Quenching Lamp Circuit - Ricoh FT7770 Service Manual

30
April, '89

Quenching Lamp Circuit

3.
To turn on the quenching lamp, the CPU sends a +3-volt signal to the dc
drive board from CN208-A4. The dc drive board then provides a LOW out-
put at CN301-A19. This energizes a relay in the power supply unit. When
the relay closes, 485 volts ac is applied to the quenching lamp. The 485
volts ac is generated by a step-up transformer which has an input of 100
volts ac.
The quenching lamp turns on and off at the same time as the main motor.
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