Jon Gerow · 06-26-2006 · Category: Defining the connectors of an
ATX power supply As stated earlier, there are several connectors
on an ATX power supply. Several connectors with several
different wires providing several different voltages. In this
section, we'll take a look at each of the connectors on a
typical ATX power supply. connector is a 20-pin ATX power supply
connector. As you can see from the color-code to the left of the
photo, it supplies many different voltages (+3.3V, +5V, +12V,
-12V, -5V) as well as a number of ground wires and a couple
signal wires ("Pwr On" which is how the motherboard tells the
power supply to turn on and "Pwr Good" which reports back that
the voltage of 3.3V and 5V are within spec) There's also a +5V
stand by (+5VSB) that constantly supplies power to the board
even when the PC is off. This voltage is used for several
different CMOS functions like Wake On LAN, Wake On Ring, etc.
The connector above is still an ATX main power connector, but is
of the 24-pin variety. One each