31 August 1989
Down Operation
The bottom plate moves down either when the Down key is pressed or when paper runs out.
When either condition occurs, the flip-flop on the tray main board changes state (all outputs
change from LOW to HIGH or vice versa). Then, two things happen simultaneously: (1) The
timer circuit turns on, causing the LED in the Down key to blink; and (2) SSR100 turns on,
energizing the drive motor to move the tray down.
The tray down sensor is actuated when the bottom plate is fully lowered. This causes the
flip-flop to change back to its original state, which turns off SSR1 00 and resets the timer circuit.
The LED in the Down key stays on.
Up Operation
Up operation is started by opening and closing the cover while the bottom plate is in the down
position. The cover safety switch changes the state of the flip-flop to energize SSR101, which
turns on the drive motor to move the tray up. The drive motor stays on until the paper pushes
up the pick-up roller. The actuator on the pick-up roller bracket then moves out of the upper
limit sensor; this again changes the flip-flop?s state and the motor stops.
NOTE: If JP-118 on the tray main board is removed, the bottom plate moves up by opening
and closing the cover before the bottom plate actuates the tray down sensor.
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