Recommendations for a 20A or higher bench PSU, for under $150 shipped?

My current bench PSU is great, but it maxes out at 5A.

It's time to upgrade to (or add to my collection) a bench PSU capable of higher currents. 20A is a target, but it has no specific significance beyond being the minimum current I'd want to be able to hit to make the investment/upgrade worth it to me. 25A or 50A would be just fine too

My budget is $150, shipped, and shipping will be to Canada, which sometimes narrows the options. I recognize that this budget is asking a lot, but there are a couple options I've come across so far. The leader so far is this:

http://pages.ebay.com/link/?nav=item.view&id=271588660952&alt=web

Does anyone have any suggestions?

Go used, man.

1 16volt DC Bench TOP Power Supply | eBay

EM SCR 20 7 5 60 0196 OV Power Supply Electronic Measurements SCR 600 | eBay

EM SCR 20 25 0196 OV Power Supply Electronic Measurements SCR 600 | eBay

RHD, the power supply you gave the link to does not appear to have current limiting, do you want CC control? For those looking for a relatively inexpensive 10 amp unit with CC control: http://www.ebay.com/itm/Bench-Power...table-Current-Limiting-CSI3010X-/381030707939

Here's a 20 amp one for not too bad a price but it's a switching supply, better to use a linear, me thinks: http://www.ebay.com/itm/MASTECH-POWER-SUPPLY-HY3020E-0-30V-20A-Switching-Power-Supply-/161454705693

Edit: Oh, look what I found, 20A linear but made in China, doesn't necessarily mean it's bad though but I'm not familiar with this model either http://www.ebay.com/itm/ZHAOXIN-RXN...ABLE-DC-POWER-SUPPLY-220V-INPUT-/161150126337

If you want a quality lab power supply with adjustable current keep your eye out for one made by Xantrex, or Sorensen for their older versions which are often much less expensive.

Cyparagon said:

Go used, man.

1 16volt DC Bench TOP Power Supply | eBay

EM SCR 20 7 5 60 0196 OV Power Supply Electronic Measurements SCR 600 | eBay

EM SCR 20 25 0196 OV Power Supply Electronic Measurements SCR 600 | eBay

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That's a good thought. If I could find the right used unit, I'd rather spend the same amount of money and get a better (albeit used) unit.

Those may not be exactly the right ones though. The first comes to about $180 shipped (to Canada) and the latter two are untested. I would also prefer a digital display.

Laser Project said:

RHD, the power supply you gave the link to does not appear to have current limiting, do you want CC control? For those looking for a relatively inexpensive 10 amp unit with CC control: Bench Power Supply 0 30 Volt 0 10 Amp w Adjustable Current Limiting CSI3010X | eBay

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Yep, it does both. My understanding is that you set it to CV or CC.

The one you linked is $200 and only 10A, so it doesn't really fit my needs.

rhd said:

That's a good thought. If I could find the right used unit, I'd rather spend the same amount of money and get a better (albeit used) unit.

Those may not be exactly the right ones though. The first comes to about $180 shipped (to Canada) and the latter two are untested. I would also prefer a digital display.

Click to expand...

The one in the first link is good, even if it is a bit out of your budget. I got a similar unit for a similar price. sub $150 really limits your options in Canada.

Aha, I see the CC on it now, missed it before. I like it for the money, only draw back is it is a switching power supply, they can be noisy but then again, I have one made by Xantrax which isn't.

I found a 20A Cinese Linear: Zhaoxin RXN 1520D 0 15V 0 20A Linear Adjustable DC Power Supply 220V Input | eBay

Laser Project said:

Aha, I see the CC on it now, missed it before. I like it for the money, only draw back is it is a switching power supply, they can be noisy but then again, I have one made by Xantrax which isn't.

I found a 20A Cinese Linear: Zhaoxin RXN 1520D 0 15V 0 20A Linear Adjustable DC Power Supply 220V Input | eBay

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Will not ship to Canada.

Also, it's 220V, not 110V.

