M14 (Charger Cleaning) Control - Minolta Di551 Service Manual

CORONA UNIT SECTION

[5] M14 (Charger Cleaning) Control

CHGM A
CHGM B
PRCB
24V/1
5V/2
S.GND
P.GND
DCPS
M14 (charger cleaning) is a DC motor powered
by 24 VDC and is controlled by PRCB (printer
control board).
1. Operation
a. Purpose of driving
M14 (charger cleaning) is used to drive the
charging wire cleaning unit.
b. Operation timing
The charging wires are cleaned when SW2 (sub
power) is turned ON and when the fixing temper-
ature is lower than 50°C. They are also cleaned
after the specified copy count is reached.
* Changeable with the 25-mode DIP SW
c. Cleaning operation
Normally, the charging wire cleaning unit is on
the front side of the machine. It moves back and
forth to clean the charging wires. The movement
direction is changed by changing the rotational
direction of M14 (charge cleaning).
The rotational direction of M14 and the position
of the cleaner are detected by monitoring the cur-
rent value of M14 with PRCB (printer control
board).
2. Signals
a. Output signal
(1) CHGM_A, B (PRCB to M14)
M14 M14 (charger cleaning) drive control signal.
The drive direction of M14 is controlled by switch-
ing between the drive current directions of two
signals.
Status
Forward stroke
of cleaning
Backward stroke
of cleaning
Stop
2-F-4
CHGM_A CHGM_B
H L
L H
L L