Computer Hardware Notes

Computer Components

Power Supply

  • Converts AC power from the wall into DC power for the computer.
  • Critical for providing the correct type of power to all components.

CPU Fan and Heat Sink

  • Sits directly on top of the CPU.
  • CPUs generate a lot of heat, and this system pulls heat away and dissipates it.
  • Without it, the CPU would overheat.

CPU

  • The "brain" of the computer, performing calculations and executing instructions.
  • Connects to the motherboard along with all other components.

Motherboard

  • The central component that connects all other parts of the computer.
  • Contains the wiring and circuitry necessary for components to communicate.

Memory Modules (RAM)

  • Inserted into memory slots on the motherboard.
  • Stores data that the CPU is currently working on.
  • Short-term storage; data is erased when the power is turned off.

Hard Disk Drive

  • Long-term data storage.
  • Connects to the motherboard using a SATA cable.

Optical Disk Drive (e.g., DVD ROM)

  • Another storage device; this example is a DVD ROM drive.
  • Larger than hard disk drives.
  • Typically uses an IDE cable (older) or SATA cable (newer) to connect to the motherboard.
  • Requires two cables: one for motherboard connection, one for power supply connection.

Expansion Card

  • Inserted into expansion slots on the motherboard.
  • Used to customize the computer and add functionality.
  • Examples:
    • High-end graphics card for gaming.
    • Audio expansion cards.
    • Networking expansion cards.

Power Supply Unit (PSU)

  • Delivers low voltage direct current (DC) power to PC components.
  • Contains:
    • Rectifier: Converts alternating current (AC) from the building to DC voltage.
    • Transformers: Step down to lower voltage.
    • Regulators: Ensure consistent output.
    • Filters and regulators.
    • Fan: Dissipates heat.
PSU Compatibility
  • Size and shape must be compatible with the system case and motherboard.
  • Consider screw and fan locations and power connectors.
  • Most desktop PC PSUs are based on the ATX form factor.
Voltage
  • Ensure the PSU is compatible with the outlet's voltage.
  • North American outlets typically provide 120 VAC (low line).
  • UK outlets provide 230 VAC (high line).
  • Data centers often use high line voltage for efficiency.
  • Most PSUs are dual voltage and auto-switching, but some have a manual switch or are fixed.
  • Operating voltages are marked on the PSU and its documentation.
  • AC voltage supply varies by country and distribution circuits.
  • PSUs have a wide tolerance range: 100−127100 - 127 VAC for low line, 220−240220 - 240 VAC for high line.