Oki OKIPAGE 12i Series, Service Handbook

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2.2 Power Supply/Sensor Board
The power supply/sensor board consists of an AC filter circuit, a low voltage power supply circuit,
a high voltage power supply circuit, heater drive circuit, and photosensors.
(1) Low Voltage Power Supply Circuit
This circuit generates the following voltages.
(2) High Voltage Power Supply Circuit
This circuit generates the following voltages required for electrophotographic process from
+5 V, according to the control sequence from the main control board. When cover open state
is detected, +5 V supply is interrupted automatically to stop the supply of all high-voltage
outputs.
Output voltage Use
+5 V
+30 V
+8 V
–8 V
+3.3V
Logic circuit supply voltage
Motor and fan drive voltage and source voltage for high-voltage supply
RS-232C line voltage
RS-232C line voltage and PS board supply voltage
LED head supply voltage
(3) Photosensor
The photosensor mounted on this power supply/sensor board monitors the status of paper
being fed through the printer during printing.
Output Voltage Use Remarks
CH
DB
SB
TR
CB
Voltage applied to charging roller
Voltage applied to developing roller
Voltage applied to toner supply roller
Voltage applied to transfer roller
Voltage applied to clearing roller
Variable
-1.3 KV
-265 V/+300 V
-500 V/ 0 V
+500 V to +3.5 KV/-1100 V
+400 V/-1350 V