Controlling The Charging Mechanisms; Controlling The Primary Charging Mechanism; Outline - Canon GP605 Service Manual

CHAPTER 6 IMAGE FORMATION SYSTEM
III . CONTROLLING THE CHARGING MECHANISMS
A.

Controlling the Primary Charging Mechanism

1.

Outline

Volume 2>Chapter 6>I.C. "Controlling the Primary Charging Current"
The primary charging mechanism is controlled for the following:
[1] Primary charging bias constant current
[2] Grid bias constant voltage
Figure 6-301 shows the construction of the primary charging control system.
When an overcurrent or an
undercurrent is detected, '0'.
When '1', high-voltage
output is ready.
J510A
1
HVDC-EN
2
PR-CNT
3
4
5
6
7
8
9
10
11
12
13
14
15
16
A voltage input between 0 and 12 V,
used to control the current level of the
primary bias.
Figure 6-301 Construction of the Control System
6-16
COPYRIGHT © 1999 CANON INC.
Relay PCB
1 2 3 4
J723
0 V
16
15
14
PR-ERR
13
GRD-CNT
12
11
10
9
8
7
6
5
4
3
2
1
A voltage input between 0 and 12 V, used to
control the voltage level of the grid bias.
CANON GP605/605V REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
The primary charging bias varies as
follows according to PR-CNT
potential.
1600µA
800µA
Primary charging wire
T601
J731
The grid bias varies as follows
according to GRD-CNT potential.
900V
400V
11V 12V
3V
PR-CNT
Grid wire
3V
11V 12V
GRD-CNT