Controlling The Developing Bias; Outline - Canon iR2200 Service Manual

7.2 Controlling the Developing Bias

7.2.1 Outline

Both DC bias and AC bias are applied to the developing cylinder. The output is controlled
by the composite power supply PCB based on the control signal from the DC controller
PCB.
The following relate to the developing bias control system:
[1] Controlling the DC developing bias to a specific voltage level
[2] Controlling the AC developing bias to a specific voltage level
24 VDC input from
main power supply
J135
DC bias
J301 J136
ON signal
-B1 -B12
AC pulse
ON signal
-B4
Serial
communication
DC bias level signal
J301 J136
-A3 -A10
-A1 -A12
AC bias
J301 J136
ON signal
-B2 -B11
The AC pulse ON signal is used as the primary charging output enable sig-
nal when controlling primary charging.
Memo
COPYRIGHT © 2001 CANON INC.
Composite power supply PCB
+24V
Transformer
drive signal
-B9
DC bias control signal
Transformer
drive signal
2000 2000 2000 2000
CHAPTER 4 IMAGE FORMATION SYSTEM
High-voltage
main
transformer
(for DC)
Output
control
Voltage level
Developing
AC bias
high-voltage
transformer
(for AC)
F04-702-01
CANON iR2200/iR2800/iR3300 REV.0 MAR. 2001
Photosensitive
drum
Voltage
J130-1
detection
Developing
cylinder
4-19 P