Printronix L5535, Maintenance Manual

Page: 233 / 358

High-Voltage (Corona) Power Supply
II–233
Cleaning Bias Remote ON/OFF
This signal turns on or off the bias voltages supplied to the drum cleaner.
There are two bias voltages controlled by this signal: the semiconducting
brush bias voltage (–V2), and the recovery roller bias voltage (–V1). A
variable resistor (B type) sets the magnitude of the recovery roller bias
voltage (–V1) to between –200 V and –400 V. The semiconducting brush bias
voltage is 0.47 times the recovery roller bias voltage.
Developing Bias Remote ON/OFF
This signal turns on or off the voltage applied to the developing roller.
The voltage applied to the developing roller consists of an AC voltage
superimposed onto a constant DC voltage. A variable resistor (B type) sets
the magnitude of the AC component of this voltage to between 1 KV and 2 KV
P-P at 10.5 KHz. A signal from the MC board to the high-voltage power supply
(the developing bias control signal) sets the magnitude of the DC component.
Developing Bias Control
The developing bias control signal sets the voltage of the DC component
applied to the developing roller, based on data that the MC board obtains from
the controller.
As the voltage of the developing bias control signal varies from 0 V to +12 V,
the DC component of the voltage to the developing roller varies from +200 V
to +600 V.
Alarm
The alarm signal is an open collector signal from the high-voltage power
supply to the MC board. If the high-voltage power supply detects a problem
with any of its power supplies mentioned above, it asserts the alarm signal. A
problem is defined as a no-load output condition or a short circuit output
condition in any of the power supplies (except for the drum cleaner supplies,
which are monitored only for the short circuit output condition).
Signal System Ground
This is the reference for the remote control signals mentioned above.
Drive Power Supply
This is the +24 V drive power supply.
Drive System Ground
This is the reference for the drive power supply signals mentioned above.