Bench good power supply

Repair Tools
1

Hi there,

i am slowly looking to acquire a power supply, to detect in an easier way shorts when i am not able to find them on a first glance.
I have seen that one recommended by @Severence in this thread : Switch: 0.05A current draw - BQ Shorts / SYS Rails ? - diagnostic help needed - #17 by taugust
it looks great, but i am wondering if there isn’t something a bit cheaper that still would do the job. For example, i spotted that one on Amazon with Prime delivery which looks ok on spec lever, just that it doesn’t have the memory functions, but i can live without i think :slightly_smiling_face:
https://www.amazon.fr/Alimentation-Laboratoire-Ajustable-Commutation-Affichage/dp/B08MQF5966/ref=sr_1_4?__mk_fr_FR=ÅMÅŽÕÑ&crid=3G1OWIVQ0WQDD&keywords=alimentation+de+laboratoire+30V+5A&qid=1649168800&s=industrial&sprefix=alimentation+de+laboratoire+30v+5a%2Cindustrial%2C74&sr=1-4
https://www.amazon.fr/Alimentation-Laboratoire-Ajustable-Commutation-Affichage/dp/B08MQF5966/ref=sr_1_4?__mk_fr_FR=ÅMÅŽÕÑ&crid=3G1OWIVQ0WQDD&keywords=alimentation+de+laboratoire+30V+5A&qid=1649168800&s=industrial&sprefix=alimentation+de+laboratoire+30v+5a%2Cindustrial%2C74&sr=1-4
https://www.amazon.fr/Alimentation-Laboratoire-Dr-meter-Stabilisée-Commutation/dp/B08CC81KRJ/ref=sr_1_24?__mk_fr_FR=ÅMÅŽÕÑ&crid=3G1OWIVQ0WQDD&keywords=alimentation%2Bde%2Blaboratoire%2B30V%2B5A&qid=1649169087&s=industrial&sprefix=alimentation%2Bde%2Blaboratoire%2B30v%2B5a%2Cindustrial%2C74&sr=1-24&th=1
They look to have good reviews overall, but i prefer to ask before.

2

Just looking at the equivalents on UK amazon so I can read the descriptions.

The black one doesn’t mention if it’s a linear supply or a SMPS, I’d guess it’s switching given it’s size, a SMPS is fine but from our perspective the last thing we want to be second guessing is our supply, when we’re supplying or “injecting” voltage we want the supply to be as clean as humanly possible as we are hardly going to analyze what the ripple / noise is on a known good board everytime prior, with a linear this is barely a concern and just takes this concern out the picture (hope that makes sense)

The other one I couldn’t find but it seems to be under many “brand” names rebadged, afaict it’s a linear supply though the reviews for it are inconsistent across the different names.

One thing you have to watch out for with this cheaper supplies is some require you short the output before you can adjust the current limit, this is so old fashioned and I’m not sure why the PSUs even still exist as it’s a royal pain to adjust the current limit mid flow. I’m personally not a huge fan of bench PSUs which offer coarse and fine adjust dials as it’s all to easy to spin the wrong one and bam gamover

That being said, either will probably work fine, just do your research about the above points first, if the manufacturer provides a spec sheet / datasheet , great, maybe post it and I’ll give it the once over :+1:

3

Hi there, thanks for the feedback.
I finally went with the same as you, it had a good discount on one seller on Aliexpress sent from Poland, and it was barely more expensive then the others on Amazon.
I already received it, about the current limitation, is it the same with that one that i need to short the output before it is working ?

4

If you got the Korad/Tenma, nah you can adjust on the fly :+1:

5

Awesome, thanks, yes, i took the one you suggested to another member, this one :

6

Cool

I’d buy some decent heavy gauge wiring for your hookups (or temporary, strip down the wires from an old IEC cable), desolder the crocodile clip ends and solder on your decent wire as the ones these PSUs come with is junk, same with those probes, I’d toss them in the bin :slight_smile:

7

Even worse than you thought, isn’t it? :rofl:

IMG_20220408_172400
IMG_20220408_1724001920×4267 284 KB

What cable section do you think I should put? 0.75mm2 or 1.5mm2 ?

8

Haha oh yeah that’s terrible :smiley:

As large as you can, idealy silicone shroud wires for flexibility if you’ve got it but if not, no worries

I get my test hookup wire from Rapid here on big rolls, but you can get some decent silicone shrouded wire meant for Li-ion batteries pretty much anywhere