The computer case contains the framework to support the
internal components of a computer while providing an
enclosure for added protection
The power supply must provide enough power to the components that
are currently installed. the power supply converts Alternative Current
(AC) power into Direct Current (DC)
Ohm's law
Four basic units of electricity
Voltage (V)
Voltage is a measure of work required to move a
chart to one location to another. Voltage is measure in
Volts (v)
Current (I)
Current is a measure of the amount of electrons moving
through a circuit per second. Current is measure in Amperes
or Amps (A)
Power (P)
Power is a measure of the work required to move electrons through a
circuit (voltage), multiplied by the number of electrons going through
that circuit per second (current). Power is measure in Watts (W).
Resistance (R)
Resistance is the opposition to the flow of current in a
circuit. Resistance is measure in Ohms
A basic equation, known as the Ohm's law, expresses how three of
the terms relate to each other. It states that voltage is equal to the
current multiply by the resistance: V=CR
Internal PC Components
Motherboards
The Motherboard is the main printed circuit board and contains the buses, or electrical pathways,found in a
computer. The Motherboard accommodates the central processing unit (CPU), Random access memory (RAM),
Expansion Slots, Heat Sink, Fan Assembly and the Basic Input/Output System (BIOS) chip
CPUs
Cooling System
ROM
RAM
Memory Medules
External Ports and Cables
Video ports and cables
A video port connects a monitor to a computer using a cable. Video
ports and monitor cables transfer analog signals. digital signals, or both
Other ports and Cables
Input/Out (I/O) ports on a computer connects peripherals devices
such as Printers,Scanners and portable devices the following ports
and cables are commonly used: Serial, USB, FireWire, Parallel,
SCSI, Network, PS/2 and Audio
Input and output devices
Input devices
An input device enters data or instructions into a computer.
Here are some examples of Input devices: Mouse and
Keyboard, Joystick, Scanner
Output devices
An out put device presents information to the user from a computer. Here are
some examples of Output devices: Monitors and Projectors, Printers and Fax
Machines