CompTIA A+ Complete Study Guide

2.2. Identifying Purposes and Characteristics of Power Supplies

The computer's components would not be able to operate without power. The device in the computer that provides this power is the power supply (Figure 2.15). A power supply converts 110V or 220V AC current into the DC voltages that a computer needs to operate. These are +3.3VDC, +5VDC, −5VDC, +12VDC, and −12VDC. The jacket on the leads carrying each type of voltage has a different industry-standard color coding for faster recognition. Black ground leads offer the reference that gives the voltage leads their respective magnitudes. The +3.3VDC voltage was first offered on ATX motherboards.

Figure 2.15. A power supply

NOTE

The abbreviation VDC stands for volts DC. DC is short for ...