87
Power Supply
The 300 Watt power supply has a manual switch for selecting either 115 VAC (90-132 VAC)
range or 230 VAC (180-264 VAC) range for domestic or international locations. The input
frequency is 47-63 Hz, single phase. Input current is 7 amps maximum for the 115 VAC range and
3.5 amps for the 230 VAC range. The power supply has a typical efficiency of 70 percent at
maximum output load. The power supply is enclosed in a case that includes a fan for additional
airflow.
The 300-Watt power supply has the following DC output specifications:
Outputs
→
1
2
3
4
5
6
1
Nominal Output Voltages (VDC)
+5.0
2
+3.3
2
+12.0
-12.0
-5.0
+5.0
Maximum Current Rating (ADC)
30
22
10
0.8
0.5
1
1.
S5.0 VDC output voltage is always on.
2.
M5.0 V and +3.3 V combined power is 180W.
The power supply has two power cables, P1 and P2, that connect to ATX power connectors on the
system board.
The power supply has six peripheral device power cables (P3 through P8) and one floppy disk
drive power cable (P9). Depending on your system configuration, these cables connect in daisy
chains to the power supply and to each other as follows:
Configuration 1
Configuration 2
Power Supply
→
P3
→
P4
Power supply
→
P3
→
P4
→
P5
Power Supply
→
P5
→
P6
Power supply
→
P6
→
P7
→
P8
→
P9
Power Supply
→
P7
→
P8
→
P9
See Chapter 10, “Servicing System Components,” for details on replacing the power supply.
P1 Connector Pinout
Pin
Signal
Pin
Signal
Pin
Signal
Pin
Signal
1
+3.3V
6
+5.0 V
11
+3.3 V *
16
Ground
2
+3.3V
7
Ground
12
-12.0 V
17
Ground
3
Ground
8
Power Good
13
Ground
18
-5.0 V
4
+5.0V
9
5.0 V Standby
14
Remote On
19
+5.0 V
5
Ground
10
+12.0 V
15
Ground
20
+5.0 V
* + Sense
