Pre-Quenching Corona Circuit - Ricoh FT7770 Service Manual

30 April, '89

Pre-Quenching Corona Circuit

2.
begins with the application of +24 volts to CN850-1 (VP).
Circuit operation
This is the power source for the high voltage corona.
Additionally, +24
volts (VA) for the trigger photocoupler is applied at CN850-3.
When the Start key is pressed, the CPU energizes the cleaning bias power
pack by supplying a LOW output at CN202-B9. This action turns on the
LED, and the phototransistor energizes the pre-quenching corona (PQC).
The PQC stops at the same time as the main motor.
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