1 0.2
Servicing the Power Supply
Theory of Operation
Introduction
Line Voltage Selector
and Transformer
Bridge Rectifiers and
:Regulators
The HP 8 1 12A power supply unit occupies part of the main
board Al and consists of the following four parts, as shown in
Figure 10.2-1:
•
Line voltage selector and transformer
•
Voltage rectifiers and regulators
•
Voltage and current sensing circuits
•
Power-down detection circuit
Lil\E
SELECT
-23V
Figµre 1 0.2-1 . Power Supply block diagram
Refer to Figure 10.2-2. The line-voltage selector-switches, S2 and
S3, connect the incoming line-voltage lines to an appropriate pair of
transformer inputs. The transformer provides six ac outputs and an
earth line to the bridge rectifiers.
There are three bridge rectifiers, all modular and therefore
replaceable:
Servicing the Power Supply 1 0.2-1
Summary of Contents for 8112A
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