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

GROUND

HOTNEUTRAL

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 NETWORKTRANSFORMERVOLTAGE 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 DCREGULATES VOLTAGE TO CONSTANT

LEVELMONITORS 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