Technical Reference Guide: HP Compaq 8100 Elite Series Business Desktop Computers

Technical Reference Guide www.hp.com 7-1
7
Power and Signal Distribution
7.1 Introduction
This chapter describes the power supplies and discusses the methods of general power and signal
distribution. Topics covered in this chapter include:
■ Power distribution (7.2)
■ Power Control (7.3)
■ Signal distribution (7.4)
7.2 Powe r Dis tr ib u tion
These systems use a common power source power supply unit contained within the system
chassis. Figure 7-1 shows the block diagram for power generation.
NOTES:
Connectors not shown to scale.
All + and
– values are VDC.
RTN = Return (signal ground)
Figure 7-1. Power Distribution and Cabling, Block Diagram
Conn Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6
P1 RTN RTN –12 V + 12 V m a i n +12 V m a i n + 12 V s b
P2 FANcmd Fan Speed PS On Pwr Good RTN RTN
P3 RTN RTN +12 Vcpu
+12 Vcpu
System Board
Power On
Power Control Logic, DC/DC Converter
Front Bezel
& Voltage Regulators
Fan
PS
+12 Vcpu
Power Button
Spd
+12 Vmain +12 Vsb
90 - 264 VAC
NOTE: Return (RTN or ground) not shown.
-12 V
P1
On
Pwr
Good
P2 P3
P3
1
2
3
4
1
2
3 4
P2
56
P1
6
1
3
4
Fan
Cmd
Power Supply Unit