Canon DADF-B1 Service Manual page 29

CHAPTER 2 BASIC OPERATION
4. Controlling the Separation Motor (M1)
Figure 2-219 is a diagram of the control circuit used for the separtion motor (M1).
The separation motor is a DC motor, and the CPU (Q1) on the ADF controller PCB sends the
separation motor rotation speed control signal (SMPWM) and the separation motor rotation direction
signal (SMFWD, SMREV) to the drive circuit, which in response drives the separation motor.
The control circuit does no possess a circuit designed to communicate the state of the separation
motor back to the CPU (Q1). The rotation speed control signal (SMPWM) remains the same at all
times, and no correction is made even when changes occur in the rotation speed of the separation
motor because of external force.
Q1
CPU
The relationship between the separation motor rotation speed control signal (SMPWM), the
separation motor rotation direction signal (SMFWD, SMREV), and the separation motor is as shown
in Table 2-204.
Separation motor rotation
speed control signal
(SMPWM)
'0'
'1'
'1'
2-16
COPYRIGHT © 1999 CANON INC. CANON DADF-B1 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
ADF controller PCB
SMPWM
SMFWD
Drive
circuit
SMREV
Figure 2-219
Separation motor rotation
direction signal
(SMFWD)
'0'
'0'
'1'
Table 2-204
J5F-1
J5F-2
Separation motor rotation
direction signal
(SMREV)
'0'
'1'
'0'
Separation
motor
M1
Separation motor
operation
Stops
Rotates CW
Rotates CCW