Page: 12Service Guide OKIPAGE 10eChapter 2 Operation2.2 Power Supply/Sensor BoardThe power supply/sensor board consists of an AC filter circuit, a low voltage power supply circuit, a high voltage powersupply circuit, heater drive circuit, and photosensors.(1) Low Voltage Power Supply CircuitThis circuit generates the following voltages.Output voltage Application+5 V Logic circuit supply voltage.+38 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.(2) High Voltage Power Supply CircuitThis circuit generates the following voltages required for electrophotographic process from +5 V, according to the controlsequence from the main control board. When cover open state is detected, +5 V supply is interrupted automatically tostop the supply of all high-voltage outputs.Output Voltage ApplicationCH -1.3 KV Voltage to be applied to charge roller.DB -265 V/+300 V Voltage to be applied to a developing roller.SB -500 V/ 0 V Voltage to be applied to a sponge roller.CB +400 V/+3.5 KV Voltage to be applied to a cleaning roller.TR +500 V to +3.5 KV/-1100 V Voltage to be applied to a transfer roller. (Variable)(3) PhotosensorThe photosensor mounted on this power supply/sensor board monitors the status of paper being fed through the printerduring printing.The sensor layout diagram is shown in Figure 2-2 below.
