Ac Component Control - Ricoh FT5540 Service Manual

31 August 1989

15.3 AC COMPONENT CONTROL

The ac drive PCB controls the main motor, cooling fan, exposure lamp, and fusing lamp. The
SSR board controls the developer motor and the paper feed motor.
AC (hot) is supplied from RA1 and contacts through each ac component. AC neutral is applied
to both the ac drive PCB and the SSR board. In addition, 24 volts (Va) is supplied to each "+"
terminal of the SSRs, while the "-" terminal returns to the main board.
To energize a component, the main board supplies a LOW signal to the appropriate board,
which causes the SSR to turn on, completing the ac circuit to the component. To de-energize
the component, the main board removes the LOW signal from the board, turning it OFF.
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