Controlling The Belt Motor; Outline - Canon DADF-G1 Service Manual

2.8 Controlling the Belt Motor

2.8.1 Outline

The following figure shows an outline of the circuit used to control the belt motor:
The belt motor is a DC motor.
The microprocessor (Q1) on the DADF controller PCB sends to the drive circuit the belt
motor drive signal (BMON), belt motor rotation direction signal (BDIR), and belt motor ro-
tation speed control signal (BMPWM).
When the belt motor (M3) rotates, the belt motor clock sensor (S10) sends the belt motor
clock signal (BCLK1) to the microprocessor (Q1). In response, the microprocessor (Q1)
compares the belt motor clock signal (BCLK1) against the rotation speed stored in advance,
and varies the belt motor rotation speed control signal (PMPWM) so that the speed will
match the setting, ensuring that the belt motor (M3) will always rotate at a specific speed.
Q1
CPU
COPYRIGHT© 2000 CANON INC.
DADF controller PCB
BMON
BDIR
Drive
circuit
BMPWM
BCLK1
F02-208-01
CANON DADF-G1 REV.0 OCT. 2000
CHAPTER 2 OPERATIONS AND TIMING
J7-1
J7-2
Belt motor
clock sensor
J9-B4
Belt motor
M3
S10
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