The document discusses power supplies used in computers. It begins by introducing switching mode power supplies (SMPS) which convert high voltage AC to low voltage DC required by electronic devices. It then identifies various specifications to consider when selecting an SMPS, including size, wattage, connectors, and form factor. Different SMPS connectors are discussed, including ATX, 24-pin, Molex, SATA, and PCI-E connectors which provide power to various computer components from the SMPS.

1. Study of power supply used in computers
Introduction power supply is an electrical devicethatprovides power to electronic devices and circuitsmostof the
electronic devices require less power dc voltage as compared to the voltage supplied to home or office this led to the
development of switchingmode power supply (SMPS). This Device is responsiblefor 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 areavailablein various sizes.Before selectinga power supply you need to select power supply of
appropriatesizewhich can fitin your system case.
Connectors: check for the availablenumber of power supply connectors that can provide supply to all thedevices. More
number of connectors is better.
Wattage: servers and desktop computers work in power rating. Power ratingis measured in terms of watts. Rating for
SMPS varies between 250w-600w.maximumPower consumption occurs atstartup time of SMPS.computersHave rating
between 250w-5000wand servers have ratingbetween 400w-600w.
SMPS from Factors: the form factor of power supply represents the sizeand the shape of power supply.The different
from factors of the power supply unitare the PC/XT, baby-AT style are ATX (NLX), STX and WTX form factors.
Low profile Extended: from factor is also known as slimlineformfactor becauseits cases areknown as slimlinecases.
The cases the main goal of this form factor is size reduction.Because of its small sizeand convenient rectangular shape,
LPX can put into all sorts of cases.With raiser card arrangement for expansion cards whereexpansion board run parallel
to the motherboard.
Advanced technology extended :The ATX sstem uses new kow profileextended (NLX) power supply.hencethe ATX form
factors arealso 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 formoutsite the system and blowit insidethe system to cool the system

2. Small form factor:The SFX power supply unithas two fans to cool the whole system.this additional fan is placed on
the top of the power supplyTheinternal fan of the SFX power supply its thermally speed controlled.The output of SFX
power supply unitis 90wand is used on smaller systems thatdo 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 usingthe 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 usethe ATX stylepower of the is connectors.this
stylehas a single20-pin connectors.
24 pin SMPS Connector:the 24 pin SMPS connectors is builtwith ATX style Of power connectors. This connector is
used to provide power supply to the motherboard. The 24pin Smps connector has 4 additional pinswhich Carry a
different voltage level as compared to 20 pin connect
Standard peripheral power connectors (molex): the disk drivepower connectors use 4wire connectors which are
commonly called molex Connectors.the hard disk drice,cd/DVD drives use molex connector

3. 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 largenumber of pins are
used to supply three different voltages 3.3v,5v.
PCI-E 6 Pin connector: PCI-e cableis used to provideextra 12 voltpower to PCI ecpress expansion cards.PCI express
motherboard slots can provideamaximumof 75 walts.