1.0 Hardware

1.3 Classify power supplies types and characteristics

A computer's power supply converts the AC (alternating current) provided by the main electrical supply of your home or office to DC (direct current) needed to operate the device. Power supplies may vary greatly in appearance and technical specifics (input and output) from one device to another.

A components form factor defines it's physical diminsions and characteristics. As a general rule, the form factor of a computer's components, the case, power supply, and motherboard, must all match.

  • AC adapter

    Primarily used for laptops, sometimes referred as a power brick. Accepts AC power input, provides DC power output. Model specific.

  • ATX proprietary

    Manufactured to fit specific models, does not always follow typical ATX power supply configurations.

  • Voltage, wattage and capacity

    Voltage is the measure of electrical potential difference between two points. Voltage can be measured between two points with a voltmeter. Computer power supplies traditionally accept alternating current (AC) as input and produce direct current (DC) as output.

    Wattage measures the rate of energy conversion and is figured by multiplying volts times amps (volts x amps = watts).

    Ampherage is the rate of the electron flow. The more electrons that flow past a given point at a given time, the higher the ampherage.

  • Voltage selector switch

    Switches power input between 115v and 230v AC

  • Pins (20, 24)

    Originally, the ATX motherboard was powered by one 20-pin connector. An ATX power supply provides a number of peripheral power connectors, and (in modern systems) two connectors for the motherboard: a 4-pin auxiliary connector providing additional power to the CPU, and a main 24-pin power supply connector, an extension of the original 20-pin version.