Pedestal Motor Control Circuit; Outline; Mechanism - Canon NP6330 Service Manual

III. PEDESTAL MOTOR CONTROL CIRCUIT
A. Outline
Figure 8-301 shows the circuit that controls the pedestal motor (M1), and the circuit
has the following functions:
Turns on and off the pedestal motor
Rotates the pedestal motor at a specific speed
The pedestal motor (M1) is a DC motor equipped with a clock pulse generator. When
the motor rotates, clock pulses (MMCLK) corresponding to the revolution of the motor
are generated. The speed control circuit maintains the revolution of the motor by
matching the phase of the frequency of these pulses and that of the frequency of the
reference signal.
Pedestal
controller
PCB
B. Mechanism
When the pedestal motor drive signal (PEDMD) from the pedestal controller circuit
goes '1', the drive circuit of the motor driver turns on, thereby rotating the pedestal motor
at a specific speed.
While the pedestal motor is rotating at a specific speed, the motor driver PCB sends
the constant speed state signal (LOCK*=1) to the pedestal controller PCB. The signal
goes '0' if the revolution of the motor fluctuates for some reason.
If LOCK*=0, the operation of the machine is stopped, and 'E901' is indicated on the
copier's display.
COPYRIGHT © 1997 CANON INC.
J108
-1 24VB
J109
-1 PEDMD
Speed
-2 LOCK*
control
-3
circuit
Reference signal
Figure 8-301
CANON NP6330 REV.0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 8 PAPER DECK PEDESTAL
Clock pulse
generator
Drive
Drive
circuit
current
M1
Pedestal
motor
Hall IC output
MMCLK
Motor driver PCB
8-5