COMPUTER POWER SUPPLY ?

Power supply unit (computer)

 

 

From Wikipedia, the free encyclopedia

An ATX power supply unit with top cover removed

A power sup­ply unit (or PSU) con­verts mains AC to low-volt­age reg­u­lated DC power for the in­ter­nal com­po­nents of a com­puter. Mod­ern per­sonal com­put­ers uni­ver­sally use switched-mode power sup­plies. Some power sup­plies have a man­ual switch for se­lect­ing input volt­age, while oth­ers au­to­mat­i­cally adapt to the mains volt­age.

Most mod­ern desk­top per­sonal com­puter power sup­plies con­form to the ATX spec­i­fi­ca­tion, which in­cludes form fac­tor and volt­age tol­er­ances. While an ATX power sup­ply is con­nected to the mains sup­ply, it al­ways pro­vides a 5 Volt standby (5VSB) volt­age so that the standby func­tions on the com­puter and cer­tain pe­riph­er­als are pow­ered. ATX power sup­plies are turned on and off by a sig­nal from the moth­er­board. They also pro­vide a sig­nal to the moth­er­board to in­di­cate when the DC volt­ages are in spec, so that the com­puter is able to safely power up and boot. The most re­cent ATX PSU stan­dard is ver­sion 2.31 as of mid-2008.