Power Supplies
Direct Current (DC) - one direction Alternating Current (AC) - changes directions constantly
Power Supply - converts AC we get from the wall outlet into low voltage DC power that we can use and transmit through our computer
Amps pull electricity while Voltage pushes electricity
Wattage - amount of volts and amps that a device needs
- most desktops can be powered with a 500W power supply
North, Central, and parts of South America use the 110-127 VAC standard for common wall sockets. Computers and power supplies sold in these regions are designed to use this level of power.
Most countries use the 220-240 VAC standard for common wall sockets. Computers and power supplies sold in these areas are designed to use this higher voltage.
| If a computer needs | But the wall socket delivers | The result will be |
|---|---|---|
| 220-240VAC | 110-120VAC | not enough power for the computer to run properly |
| 110-120VAC | 220-240VAC | too much power, which will damage the computer’s internal parts |
| Voltage | Examples of components that use each voltage level |
|---|---|
| 3.3V | DIMMs, chipsets, and some PCI/AGP cards |
| 5V | SIMMS, disk drive logic, ISA, and some voltage regulators |
| 12V | Motors and voltage regulators with high outputs |
Key takeaways
When selecting a power supply for a computer, the following items should be taken into consideration:
- Wall socket input voltage standard for the country where the computer will be used;
- The number and power consumption needs of the computer’s internal components;
- The motherboard model and form factor engineering specifications and requirements.