Chapter 4. Power supply

A145-watt power supply drives your computer. The power supply provides 3.3-volt power for the Pentium III microprocessor, core chip set, and 5-volt power for PCI adapters. Also included is an auxiliary 5-volt (AUX 5) power supply to provide power to power-management circuitry and a Wake on LAN adapter. The power supply converts the ac input voltage into four dc output voltages and provides power for the following:

System board

Adapters

Internal drives

Keyboard and auxiliary devices

USB devices

A logic signal on the power connector controls the power supply; the front panel switch is not directly connected to the power supply.

The power supply connects to the system board with a 2 x 10 pin connector.

Power input

The following table shows the power input specifications. The power supply has a manual switch to select the correct input voltage.

Table 8. Power input requirements

Specification

Measurements

 

 

Input voltage, low range

100 (min) to 127 (max) V ac

 

 

Input voltage, high range

200 (min) to 240 (max) V ac

 

 

Input frequency

50 Hz ± 3 Hz or 60 Hz ± 3 Hz

 

 

Power output

The following figures show the power supply output of all the connectors, including the system board, DASD, PCI, and auxiliary outputs.

Table 9. Power output (145 watts)

Output voltage

Tolerance

Minimum current

Maximum current

 

 

 

 

+5 V dc

+5% to -5%

1.5 A

18.0 A

 

 

 

 

+12 V dc

+5% to -5%

0.02 A

4.2 A

 

 

 

 

-12 V dc

+10% to -10%

0.0 A

0.4 A

 

 

 

 

+3.3 V dc

+5% to -5%

0.0 A

10.0 A

 

 

 

 

+5 V ac (auxiliary)

+5% to -5%

0.0 A

0.720 A

 

 

 

 

The total combined 3.3 V and 5 V power must not exceed 100 watts.

© Copyright IBM Corp. 2000

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IBM PC 300GL manual Power supply, Power output, Power input requirements Specification Measurements