pc psu

i want circuit diagram for this psu and general working principle

You need to know that they never leak their schematic diagram because these are professional manufacturer and they work for benefit. You may find something similar (hardly) SMPS diagrams in internet instead.

there are many atx power supply schematics on the internet although it would be impossible to find the schematic of a generic Chinese psu.

If you just want to use it as a power supply, here are some pinouts.
**broken link removed**
It needs a load so put a 10 ohm 10W resistor between any +5 red wire and ground.

Maybe this will help.

ClydeCrashKop said:

It needs a load so put a 10 ohm 10W resistor between any +5 red wire and ground.

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Did you mean that the computer ATX power supply should not be turn ON without load?

Willen said:

Did you mean that the computer ATX power supply should not be turn ON without load?

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You can turn them ON without load, but the Power Supply may not Switch On without a minimum load on the 5 Volt output.

Ramussons said:

You can turn them ON without load, but the Power Supply may not Switch On without a minimum load on the 5 Volt output.

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If the fact applies to all general PSU, it's very nice info to me. I have replaced a shorted diode near a transformer in a computer PSU and shorted (once) the start wires to turn it ON, but not responding. I will try again with load resistor once.

Ramussons said:

You can turn them ON without load, but the Power Supply may not Switch On without a minimum load on the 5 Volt output.

Click to expand...

Should have been more precise in my statement

"........... the Power Supply may Switch ON for a Second or Two before Shutting Down."

It needs to switch ON before the electronics realizes that the 5 Volt Bus is not loaded and shuts down.

There are loads of web pages that describe the different sections of ATx supplies, while each brand may be different in actual design they all tend to have isolated section's. For example most have the big Caps for smoothing the input etc, depending on design many have a pwm chip (actually google for altering ATX by pwm chip). I was dabbling with a couple and found that once you get a general idea how they are meant to work you can identify the sections, be careful though I have had a couple of large nips of them even after being powered off for weeks.
I will try and get some pages for you but I dont have my old bookmarks anymore