2.7 Power Supply

Figure: Power Supply Box of Desktop Computer

Computer is an electronic device which operates by using current. Computer is supplied 230 volt AC current which is converted to 110 volt DC current. Various components of computer such as Hard-Disk, CD-ROM, USB port, serial port, keyboard, mouse
etc. needs current to operate. The computer has a power supply box known as SMPS (Switched Mode Power Supply) at the back-side of the casing.

230v AC current is supplied to the SMPS which again convert it to 110v DC current. The converted DC current is supplied to the motherboard and other components through different color wires. Different color wires are bunched to power connector. 4 pin power connector with Yellow, Black and Red wire is used to supply power to Hard-Disk, CD-ROM and Floppy disk drives. For old motherboard 12 pin power connector is used whereas new motherboards have 20, 20+4, 24+4 pin power connector.