Canon iR6570 series, Service Manual

Page: 211 / 684

Chapter 7
7-13
F-7-16
The following signal is associated with the mechanism:
[1] dust-collecting roller bias remote signal; if '1', the dust-collecting roller bias turns on.
7.5.4 Pre-Transfer Charging Mechanism
7.5.4.1 Outline
0009-4079
The following items are associated with the pre-transfer charging control system:
1. controlling the constant current level of the DC bias
2. controlling the fixed voltage level of the AC bias
3. controlling the output to suit the environment (fuzzy control)
The following shows the construction of the system associated with the pre-transfer charging control mechanisms:
F-7-17
The following signals are associated with the mechanism:
[1] Pre-transfer/separation charging leakage detection signal; when the current is too high or too low, '0'.
[2] Pre-transfer charging control signal; controls the DC bias current and AC bias voltage generated by the high-voltage PCB.
[3] Pre-transfer/separation charging remote signal; turns on/off the pre-transfer/separation current output.
7.5.4.2 Controlling the Output to Suit the Environment (fuzzy control)
0009-4080
The pre-transfer charging current is optimized to suit the environment (i.e., reading of the environment sensor):
DC controller PCB
High-voltage PCB
DC -1000V
HVT_ROLLER_BIAS
[1]
Dust-collecting
roller
Scraper
J102A J4502
DC controller PCB
HVT_POST [3]
SEPARATE-LEAK-
DETECT [1]
High-voltage PCB
Pre-transfer charging wire
HVT_AC [2]
High-voltage AC transformer
AC+DC
J102A J4502
J4503