TM 5-3610-285-14
Developer and Fixer Recirculation Pumps Circuit
Developer and Fixer Replenishment Pump Unit Circuit
Timer Bell Circuit
Gage Illumination Circuit
Water Control Circuit
Standby Control Circuit
a.
Transport drive circuit.
(1)
Controls on/off operation and speed of transport drive motor. A switch controls on/off operation of the
motor while a variable-speed knob controls its speed.
A speed indicator dial indicates speed of transport mechanism in
centimeters per minute.
(2)
Actuating MAIN DRIVE switch (S5). When the top cover is in place (S7 actuated), S5 provides an ac
voltage to the motor speed controller (Al). The motor speed controller provides dc drive for the main motor. The voltage
provided to the motor is established by adjusting TRANSPORT SPEED control (R2). The motor speed controller
maintains the proper voltage to the motor and the proper drive speed. Interrupting the signal from R2 to the motor speed
controller (Al), pin P1 will stop the drive motor. The optical-coupler (U4) on circuit board 500 is turned on when the
processor is not in standby. When the processor enters standby, U4 is turned off. This interrupts the signal between R2
and P1 of the motor speed controller and shuts off the main drive motor. Actuating MAIN DRIVE switch (S5) also
provides power to the 5 volt regulator (U2) on circuit board 600. This powers the speed readout meter by way of wires 53
and 54. The speed readout meter is also provided a filtered signal from the tach generator by way of CR1, C1, R1 and
R3 on. circuit board 900. The speed readout meter displays the filtered signal from circuit board 900 as the drive speed
in centimeters per minute. Potentiometer R3 on circuit board 900 allows calibration for the speed readout meter.
b.
Developer heater circuit.
(1)
Consists of a developer thermostat which controls operation of developer heater and maintains a preset
temperature. Developer heater circuit is activated when pump switch is on.
(2)
Circuit description.
(a)
Circuit board 600. Actuating MAIN DRIVE switch (S5) applies an ac voltage to transformer T1. This
voltage is stepped down to 16 V ac and rectified to dc by circuit CR1. The rectified dc voltage is filtered by capacitors C1
and C3, and regulated to 12 V dc by voltage regulator U1. When dryer fan switch (S3) is actuated, the regulated 12 V dc
energizes developer temperature control circuit board 700.
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