electronic load for PSU testing

[tony359]

Hi all,

I've always tested power supplies using high power resistors but that can be time consuming (need to put together an appropriate resistance value and make sure you're not overloading etc).

I stumbled into many electronic loads on aliexpress today. The below is just an example:

Aliexpress link

They're meant for batteries, would they work ok with power supplies? It would just be much easier to dial a trimmer than digging into a box of resistors (which then need to be connected etc).

For sound gear testing I'll stick to resistors of course

Thanks!

[spiros.p]

yes.i use one rigol for single supply psus.for multi output psu may need more electronic loads or multi chanel load to test simultaneously

[Mario875]

They work well for PSU testing if used correctly, but be careful, I have seen an instance on a power supply that was being tested from an industrial device where the load was set to 200W BEFORE the PSU was powered on, then as soon as the PSU turned on the load was immediately asking for 200W as the output voltage is still rising (200W @ 1V = 200A!!) and it essentially over loaded the PSU resulting in catastrophic failure, a big bang and black ash.

Admittedly this PSU on question has a startup circuit which failed dead short and caused the failure, not all PSUs are designed the same way, but something to be aware of.

Used properly they are great, but a small mistake like setting for constant power load on a PSU that is off then turning on the PSU can cause a dangerous situation.

So as always when working with PSUs, be safe, be careful!

[tony359]

Thanks for all your thoughts.

I got that load and I like it. I made sure the mosfet was properly installed and put good thermal paste.

I've tested at max power for a while and I had no issues. It's very convenient particularly with low voltages when you want to get to high currents and you don't have a bucket of high power/low value resistors