I’d like a variable voltage/current power supply for testing drivers/emitters. ~36V, ~10A would be great, but depending on price, I might go as low as 20V, 5A.
I’ve been doing some searching (google and here) but I’d like to hear from some members here.
thanks!
For the money, this one is hard to beat. I’ve got one at home, and it’s perfect for this kind of stuff.
It’s good for 0-60V at 5A or 0-30V at 10A
PPtk
If you want to go super budget, a Accucel 6 can be effectively used to test LEDs. You can also set the drive current, but it is certainly finicky as it is simply using it on the LiFePo4 setting. ;)
Haha, neat use, yes set to LiFePo4, 3.3V, adjust max output charge amperage.
But you need a PSU to power the Accucel 6.
What you described is going to cost you hundreds of $ if you’re going to buy it as a final product.
You could build a variable output PSU from a power source of your choice, like some meanwell, or an old ATX power supply, etc. only depends on your needs of voltage and amperage. The regulator will cost you something since you want really really high amperages of bariable output and the PSUs can give you high outputs of preset voltages.
3.3V, 28A, 5V 30A, 12V 16A is my old poor 350W ATX PSU with added variable output and meters for V and A, 1.2-10.6V 1.5A max. It depends what you build as the regulator.
Lab PSUs are expensive but you can find many instructables around the net to make one cheaply from parts reusing some sort of power source.
5A is doable with LM338.
All you need is a variable resistor to adjust the output, a fixed resitor, 2 diodes, 2 filtering capacitors all worth maybe $2. The LM 338 will cost a little but it’s below $10 I think. And a heatsink for it, just find one around the house.
And a power source to feed the LM338 enough power. Some small box for it and connectors. Yes it does add up with all the little things but it’s still nowhere near the price of a professional lab PSU. And you can build it the way you want it with the features you want quite easily.
I used LM317 since the variable voltage at 1.5A is enough for me and costs below $0.5.
You can use another chip like that to make a current limiter so you can have both voltage limit and current limit.
Maybe there are some other options, I used the LM317 so far few times it is cheap and it worked for what I needed it for.
Power source you can get from ebay or other shops, like a professional power supply with the voltages and amperage you want, it costs but not as much as a lab PSU.
Or reuse various power supplies from electronics, like server powersupplies, desktop computer powersupplies, etc.
I have a small PSU out of an old Cisco router, gives me 12V and 5V, and –12V but dunno what amperage on these. Just look around.
Laser printer could have a decent PSU in it. etc.
I use one of these - 15V/20A
http://www.valuetronics.com/detail/Used-sorensen-xantrex-elgar-ametek-hpd15-20.cfm
I got mine for $50 when a local electronics company was downsizing and selling off surplus equipment. Keep an eye on eBay and other places, you might come across one.
Previously I used a modified 12V/20A ham radio linear power supply, I added a pot to the front to set the output voltage from about 2V to 16V. Moved up to the Xantrex because I wanted an adjustable current limit.
HP6038A… one can occasionally snag one for cheap on Ebay. Does 60V/10A up to 200 watts. Avoid the Option 1 version… it can only be computer controlled. Avoid the a-holes trying to get $500-$1500 for them.
Yep, if you can find them cheap, they’re great supplies. We’ve got dozens of them laying around and they all have been in service for years and years. I haven’t seen one go cheaply in a long time though…
PPtk
I bought one for around $50. The guy said he had three more if I wanted them… well, duh!!!
The HP 6034A is petty much the same thing in a horizontal form factor.
If you can deal with HPIB programming and don’t need the front panel, the Option 001 units are much more available for real cheap.
Hmm, I was hoping <$100 but figuring ~$150.
I like the one PPTK recommended - I might just have to suck it up and get it, because if I compromise on features I’ll end up spending more by upgrading.
Any comments on circuit specialists customer service? I see there is a 12 month warranty on the CSI3005xiii…
If you are unable to wait for a good ebay deal, one of the better made, budget power supplies matching the specs that PPTK recommended is this one by Mastech.
It is similar in specs to the one PPTK recommended. I use it for my electronics projects. It is well made. The reseller has a good history of technical support. There are many people over at eevblog who consider it a very good power supply for the price.
Apart from the build quality, the one nice feature of this power supply, compared to a lot of similar looking ones, is that it has 10-turn pots for voltage control.
I like analog power supplies over switching supplies. I'm using an Astron RS-20A. (16 amps continuous) It's internally adjustable from about 11 to 15 volts. It's way more than I need for use with my hobby chargers.
For projects that require more range and adjustable current limit, I use a Tenma 72-7295 0 to 40 volt, 5 amp switching PS
Mastech. That looks really good I have to say for the price 
Just noticed that you are in Czech. Shipping charge for a 20-25lb equipment from the US might be ugly. Perhaps you are better off buying locally?
I assume the mastech linked can be paralleled, like the CSI can?
Yes, parallel for doubling current and series for doubling voltage.