I know this is a commonly asked question but most of the answers I got are more than 5 years ago.
So basically, my friend found a ATX power supply and was going to give it to me. Since I already have a power supply for my computer, I planned on turning it into an overpowered bench power supply. It has 1x 3V3, 1x 5V, 2x 12V and a -12V. It also have a writing in the corner v2.2. [That's what he said.]
Also, I was going to turn the 2nd 12V into a power source for my to-be-created DC soldering station. So it's going to be a DIY bench power supply + soldering station hybrid.
Can anyone tell me anything about the minimum load for each rail?
I found something on the internet that it needs 10ohms on the 5V. So that's 500mA. I also found that it needs 2-4A on the 5V rail as the minimum load. Almost all threads are contradicting each other so I felt I need to ask a new question.
Best Answer
Over 20yrs ago a PC PSU would not perform as well as today and required some preload up to 10 % when good performance was expected with no load.
Today I have not had this experience and can easily operate all outputs with no load. So,there is no minimum load spec. The Intel spec is for no damage to the unit but shutdown is permitted.
Since the most common design uses a multiwinding shared transformer to define the output voltage ratios , feedback on only needed on the primary output. That used to be 5V out for current but now is 12V with options for a secondary 12V with independent regulation for less load crosstalk between peripherals and GPU.
Your performance may vary and every design may be different. I might test it then add 5% preload if it shuts down after a transient load on your project,