Ricoh Robin Service Manual page 62

24 June 1994
7.3 TRANSFER/SEPARATION CORONA CIRCUIT
VA [24]
SC [ 24]
TC [ 24]
GND [0]
Main Board
(PCB1)
To apply the negative charge for the transfer corona, the main board outputs
a LOW signal (CN117-13) shortly after the Start key is pressed.
To apply an ac charge for the separation corona, the main board also outputs
a LOW signal (CN117-14) at about the same time.
The TC/SC power pack has a dc to dc converter and a dc to ac inverter. The
dc to dc converter changes +24 volts to –5.0 kilovolts for the transfer corona.
The inverter changes +24 volts to the 3.8 kilovolts ac (500 Hz) for the
separation corona.
The separation corona circuit in the TC/SC power pack has a current leak
detection circuit for safety. When this circuit detects that more than 3.0
milli-amperes is being supplied to the separation corona, the separation
corona turns off immediately. When the main switch is turned off and on, or
the front cover or the exit cover is opened and closed, this condition is
cleared.
IMAGE TRANSFER AND PAPER SEPARATION
CN1-1
CN117-15
CN117-14 CN1-2
CN117-13
CN1-3
CN117-12
CN1-4
2-43
Power Pack
- TC/SC
Transfer
(P2)
Control
Separation
Corona