Epson Stylus C 60 Service Manual page 44

EPSON Stylus C60
+42Vline over voltage protection circuit :
The output voltage line is monitored by ZD52 and ZD87. If the output voltage
level of +42VDC line exceeds +48V, this circuit stops the operation of the
switching FET Q1 via PC1,Q82 and Q83, and prevents high voltage from being
applied to the secondary side.
+42VDC line drop limitation circuit :
PC1 drives with +36V and ZD90 is monitoring the voltage supplied to PC1. If the
supplied voltage level exceeds 37V, this circuit shuts down the +42V line
temporarily and prevents the over voltage from being applied to the PC1.
+42Vline over current protection circuit :
The output current level is monitored by the F51. When the abnormal current is
detected by F51, F51 blows and cuts off the +42V line output to the Main board.
+5V line constant voltage control circuit/+5V line over current protection circuit :
The output voltage level of the +5VDC line is monitored by the regulator IC51. If
abnormal voltage is detected, the information is fed back to the internal
comparator.
+5V line over voltage protection circuit :
The output voltage level of the +5VDC line is monitored by ZD53.
If the output voltage level of +5DC line exceeds +7V, this circuit stops the
operation of the switching FET Q1 via PC1,Q82 and Q83, and prevents high
voltage from being applied to the secondary side.
Operating Principles Electrical Circuit Operating Principles
Revision A
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