I too have a 5A max bench supply, for my variable supply. I've got a 30A 13.8V supply from my ham radio days though for the really power hungry stuff.

Really you have to go used (luck) or expect to spend an awful lot. I haven't had any luck getting a used supply when I had the money and need for one, but you're in a much more metropolitan area than I, so perhaps you'll have better luck. Also, your budget is larger than mine was.

Something to think about is DIYing one. It isn't difficult at all. Take a cheap MOT and knock out the secondary. Wind a new secondary with some 10ga household wiring. Use a DMM and add turns until you've reached your needed maximum voltage. Rectify with a beefy monolithic bridge or high current heatsinked diode. Then just make a LM317 + Nch FET passbank. There's tons of schematics online just search "LM317 pass bank" or similar. Then apply that to a standard two regulator CV-CC layout. Add cheap chinese DVM and DCM monitors and a project box.

I wish I had time to DIY one

I'll just keep searching. Something is bound to show up in my price range.

Update: I went with Cyparagon's first suggestion.

In a moment of clarity I realized that the difference in price above my budget was the price of one relatively inexpensive diode.

I have one of those myself, works well.

I bought the PSU the Cyparagon recommended.... do these operate differently than other bench PSUs?

I can't get it to output anything. It's like none of the knobs have any impact on the voltage or current.

Sorry for the rotated video.

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That looks pretty busted to me =/

rhd said:

I bought the PSU the Cyparagon recommended.... do these operate differently than other bench PSUs?

Click to expand...

Try setting the OV knob to max before power up.

ARG said:

Try setting the OV knob to max before power up.

Click to expand...

Ya, I found a manual for how this PSU works and got it going. Hate it (the manual and the PSU)

First of all, the constant current "jumps" for the first 1.5A. IE, you get it into constant current mode, and the first 1.5A it stays at 0.0A. Then, once you've turned it a bit, it jumps to 1.5A, and adjusts smoothly from there up. I'm managed to kill about 6 CREE XML emitters. Can't imagine using this POS for laser diodes.

Maybe there's some logic to this unintuitive functionality that I just don't yet understand, but it seems like a bass ackwards way to design a PSU. My cheaper 5A PSU simply had a Fine/Coarse knob for current, and again for voltage. This appears to have a Coarse for CC, Coarse for OV, then Fine and Coarse for voltage..... no fine for current?

Plus, as best I can tell, the process they suggest in the manual (and that admittedly works) for getting it into constant current mode consists of:
1) Put OV and CC knobs to max, and voltage to min
2) Turn on PSU
3) Put CC to min
4) Put Voltage to somewhere between 3-10 Volts (but you have to guess, because the readout doesn't actually change from 0.0 at this stage)
5) Short the leads
6) *** then a bunch of steps that make no logical sense, including increasing current, while the leads are shorted, and the voltage is set..... why the f* would I do that ? ***
7) Unshort the leads and attached a load.
8) PSU now works in CC mode.

With my less expensive 5A PSU, entering CC mode involved:
1) Setting the voltage knob to max, with CC knob at min.
2) You're in constant current mode. (not really a second step!)

Here, take a look:


The constant current instructions start just below the ORANGE line.

Take a look at the step that begins at my RED mark. They're telling me to start increaseing the current regulation knob (3) while the leads are still shorted, and the voltage is set to somewhere between 3-10V.

Really? You want me to start pumping potentially substantial current / voltage through shorted leads? This is nonsense.

I'm about to toss this thing in a *****ter.

Hi if you want to regulate voltage up to 36 volt and current up to 3 amp then BangGood sell a great little digital current voltage regulater for £8.23 around $12.75 i have a couple and they work great i use my old computer power supply (500W) and you can set both the current and voltage down to point 1 volts and amps.
this is the link to them :-http://www.banggood.com/DC-LED-Digital-Controlled-Step-Down-Driver-Power-Module-p-910096.html

as long as you want less than 3 amps i doubt you could get better for the price, I use them to test diodes just with two wires with croc clips on if you even short out the cables you will not draw more current than you have set it to.
hope this helps, regards Poppy Ann.