Click the schematic diagram to enlarge. An interesting project to create a variable output benchtop power supply from an atx psu other good instructables on psu modification.

Dc Dc Atx Psus
Atx power supply wiring diagram. Note that most schematics circulating on the internet depict old style psu with bipolar transistors and without pfc. This is a conceptual circuit diagram of the power train of a typical atx computer power supply unit. Similar circuit is used in the most power supplies with output power about 200w. This power supply circuit uses chip tl494. Device use push pull transistor circuit with regulation of output. This schematic does not show the control circuitry thats why you see all mosfet gates and transistor bases are open.
The diagram below shows a partial schematic of a 450 watt atx power supply. Excellent diagrams here and good ideas about fuse use a very slick supply built to allow psus to be easily exchanged this project is my personal favorite this hacker has created and sells an adapter to. This power supply has atx design and 200w performance. In addition to the old at standard atx 20 has one extra voltage line available 33v a connector chain lined to the single 20 pin and a power on wire that allows software to turn off the psu. The following picture shows the 300w atx power supply schematic diagrams. Audio battery buick cadillac chevrolet cigar lighter circuit circuit diagram circuit diagrams electrical circuit electrical schematic electrical system ford fuel pump fuel pump relay fuse block fuse box fuse holder fuse layout.
Atx specification includes not only power supply unit but also interface to case and motherboard. Its construction is typical for a modern computer psu with mosfet switches and active power factor correction pfc. I was drawed diagram when i repaired this power supply.