HP 8110A Service Manual page 215

HP 811OA Se
r
vice Guide
Fun
ctional
U
nits on t
h
e
P
C
B
oa
rd
The P ower Supply functional units, and what they do, are as
f
ollows :
Unit
Function
Primary Section :
7- 6
F
unctio
n
al Desc
r
i
p
tio
n
1-Filtering and Overvoltage
P
rotection
Ensures that transient and overvoltage damage
is
p
revented
2-Fuse and Switch
Provides Surge current
p
rotection
a
nd
connection to AC
p ower.
3-Bridge
R ectifier and Blocking Capacitor
R ectifies and smooths AC input
4-PWM Control Unit, Switching
T
ransistor and
T
ransformer
The Pulse-Width Modulation Control Unit
controls the Switching
T ransistor, which
transfers p ower into the
T
ransformer
5-Overload P rotection
Monitors and controls overload conditions
6-'Soft-start' at Power-up
Ensures that voltages are gradually increased
for
p rotection
o
f the
p ower supply
a
nd the
instrument
7-Temperature Control
S
huts down the
p ower supply if the
f ans cannot
m
aintain α safe operating temperature
Secondary Section :
8-Rectifier & Filter
f or D C Supplies
R ectifies A C
p ower and filters switching
n
oise
9- -5 .2V
S
upply Direct
p ower controlled supply
10- f32V,
f
12V, +5 .1
V
S
upplies
Linear
p ower controlled supply
11- +32V Regulator Gate Supply
O perates +32V regulator
12-Overvoltage P rotection
Transzorb diode
p
rotection for overvoltages
13-Short-circuit Current
D
etection
Controls excessive current dissipation
14-Fan Control & Short Circuit Monitoring
Ensures that the
f ans are operating correctly