Built a PC power supply basically quite simple. It consists of a housing made of metal. A Euro unit connector is for connecting to the socket, and there is a power switch. The PC power supply has at least one fan. There are power supply that work with multiple fans.
With these DC voltages are now able to be supplied to individual lines and power plug to the components and the PCB. There are several important lines, which are color coded. The power connector has 20 or 24 poles and distributes the voltage to 3.3, 5 and 12 volts at the interfaces. Here are the lines for mass, power-OK, PS-ON, 5VSB standby power, on and off switch and the Sense Amp This is important to compensate for voltage fluctuations and losses in the PC power supply.
Power to the hard disk is distributed through a 4-pin PATA connector. It has 15 connections, ground line,12 volt and 5 volt lines. Alternatively, it is a SATA drive, which also works with the 3.3 volt, the board requires a 20 or 24 pin socket for the ATAX connector and a 4 or 8 pin socket. There are components that require more power. These include graphics cards and CPU. These component will be provided with an additional power line. For graphics card or CPU would be 6 or 8 pole 12 volt channel of the PC power supply.