What is the output voltage of the no-load? What is the load output voltage?
Power supply test
As a source of personal computer power, but also with the progress of personal computers and change. From the previous 100W AT power supply to today's 450W or even higher ATX power supply, not only the power in continuous climb, the output current is also increasing, +5 V output current has more than 30 amps.
Since the announcement of the ATX2.01 power supply standard in January 1998, after the production of power are compatible with this standard, but the output voltage of each voltage is increasing. We use the ATX switching power supply, the output voltage of + 12V, -12V, +5 V, -5V, +3.3 V and several different voltage. Under normal circumstances, the above-mentioned several kinds of voltage output range allows the error is generally within 5%, as shown in the table below, can not have too much range of fluctuations, or prone to crash data loss situation.
Standard voltage value Wire color Minimum voltage Maximum voltage value
+ 5V red 4.75 5.25
-5V white -4.75 -5.25
+ 12V Yellow 11.4 12.6
-12V blue -11.4 -12.6
+ 3.3V Orange 3.135 3.465
Power plug on the motherboard ATX power output connector
ATX power supply 20-pin output voltage and function definition table
Pin Name Color Description
1 3.3V orange +3.3 VDC
2 3.3V orange +3.3 VDC
3 COM black Ground
4 5V red +5 VDC
5 COM black Ground
6 5V red +5 VDC
7 COM black Ground
8 PWR_OK Gray Power Ok (+ 5V & + 3.3V is ok)
9 5VSB Purple +5 VDC Standby Voltage (max 10mA)
10 12V Yellow +12 VDC
11 3.3V Orange +3.3 VDC
12 -12V blue -12 VDC
13 COM Blue Ground
14 / PS_ON green Power Supply On (active low)
15 COM black Ground
16 COM black Ground
17 COM black Ground
18 -5V white -5 VDC
19 5V red +5 VDC
20 5V red +5 VDC
