Hitachi 46W500 Training page 19

DP-3X DEFLECTION PROTECT POWER SUPPLY SHUTDOWN DIAGRAM
RH32 allows ABL fluctuations to manipulate the Trigger
Point of Shut Down as screen brightness varies.
ABL is inverse proportionate to brightness.
This prevents false Shut Down triggering.
Active
Normal
PROTECT _DEF
See Power Supply Shut Down
Circuit Diagram for continuation.
Vertical Output Circuit
I601
10
R629
0.68 Ohm
C604
Q604
R630
C610
Excessive Vertical Current Det.
If the Vertical Output IC has a problem, R629
will sense the current rise. The voltage drop will
be reflected at the base of Q604 turning it on
and producing a Shut Down high.
ABL
PPD4
6
28V
DK90 Monitors the -5V and +5V lines going to the DCU.
If the -5V line is loss, the +5V line provides the Shut Down Hi.
D608
R632
R631
Any fluctuations in High Voltage will also be
reflected by the 50P output P/P.
By monitoring the 50P (50 Pulse) rises in High Voltage
will be sensed. If High Voltage climbs too high, DH15
will fire and trigger a shut down event.
DH14 will fire and stop High Voltage Horz. Drive
Flyback
TH01
3
5OP
4
RH32
RH25
DH15
RH24
Hi Volt
H. Drive
Excessive Hi
IH01
Voltage Det.
1
H. Drive
DK90
CK90
High Voltage
Sensing Circuit
RH23
DH13
5
LH06
29.01V
CH17
Stops H. Drive
7
OVP
CH10
RK98
+5V
RK97
-5V
DH14
RH26
RH09
-5V Loss Det.
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