of reversing the polarity to a DUT or on a multiple-voltage setup, just confusing the channels, and then the best overvoltage protection won't help you!
I agree! To all, including reversing polarity... :palm: Ask me how I know.... :-BROKE
Take care Tom.