Download Brad`s Lecture on Electricity and Power Supplies

A+ certification training:
Electricity/Power Supply
Electricity for Computers
Electric Outlet in Walls: AC,110-120 Volts
Motherboard Uses DC,+3,-3,+5,-5,+12,-12
What’s the Solution?
THE POWER SUPPLY!
Changes 110-120 Volts to +-5,+-12
Changes AC to DC
Wall outlet
NEUTRAL
GROUND
HOT
SYMBOL FOR GROUND
REVIEW OF TERMS
VOLTS- PRESSURE IN A CIRCUIT
OHMS- A CONDUCTORS RESISTANCE
WATTS- POWER IN A CIRCUIT
AMPS- A CURRENTS STRENGTH
CONTINUITY- A COMPLETE CIRCUIT
THREE PARTS OF A POWER
SUPPLY
SWITCHING NETWORK
TRANSFORMER
VOLTAGE REGULATOR
SWITCHING NETWORK
CLEANS AND CONVERTS THE
“IRREGULAR” INPUT AC INTO
“REGULAR” DC
TRANSFORMER
TAKES THE “REGULAR DC 120 VOLT”
INTO SEPARATE 12 AND 5 VOLT
AC CIRCUITS
VOLTAGE REGULATOR
CONVERTS AC BACK TO DC
REGULATES VOLTAGE TO CONSTANT
LEVEL
MONITORS AMOUNT OF CURRENT
BEING USED BY COMPUTER
PARTS OF THE SWITCHING
NETWORK
 FUSES-GLASS TUBE, BURNS WHEN TOO MUCH
CURRENT FLOWS
 CAPACITORS-LOOKS LIKE BATTERIES, EVEN OUT
CURRENT FLOW
 DIODES- KEEPS CURRENT IN 1 DIRECTION
 RECTIFIERS- MADE UP OF DIODES, PRODUCE HALF
WAVE AND FULL WAVE RECTIFICATION
 TRANSISTORS-CONVERTS DC INTO “SQUARE”
WAVES
PARTS OF THE TRANSFORMER
CONSIST OF ONLY ONE DEVICE!
THE TRANSFORMER ITSELF!
IT CONSIST OF 2 COILS WHICH “STEP
DOWN” OR REDUCE THE VOLTAGE
DOWN TO 5 AND 12 VOLTS
PARTS OF THE VOLOTAGE
REGULATOR
RECTIFIER-MAKE AC BACK INTO DC
CAPACITORS-SMOOTH OUT AC
RIPPLES LEFT INTO SMOOTH DC
COILS- FILTERS OUT AC
ESD- ELECTORSTATIC
DISCHARGE
AS LITTLE AS 10 TO 30 VOLTS CAN
DESTROY COMPONENTS ON A
MOTHERBOARD!
YOU CAN ONLY FEEL VOLTAGE OF
2000 VOLTS OR GREATER!
CMOS CHIP MOST SUCCEPTIBLE TO
ESD
PREVENTING ESD
USE ANTI STATIC BAGS FOR
COMPUTER COMPONENTS
USE ANTI STATIC WRIST BAND WHEN
WORKING ON PC’S AND GROUND
YOURSELF OF MAT OR PC FRAME
STAY AWAY FROM MONITORS WHEN
WEARING THIS, THEY HAVE 20,000
VOLTS WHICH COULD KILL YOU!
POWER SUPPLY USE MOLEX
CONNECTORS
P8 AND P9’S- USED ON AT
MOTHERBOARDS. BLACK WIRE FROM
P8 HAS TO LINE UP BESIDE BLACK
WIRE FROM P9
THE MOLEX ON THE ATX IS NOT A P8
OR P9 AND HAS BLACK WIRES
ALREADY AUTOMATICLY LINED UP
MOLEX CONNECTORS WIRE
COLORS
5 DC
GROUND
GROUND
12 DC
POWER SUPPLY FACTS
USE 200-230 WATTS
BREAK DOWN MORE THAN ANY
OTHER PART BESIDES FLOPPY DRIVES
WHEN HAVING PROBLEMS CHECK:
ALL CONECTIONS
FAN
FUSE
CLUES IT’S A POWER SUPPLY
PROBLEM
FREQUENT LOCKING UP WHEN
POWERING ON COMPUTER
OCASIONAL AND DIFFERENT ERROR
CODES WHEN BOOTING UP
FREQUENT LOCKING UP