Controlling The Separation Charging Current; Operation - Canon CLC 1120 Service Manual

D. Controlling the Separation Charging Current

1. Operation

The separation charging control mechanism has the following items of control:
1. Controlling the separation charging DC component to a constant current.
2. Controlling the separation charging AC component to a constant voltage.
3. Controlling the current and the voltage to suit the type of copy paper and the reading from
the environment sensor.
The CPU PCB controls the current and the voltage to suit the type of transfer medium
(regular paper, thick paper, transparency) and the reading from the environment sensor.
Each of the signals is used for the following:
[1] SPDCC (separation charging DC component ON/OFF control signal)
When '1', the charging DC component output is ready.
[2] SPDCI (separation charging DC component current level control signal)
Controlled to +3 to +11 V; at +3 V or more, the high voltage output is generated.
[3] SPACC (separation charging AC component ON/OFF control signal)
When '1', the charging AC component output is ready.
[4] SPACI (separation charging AC component voltage level control signal
Controlled to +3 to +11 V; at 11 V or less, the high-voltage output is generated.
[5] ACSBY (AC component drive control signal)
Then '1', the HVT-AC PCB is ready for operation.
[6] AC-ERR (HVT-AC PCB error signal
When '0', an error is detected in the HVT-AC circuit.
DC driver PCB
J1012
-B11
-B10
-B9
-B8
-B12
-B4
COPYRIGHT © 1999 CANON INC.
[1]
SPDCC
[2]
SPDCI
[3]
SPACC
[6]
SPACI
[5]
ACSBY
[4]
AC-ERR*
Figure 6-304
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 6 IMAGE FORMATION SYSTEM
HVT-AC PCB
J421
-3
-4
J104
-5
-6
-2
-10
Separation
charging
6-21