Oki 10i, Service Manual

Page: 24 / 248

Page: 13
Service Manual - OKIPAGE10i
Chapter 2 Operation Description
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.
Output voltage Use
+5 V Logic circuit supply voltage
+ 30 V Motor and fan drive voltage and source voltage for high-voltage supply
+8 V RS-232C line voltage
-8 V RS-232C line voltage and PS board supply voltage
_3.3V LED head supply voltage
(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 Remarks
CH -1.3 KV Voltage applied to charging roller
DB -265 V/+300 V Voltage applied to developing roller
SB -500 V/ 0 V Voltage applied to toner supply roller
TR +500 V to +3.5
KV/-1100 V Voltage applied to transfer roller Variable
CB +400 V/-1350 V Voltage applied to clearing roller
(3) Photosensor
The photosensor mounted on this power supply/sensor board monitors the status of paper being fed
through the printer during printing.
The sensor layout diagram is shown in Figure 2-2.