Study of power supply used in computers

Introduction power supply is an electrical device that provides power to electronic devices and circuits most of the

electronic devices require less power dc voltage as compared to the voltage supplied to home or office this led to the

development of switching mode power supply (SMPS). This Device is responsible for the power conversion from high

voltage ac to low voltage dc.

Identifying different specifications of smps: to identify various SMPS you need to consider certain factors such as size

wattage and different connectors.

Size: power supplies are available in various sizes. Before selecting a power supply you need to select power supply of

appropriate size which can fit in your system case.

Connectors: check for the available number of power supply connectors that can provide supply to all the devices. More

number of connectors is better.

Wattage: servers and desktop computers work in power rating. Power rating is measured in terms of watts. Rating for

SMPS varies between 250w-600w.maximumPower consumption occurs at start up time of SMPS.computersHave rating

between 250w-5000w and servers have rating between 400w-600w.

SMPS from Factors: the form factor of power supply represents the size and the shape of power supply. The different

from factors of the power supply unit are the PC/XT, baby-AT style are ATX (NLX), STX and WTX form factors.

Low profile Extended: from factor is also known as slim line form factor because its cases are known as slim line cases.

The cases the main goal of this form factor is size reduction. Because of its small size and convenient rectangular shape,

LPX can put into all sorts of cases. With raiser card arrangement for expansion cards where expansion board run parallel

to the motherboard.

Advanced technology extended :The ATX sstem uses new kow profile extended (NLX) power supply.hence the ATX form

factors are also knowns as ATX form factor does not have a power outlet to connect the power cord of the monitor to

the power unit this power fan draws air form outsite the system and blow it inside the system to cool the system

Small form factor:The SFX power supply unit has two fans to cool the whole system.this additional fan is placed on

the top of the power supplyThe internal fan of the SFX power supply its thermally speed controlled. The output of SFX

power supply unit is 90w and is used on smaller systems that do not require a lot of power.

Different connectors of SMPS: provides current to the motherboard,hard disk drive,and various other components of

a system using the power connectors.power connector is an electrical connector used to carry dc voltages there are 5

types of connectors.

ATX power connector: this is a 20pin connectors with 6 types of voltages Coming out of it. The ATX style power

connectors are for the ATX/NLX power supply.ATX/NLX from factors use the ATX style power of the is connectors.this

style has a single 20-pin connectors.

24 pin SMPS Connector:the 24 pin SMPS connectors is built with ATX style Of power connectors. This connector is

used to provide power supply to the motherboard. The 24pin Smps connector has 4 additional pins which Carry a

different voltage level as compared to 20 pin connect

Standard peripheral power connectors (molex): the disk drive power connectors use 4wire connectors which are

commonly called molex Connectors.the hard disk drice, cd/DVD drives use molex connector

SATA power connectors: the sata standard specifies a power connectors which is different from those used by PATA

drives and many other computer components molex connector.it is a 15-pin connector. The large number of pins are

used to supply three different voltages 3.3v,5v.

PCI-E 6 Pin connector: PCI-e cable is used to provide extra 12 volt power to PCI ecpress expansion cards. PCI express

motherboard slots can provide amaximum of 75 walts.