Lecture on Computer Power Supplies and Electricity Basics

Introduction to Power Supplies

Power supplies convert electricity from AC (Alternating Current) to DC (Direct Current).
Computers use DC voltage.
Power supplies convert AC voltage from the power company to low voltage DC power for computer use.
Components of a power supply include:
- A fan for cooling
- Voltage information displayed on the unit
- Cables for connecting and powering components like the motherboard.

Direct Current (DC): Flows in one direction.
Alternating Current (AC): Changes direction constantly; supplied by power companies.
Voltage: The "pressure" of electricity (similar to water pressure in pipes).
- Incorrect voltage can damage devices (e.g., plugging a 120V appliance into a 220V outlet can fry the device).
Current (Amperage): Measured in amps; "pulls" electricity.
- Devices can draw more current if needed, but require proper voltage.

Using the wrong voltage can cause devices to not function correctly or be damaged.
Amperage affects charging speed (e.g., a 2.1 amp charger charges faster than a 1 amp charger).

Wattage is a combination of volts and amps required by a device.
Insufficient wattage leads to insufficient power for the computer.
It's important to have a power supply with enough wattage to meet the computer's demands.
Larger power supplies don't overpower computers—they only supply the required power.

Basic desktops generally need a 500W power supply.
More demanding tasks (gaming, video rendering) require more powerful power supplies.
A power supply that comes with the computer is usually sufficient for basic tasks like web browsing.

A faulty power supply can cause the computer not to turn on.
Power supply failures can result from burnouts, power surges, or lightning strikes.
IT support specialists should know how to diagnose and replace failed power supplies.