power supply

The power supply unit of system mostly found in the top corner of the system case accepts the AC ( Alternating current ) from the power socket in the wall. It then converts the AC to DC ( Direct current ) for the system. Now a days power supplies are available in the range of 250W to 400W.

Types of power supply:
A power supply is a system which provides power to the circuit or the devices connected to it. Power supply converts the AC to DC voltage. Maney units of the computerrequir DC power. The two types of power supplies are Linear power supply and switch mode power supply.

Linear Power Supply-
Transforms incoming voltage to a lower voltage using transformers. A diode circuit is used to rectify the AC voltage to pulsating DC. the
capacitor filter is then used to provide DC voltage with low ripples. Finally,linear regulator is used to reduce the voltage to a desired level. Linear power supply is bulky but has very low noise.
Switch Mode Power Supply -
Uses high switching frequency. It is compact and can deliver very high power. It is used as DC to DC converter in which power switches, power connectors and power supply fan.

Power Connectors:
The power supply unit provides current to the motherboard, hard disk drive, floppy disk drive and various other components of a system using the power connectors carrying small amount of power are called signal connectors. There are 5 types of connectors.

1. AT power connectors
2. ATX power connectors
3. Standard peripheral power connectors ( Molex )
4. Floppy Drive power connectors ( Mini/Berg )
5. 2/3 Pin Mini plug type connectors

AT Power connectors -

There are two 6 wire connectors named P8 and P9 which are to be connected to the motherboard with black wires inside. The PC/XT, AT, Baby AT and LPX form factors of the power supply use a pair of 6 wire connectors, called as AT style connectors to connect the power supply to the motherboard.

ATX Power Connector -

This is a 20 pin connector with 6 types of voltage coming out of it. The ATX Style power connectors for the ATX/NLX from factors use the ATX Style power connectors. This style has a single 20-pin connector.

Standard peripheral power connectors ( Molex ) -

The disk drive power connectors use 4 wire connectors. The 4 wire connectors are available in large and small size connectors. The hard disk drive, CD/DVD drives use larger size connectors, commonly called as Molex.

Floppy Drive Power Connectors ( Mini/Berg ) -
The 3.5-inch floppy disk drive use smaller size connectors, called as mini-plug.