OKIDATA OKIPAGE 20, Руководство по обслуживанию

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Service Manual - OKIPAGE20
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 Reset circuit, RS232C Line voltage
-8 V RS232C Line voltage
+3.8V LED head supply voltage
(2) High Voltage Power Supply Circuit
This circuit generates the following voltages necessary for electrophotographic process from +30 V,
according to the control sequence from the main control board. When cover open state is detected, +30 V
supply is automatically interrupted to stop the supply of all high-voltage outputs.
Output Voltage Use Remarks
Sub-CH -15 Microline Voltage applied to Sub charging roller
CH -1.3 KV Voltage applied to charging roller
DB -220V/+300V Voltage applied to developing roller
SB -450 V Voltage applied to toner supply roller
TR +4 KV/-1.3 kV Voltage applied to transfer roller Va only
CB +450 V/-1350V Voltage applied to cleaning 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.