40930701TH DRAFT Vesion 20 /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 voltageOutput Voltage Use RemarksSub-CH -15 μA Voltage applied to Sub charging rollerCH -1.30 KV Voltage applied to charging rollerDB -220 V/+300 V Voltage applied to developing rollerSB -450 V Voltage applied to toner supply rollerTR +4 KV/-1.3 kV Voltage applied to transfer roller Variable + OnlyCB +450 V/-1350V Voltage applied to clearimng roller2.2 Power Supply UnitThe power supply unit consists of an AC filter circuit, a low voltage power supply circuit, a highvoltage power supply circuit, heater drive circuit, and photosensors.(1) Low voltage power supply circuitThis circuit generates the following voltages.(2) High voltage power supply circuitThis circuit generates the following voltages necessary for electro-photographic processingfrom +30 V according to the control sequence from the control board. When cover open stateis detected, +30 V supply is automatically interrupted to stop the supply of all the high-voltageoutputs.(3) PhotosensorThe photosensor mounted on this power supply unit supervises the paper running stateduring printing.
