Specifications

COPYRIGHT © 2001 CANON INC. 2000 2000 2000 2000 CANON DADF-J1 REV.0 MAR.2001
CHAPTER 2 OPERATIONS AND TIMING
2-34
2.4.6 Controlling the Separation Motor (M4)
The following is a control diagram of the separation motor (M4), which is a DC motor.
The circuit is used for the following:
• Turning on/off the motor.
• Controlling the rotation speed of the motor.
• Controlling the overcurrent protective mechanism for the motor.
F02-204-12
When the CPU generates the motor speed rotation signal (SPPWM), the separation motor
(M4) starts to rotate in a specific direction. The separation motor clock sensor (PI2) sends
the rotation speed signal (SPCLK) of the separation motor to the speed control circuit,
which in response compares it against the speed reference signal (SEPCLKREF), and sends
the result (speed control signal; SPMFV) to the CPU.
In turn, the CPU varies the rotation speed signal to suit the speed control signal. LED3
remains on as long as the rotation speed of the motor is within a specific range, and goes off
when the speed falls out of the range.
The current detection circuit monitors the current flowing to the separation motor at all
times; if the current exceeds a specific level, it generates the separation motor stop signal
(SPLIM) to stop the motor. If the separation motor stop signal is generated continuously, the
CPU will assume a fault in the separation motor, and causes the copier to indicate an error
code (E405) on its display.
E405
Indicates a fault in the separation motor (M4).
Indicates a fault in the separation motor clock sensor (PI2).
Indicates a fault in the ADF controller PCB.
M4
SPLIM
SPPWM
SPCLK
SEPCLKREF
SPMFV
+24R
+5V
J12
J8
PI 2
Speed
control
circuit
Current
detection
circuit
Q1
CPU
Q48
Q50
LED3
Q7 Q17
1
2
5