AL-1456 (serv.man14). Electrical section - Sharp Copying Equipment Service Manual (repair manual). Page 13

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AL-1555 ELECTRICAL SECTION 12 - 13
The control circuit is subject to negative feedback from the secondary
side as shown in fig (4). A photo coupler (PC002) is employed to insu-
late between the primary side and the secondary side to feed back the
control signal to the primary side. 
(4) Overcurrent protection circuit (Primary side)
The inverter circuit of the primary side is connected with the current
detection resistor R102. When an overcurrent occurs in the secondary
side, the current flowing through the primary side inverter Q001 is
increased. The current is detected by R012, and passed through R013
to IC701 overcurrent restricting pin (3 pin) to turn OFF Q002, shutting
off all power. To resupply the power, turn off and on the power. Refer
to fig (4).
(5) Rectifying/smoothing circuit (+5V)
fig (6) Rectifying/smoothing circuit
The high frequency pulse generated by the inverter circuit is
decreased by the converter transformer, rectified by the high frequency
diode D103, and smoothed by C103 and C104. 
fig (7) +5V rectifying/smoothing circuit voltage waveform
Voltage waveform
Voltage waveform
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