Definition of Power Supply
A power supply unit (PSU)
converts mains AC to low-voltage
regulated DC power for the
internal components of a
computer.
Power Supply Types
AT = Advance Technology
ATX = Advance Technology eXtended
How a power supply works
•The power supply converts AC from your
homes outlet into DC which your computer
needs to run.
•It adjust the supplied voltage to the levels
needed
•It filters the voltages
•Prevents any damaging power from
reaching or take effect at the output.
How the computer uses the
voltages
•In the power supply the computer
uses the 3.3 voltage and 5 volt to
run the digital circuits.
•The 12 volt is used to run motors
like in the disk drive and the fan to
keep the computer from over
heating.
ATX Power Supply
• ATX has a
20-pin
connector for
mainboard
power
•+12, -12, +5,
-5, 3.3V
output
•The on/off
switch of
ATX units is
controlled
through the
motherboard
AT Power Supply
•There are 2- 6 pin connectors that supply
power to the motherboard.
•There are 4 voltages that AT supplies +5,
-5 +12, -12.
AT Power connector
Difference between AT & ATX
Power Supply
ATX 2.0
•20 pin connectors
like the ATX
power supply
•ATX 2.0 has a 24
pin connector
How its converted into DC
Different Components of Power Supply
Different Components of Power Supply
•Y type capacitor
Which is connected between live and
neutral ground and lead electrical shock
to ground.
Different Components of Power Supply
•Manual power
switch that is on
the AT power
supply models
Different Components of Power Supply
•Common mode
choke coils are
used to suppress
common mode
noise
Different Components of Power Supply
•Primary
electrolytic
capacitor
controls the
input current
of the power
supply and
changes the
phase shift
between the
current and
voltage
Power Supply Brands
•Samsung
•Silen x
•Cool master
•Topower
•Enhance
•Hiper
•Corsair
Power supply Pricing
•Power supplies sell for as low as 45 dollars
up to 500 dollars for the higher end kind
that put out more voltage and have more
protection from damage.