Developing Rotary Motor Control - Canon MF8100 Series Service Manual

The operations of the main motor are discussed next.
The CPU in the DCNT Board rotates the motor by setting the /MAIMACC signal "L" through the ASIC.
The CPU monitors the MAIN MOTOR SPEED DETECTION (MAIMFG) signal. The CPU out-puts the /MAIMACC signal when the motor does not reach spec-
ified revs, and outputs the/MAIMDEC signal when it exceeds a specified rev. Then, the CPU controls these signals to adjust the motor revs to a specified value.
The CPU determines a main motor failure, then stops the printer engine, and notifies the failure to the video controller, under the following conditions:
1) The period of the MAIMFG signal does not satisfy a specified period within 100 ms after the start of main motor drive.
2) The period of the MAIMFG signal goes out of a specified period continuously for more than 1 seconds after it once reaches the value.

2.6.2.5 Developing Rotary Motor Control

This control is utilized to drive the developing rotary motor (DCM703).
The DCM703, a three-phase, eight-pole DC motor with a built-in encoder, drives the developing rotary.
The DCNT Board drives the motor by controlling the DEVELOPING ROTARY MOTOR ON (ROTMON) signal and DEVELOPING ROTARY SPEED CON-
TROL (/ROTMPWM) signal.
The illustration below shows the control circuit of the motor.
1) When the CPU cannot detect ENCODER DETECTION signal within 5 seconds after the start of the developing rotary motor drive.
DCNT Board
CPU
(IC101)
ASIC
(IC102)
DCNT Board
+5V
ROTMON Developing
rotary motor
driver
/ROTMPWM
(IC103)
CPU
(IC101)
+24VB
J110-8 J701-1
+24VB
-5
/MAIMACC
/MAIMDEC
-6
+3.3V
MAIMFG
-7
-4 24VGND
F-2-53
+24VA
FU103
J105-5 to -8
DEVELOPING ROTARY
MOTOR DRIVE signal
J105-3
ENCSNS1
-2
ENCSNS2
Developing rotary
Home position flag
+3.3V
J126-1
+3.3V
-4
ROTHPS
F-2-54
Main motor
DCM701
-4
M
-3
-2
-5
Developing rotary motor
DCM703
M
Encoder
Bk
Y
C
M
Developing rotary
home position
sensor
(PS51)
Developing rotary/toner level
detection circuit
Chapter 2
0008-1729
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