Following the well known instructions I've built the PSU from a spare 500W ATX. I've used 10 Ohm resistor for artificial load on 5V line.
When I connect 1A load to 12V line, the ATX shuts off. I need to wait a bit and restart it.
This only happens if I connect the large load rapidly (i.e. turn on the LED driver with around 1A load). When gradually increasing the load, I can reach 2.5A with no issues.
Say I connect a 0.5A load and it works. Let it run for a few minutes, then load it with 1A, let it run again and eventually I can have my 2.5A LED light connected. I can turn off the ATX and turn it on again and it still works.
If I however keep it off for a few minutes and turn on again, connecting anything above ~0.8A causes immediate shutdown.
According to the sticker, 12V lines are rated 15A / 17A. I've tried increasing the load using 3.2 Ohm (10R and 4R7 in parallel) but that didn't help.
Is the ATX faulty or have I overlooked something? The only possible explanation that came to my mind is that the LEDs driver I'm using has some extreme power peak when warming up. So maybe it's not about turning off the PSU but about turning off the LED driver... will test it against some 12V motor