Phaser 3140/3155/3160 Printer Service Manual
2-13
Theory of Operation
•
Environment Recognition Control Method: The THV-PWM ACTIVE is the
transfer active signal. It detects the resistance change of the transfer roller
(due to environmental changes) which alters this voltage feed-back signal. For
more information, see “Transfer” on page 2-18.
•
Output Voltage Control Method: The Transfer Output Voltage is output and
controlled by changing the duty cycle of the THV/PWM signal.
Charge Voltage (MHV)
High voltage is supplied to the OPC drum through the charging roller while
charging the skin of the OPC drum.
•
Input Voltage: 24 VDC ± 15%
•
Output Voltage: -1.0 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 output because the THV PWM is controlled
with high.
•
The (-) Transfer Voltage is output because the THV-Enable Signal is controlled
with low.
•
The output fluctuation range is large because there is no feedback control and
connection resistor.
Developing Voltage (DEV)
The Developing Voltage is supplied to the Developer Roller to transfer to the toner
to the charge on the OPC Drum scanned by the laser beam while printing the
image. The engine controls whether the high voltage is supplied and its quantity.
•
Input voltage: 24 VDC ± 15%
•
Output voltage: -200 V ~ -600 V DC ± 3%
•
Output voltage fluctuation range: PWM control
•
Input contrast of the output stability degree: ± 3% or less
Loading contrast: ± 3% or less
•
Output voltage rising time: 50 ms Max
•
Output voltage falling time: 50 ms Max
•
Output Control Signal (BIAS-PWM): The CPU output is HV output when PWM
is low.
