Hi, before i start i just want to
since unmodified ATX psu pretty much sucks as a lab supply, I decided to make it into one. Internet is full of "tutorials" how to do such thing but all of them are just useless bull**it because they only show you how to put a linear regulator or whatever into it. So i made one on my own by disconnecting pins 1 and 2 of TL494 and connecting them so pin 2 is around 1,5V (voltage divider from VREF on tl494) and pin 1 is connected to gnd with one resistor and to 12v with potentiometer. It works really great but i have one problem - protections. On old crappy supply i had i just desoldered 8 pin protection chip and grounded some pins but then it lost short circuit protection and i "accidentaly" fried it (love that burnt semiconductor smell). Now i got myself some really nice psu - lots of imput filtering, high current everything(transistors, rectifiers,...), lots of output filtering as well, good quality output caps, etc. It has protections probably somehow made through lm339. I wouldnt mind them - still works from 1,5 to 17 volts with high currents but i would like to remove all unnecesary coils, caps, etc from other outputs since i dont plan to use them. Problem is that i cant. Even when i removed output cap from -12 volts the damn thing refused to start. I guess I can just remove all "unneeded" circuitry but i really want short circuit protection on this thing.
Is there anyone who would like to help me with this?
Some photos: http://imgur.com/a/rZbAZ
since unmodified ATX psu pretty much sucks as a lab supply, I decided to make it into one. Internet is full of "tutorials" how to do such thing but all of them are just useless bull**it because they only show you how to put a linear regulator or whatever into it. So i made one on my own by disconnecting pins 1 and 2 of TL494 and connecting them so pin 2 is around 1,5V (voltage divider from VREF on tl494) and pin 1 is connected to gnd with one resistor and to 12v with potentiometer. It works really great but i have one problem - protections. On old crappy supply i had i just desoldered 8 pin protection chip and grounded some pins but then it lost short circuit protection and i "accidentaly" fried it (love that burnt semiconductor smell). Now i got myself some really nice psu - lots of imput filtering, high current everything(transistors, rectifiers,...), lots of output filtering as well, good quality output caps, etc. It has protections probably somehow made through lm339. I wouldnt mind them - still works from 1,5 to 17 volts with high currents but i would like to remove all unnecesary coils, caps, etc from other outputs since i dont plan to use them. Problem is that i cant. Even when i removed output cap from -12 volts the damn thing refused to start. I guess I can just remove all "unneeded" circuitry but i really want short circuit protection on this thing.
Is there anyone who would like to help me with this?
Some photos: http://imgur.com/a/rZbAZ
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