DC Power Supply Recommendations

[Day Radebaugh]

I'm a newbie, and my main hobby is repairing and restoring old trucks.  I frequently need a DC power supply that provides battery voltage (+12V DC) to test fuel pumps, fans and other such accessories.  I had an old battery charger that had an Activate setting that used to do the job but that no longer works.

So my needs are fairly simple.  I looked on Amazon for DC power supplies, but was unsure of the quality of their offerings.  I'd like to get a unit that would supply 0-20V,  maybe 10A, and had a voltage and current read out. 

Would you have any recommendations for a used HP or other name brand power supply that was simple and reliable?  Perhaps a retailer that restores and sells such units?  My preference is to look for a used unit from a reputable brand rather than take a chance on something new of questionable quality.

Thanks

[BillyO]

This is a good quality supply at a decent price, but it is not adjustable:

https://www.amazon.ca/Pyramid-Bench-Power-Supply-Converter/dp/B07KMLNLWQ


What is you budget?

[TimFox]

Here is a typical listing from a used-equipment dealer for an old-school Agilent/HP 6264 0-20 V, 20 A DC supply, in "reconditioned" condition for $295.
https://accusrc.com/product-Agilent-HP-6264B-5041
The old-fashioned units tend to be about this size (roughly 5 x 19 x 19 inch).

[Benta]

Another idea might be to look for used CB/radio amateur power supplies.
There must be a ton of them out there, the CB/RA species is dying out.
They're normally 13.2 V units with lots of amps for high transmitter power.

[AG6QR]

A bench power supply unit intended for an electronics lab will typically either have a small current capacity or will be quite expensive.  It will likely have more precise regulation than is needed for testing fuel pumps, fans, and other such things.

Ham radio transceivers typically are designed to work with DC power from a vehicle, at 20-30 amps or so.  You might consider supplies intended for that market.  Many of them have a fixed 13.8VDC output.  Some are adjustable.  I'm a ham radio operator. I own a Powerwerx SS-30DV, and I know several other people in my ham radio club that use these.  They work well, offering a fixed voltage output (actually adjustable if you're willing to take the case apart and tweak a pot) at up to 25A continuous, or 30A for brief periods.  For an extra $30 or so, they offer a similar unit with voltage and current meters, and output voltage adjustable between 5-16VDC.  I know one person with the adjustable model, and he's happy with it.

https://powerwerx.com/variable-power-supply-digital-meters-30amp
https://powerwerx.com/ss30dv-desktop-dc-power-supply-powerpole

[Day Radebaugh]

I believe that a fixed battery-equivalent voltage (~13.8V) unit would be satisfactory for what I'm doing. I now understand the tradeoffs here: an electronics lab type unit may not be what I need for testing vehicle accessories.

Your comments have certainly educated me, and I appreciate the suggestions.   

[Benta]

Many of them have a fixed 13.8VDC output.

I stand corrected. The 13.2 V was off the top of my head. Thanks.

[Gregg]

I suggest a Gophert power supply because you can limit the voltage / current as necessary; they are reasonably priced and available in many configurations.  https://www.aliexpress.us/item/2251801616690893.html
VoltLog made a video about them

[Benta]

5 A is somewhat low for automotive use. It'll drive one low-beam bulb, that's all.

[Jwillis]

Volteq  formerly Mastech has some that will provide the power you need. Also being out of the United States you might save on shipping as well. They're not fancy but the HY series power supplies have been around for ages and have a pretty decent reputation of reliability. Prices aren't bad either. 
https://www.volteq.com/

[Day Radebaugh]

This one looks pretty good: https://www.volteq.com/volteq-power-supply-hy3010ex-30v-10a-over-voltage-over-current-protection.html

Any idea where it is built?

Thanks

[Jwillis]

This one looks pretty good: https://www.volteq.com/volteq-power-supply-hy3010ex-30v-10a-over-voltage-over-current-protection.html

Any idea where it is built?

Thanks

Best bet? China. My Mastech doesn't have an origin either.

[Day Radebaugh]

Does anyone have any experience with Powermax charger/power supplies? https://powermaxconverters.com/product/pm3-12v-series/

Thanks

[Jwillis]

Does anyone have any experience with Powermax charger/power supplies? https://powermaxconverters.com/product/pm3-12v-series/

Thanks

They're OK .Well built. Just need to remember that for power supply mode on the 12V model, the adjustable voltage is only between 13V and 16V and there is no current limiting control .

[Day Radebaugh]

Thanks for the information.  This might meet my needs as a battery replacement, and I assume that the devices I'm powering will draw only as much current as they need.

[coromonadalix]

you have pyramid psu's,  not the best ones,  sometimes needs recap on the mains

but i choose them to hack them into variables ones from 1.2volts to the highets possible, they are built around lm723

and you find their schematics pretty easily

i did tweak one into a variable current too


some astron too

[Jwillis]

Thanks for the information.  This might meet my needs as a battery replacement, and I assume that the devices I'm powering will draw only as much current as they need.

That is true that a device(load) will only "draw" as much current that it requires. But lets assume for a moment that you need to test a device that keeps blowing fuses. And you want to find out why. By connecting that device to a supply that has no current control you may cause more damage to that device than intended. With current limiting  control you can diagnose a problem easier without destructive consequences.
Just a thought.

[Day Radebaugh]

I understand.  Thanks for the suggestion.

[Day Radebaugh]

I'm an old-timer, and an old school type.  I tend to think that things might have been built better years ago than they are now.  So this caught my eye:

https://accusrc.com/product-Agilent-HP-6286A-5156

The specs and size pretty much meet my needs.  Any suggestions/thoughts about such a unit?  Would I have to worry about caps being too old and failing?

Thanks

[TimFox]

I have used other supplies in that -hp- series (originally Harrison), and they are good classic designs.
The one I mentioned near the beginning of this thread is twice the power, and only slightly more expensive, but much larger.
(The one you mention is out of stock, but there are plenty of this generation out there.)

[Day Radebaugh]

Right you are about the larger one, but I think I just don't have room for it.  What about the age of these units?  Do you have a used dealer you can recommend?  And as you say, there are plenty of them out there.

Thanks