Sharp AR-5132 Service Manual page 78

B. Lift motor drive circuit (E1MOT, E2MOT)
The lift up motor is rotated to lift the paper in the paper tray 3 to the transport level. The lift motor drive circuit drives the lift motor. There are two sets
of the lift up mechanism, each one is provided with the motors (E1MOT, E2MOT) and the drive circuit. These two are of the same composition. In
the following description, the E1MOT is described.
The lift motor is turned on/off by the CPU. When the level sensor 1 (LS1) described in the sensor section is turned off during paper transport, the
CPU turns on the lift motor (E1MOT) to turn on the sensor. The ON signal is outputted from the IC1-15 pin. The logical sum of this signal and the
limit sensor 1 (LMS1, HIGH when limited) is taken. Only when the limit sensor 1 is OFF (LOW), it is outputted from the IC6-3 pin. When the IC6-3
pin becomes LOW, a current is not supplied to the Q4 base, and Q4 is turned off. As a result, a current is supplied to the Q5 base from R79 to turn
on Q5 and to drive CN6.1 pin to about 0V. A voltage difference is generated between the both poles of the motor to supply a current to the motor.
When the level sensor detects the paper surface, the IC1-15 pin becomes HIGH to turn off Q5. At that moment, a voltage difference is generated
between the base and the emitter of Q11 to turn on Q11 and apply brake. D1 is the flywheel diode which operates at OFF.
+5V
R81
10K
15 2
P03
IC6-1
1
LHS1
C. Pickup clutch (P1CL, P2CL), separation clutch (BCL), resist clutch (RCL) drive circuit
The clutch transmits the paper transport motor (HMOT) drive power to the rollers, and it is of the same composition as the pickup clutches (P1CL,
P2CL), the separation clutch (BCL), and the resist clutch (RCL). In the following description, the pickup clutch 1 ((P1CL) is described.
Q13 (TD62003) is the Darlington driver with seven circuits, one of which is used to drive. When the IC1-19pin becomes HIGH, the transistor at the
output stage of Q13.4 is turned on to drive IC13-13 pin to about 0V, supplying the power to the clutch and transmitting the power.
DC2 4V
19 4 1 3
P07
Q13-4
+5V
R79
1.0K
Q5
Q4
3
GROUND
E1MOT drive circuit
2
DC24V CN1-2
6
P1CL CN1-6
Control PWB
P1CL drive circuit
DC 24 V
R19
4.7K
Q11
D1
D4
Control PWB
DC24V CN1-2 DC24V
P1CL CN1-6 P1CL
Interface PWB
11 – 6
2
DC24V CN6-2 CN6-2
1
E2MOT CN6-1 CN6-1
CN1-2 DC24V
CN1-6 P1CL
E1MOT
P1CL