CHAPTER 4 POWER
MOTHERBOARDS
Form Factor – This designates a particular type of motherboard in re guard to
 Size
 Shape
 Major features
FORM FACTORS
 AT – outdated
 ATX – most popular
 MICRO ATX
 NLX
 BTX – newest
AT form factor is outdated and rarely seen today, but dominated the industry for more than 10 years
Had a smaller version called the baby AT
Used two power connectors P8 & P9
ATX – most popular form factor today
 Uses 1 power connector: P1
 Has a number of variations
Mini – ATX
Flex ATX
Micro ATX – major differences
But BTX may beat it
BTX (balanced technology extended)
 Newest form factor
 Supports newest standards (usb 2.0 sata)
 1 P1 power connector but can support auxiliary power connectors as well.
 Specifically designed to improve air folw
LPX mini LPX
 Becoming outdated
 Low profile computers only
 1 expansion slot uses a riser card into which expansion slots are plugged
 Heat is a problem
 Difficult to upgrade
NLX
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Improved version of lpx
Also uses a riser card, sometimes called a daughter board
Fixed some of the problems of the LPX
Supports AGP
Can have larger dims
Uses ATX power supply
BACK PLANE SYSTEMS
 No true motherboard
 The back plane is a board that may contain basic bus and power circuitry to support the circuit
boards that plug into its connects
Back plane computers=dedicated servers:multiple processor board
TYPES OF CASES
TOWER – offers most flexibility for expansion
 Offers most flesibility for expansion
 Large footprint
 Has 2 smaller sizes – midsized tower – mini tower
DESKTOP – becoming less popular
 Smaller size is called a slimline.
 Use lpx, mini lpx, nlx boards
NOTE BOOK CASES
 Very proprietary
 Emphasize less power, heat, space & more portable
PROPERTIES OF ELECTRICITY
 VOLTS – (V) a measure of electrical pressure differential
 AMPERE or AMP (A) a measure of electrical current
 OHMS – a measure of the resistance to the flow of electricity
 Watts – (W) a measure of electrical power
# volts X # of amps = # of watts
10V X 50A = 500W
Watts are used to measure the total amount of electrical power needed to operate a device
SIGNAL DISTORTION
Damage to a signal caused by interference, either EMI or RFI
ATTENUATION
The decrease in strength of a signal over a distance. More resistance means more attenuation
AC – alternating current
 A cheap way of moving electricity great distances
DC – direct current
 Electricity that only flows in one direction
 DC is what electronic equipment uses
HOT – electricity coming in
NEUTRAL – electricity going out
GROUND – an escape route for out of control electricity
American AC power – 110 volts
Europe AC power – 220 volts
ELECTRONIC DEVICES
 Transistor – a gate or switch that can serve to amplify the flow of electricity
 Capacitor – a device that can hold a charge. Used to smooth or even out the folw of electricity
 Diode – a semiconductor that allows electricity to flow in only 1 direction
 Resistor – a device that can limit the amount of electricity that can flow through it
ELECTRICAL THREATS
 ESD
 EMI
The flow of electricity through metal generates a magnetic field
SPIKES & SURGES in electrical current
Devices that can protect against threats
 Surge protectors
 Dataline protectors
 Line conditioners – protect against spikes & sags but not blackouts
 Ups – uninterruptible power supply
Ups protect against almost all spikes & surges, provide power conditioning and will provide power for a
short time in case of a blackout.
2 types
 Standard
 Intelligent – comes with it’s own software. Can perform monitoring, diagnostics and will shut
down the computer in case of a black out.