WorkCentre 3210/3220 Multifunction Printer Service Manual 2-23Theory of OperationTransfer High Voltage (THV+)The (+) Transfer High Voltage is supplied to the Transfer Roller for transferringtoner onto the OPC Drum to the paper.■ Input Voltage: 24 VDC ± 15%■ Output Voltage: MAX +5.0KV ± 5% (duty variable)■ Line Regulation: under ± 3% (fluctuation input 21.6 V~27.6 V)■ Output Voltage Rising Time: 50 ms Max■ Output Voltage Falling Time: 100 ms Max■ Fluctuating Transfer Voltage with Environmental Various: 0 V~5 KV■ Environment Recognition Control Method: The THV-PWM ACTIVE istransfer active signal. It detects the resistance by recognizing the voltagevalue, F/B, while permits the environmental recognition voltage.■ Output Voltage Control Method: Transfer Output Voltage is outputted andcontrolled by changing duty cycle of THV/PWM signal.Charge Voltage (MHV)High voltage is supplied to the OPC drum through the charging roller whilecharging the skin of the OPC drum.■ Input voltage: 24 VDC ± 15%■ Output voltage: -1.2 KV ~ -1.8 VDC ± 3%■ Output voltage rising time: 50 ms Max■ Output voltage failing time: 50 ms Max■ Output control signal (MHV-PWM): CPU is HV output when PWM is Low.Cleaning Voltage (THV-)■ -1.2 KV ± 15%■ The (+) transfer voltage is not outputted because the THV PWM iscontrolled with high.■ The (-) transfer voltage is outputted because the THV-Enable Signal iscontrolled with low.■ The output fluctuation range is large because there is no feedback controland connection resistor.
