Oki OKIOFFICE84 Maintenance Manual page 288

R51
3)
R51
IOGA4
DBON1
DBON2
DBPWM
TR1PWM
CHPWM
TR2PWM
40672201TH Rev. 4
High-voltage and medium-voltage control
High voltages are activated by IOGA4 and generated by the high-voltage circuit
inside the power supply unit. The CH (charge) voltage of about -1.30kV is used for
the charge roller. The TR1/TR2 (transfer) voltage of about +3.9kV/-0.75kV is used
for the transfer roller.
Medium voltages are activated by IOGA4 and generated by the medium-voltage
circuit inside the power supply unit. The SB1/SB2 (toner supply) voltage of about
+0V/-450V is used for the toner supply roller. The DB1/DB2 (developing) voltage
of about +265V/-265V is used for the developing roller. The CB (cleaning) voltage
of about +400V/-1.35kV is used for the cleaning roller.
Figure A3.1.15 shows high/medium voltages control.
* Signals used to control the high/medium-voltages are listed below.
Signal Name
CHON "1": CH is output.
DBON1 "1": + ive polarity voltage of DB/SB is output. (+265V)
DBON2 "1": - ive polarity voltage of DB/SB is output. (-265V)
TRON1 "1": + ive polarity voltage of TR is output.
TRON2 "1": - ive polarity voltage of TR is output.
CB1ON "1": + ive polarity voltage of CB is output.
CB2ON "1": - ive polarity voltage of CB is output.
P2H
High-voltage
TR1/TR2
generation
circuit
Medium-
voltage
generation
circuit
DB1/DB2
SB1/SB2
Figure A3.1.15 High/Medium Voltages Control
Description
Contact assy.
Charge roller
CH
Cleaning roller
CB
A3 - 18
(-1.30kV)
(+3.9kV)
(-0.75kV)
(+400V)
(-1.35kV)
Developing roller
EP drum
Toner supply roller
Transfer roller