Drum Surface Potential Control - Printronix L5000 Series Maintenance Manual

Drum Surface Potential Control

To assure that the main charger produces a constant potential on the drum surface, the
printer measures the drum surface potential between the photoconduction and
developing sections. The printer controls the current flow to the main charger in
accordance with the difference between the measured drum surface potential and the
target potential value stored in the EEPROM of the CPU. The EEPROM value is set
through the operator control panel, "Drum Surface Voltage" setup command.
Control panel
The potential measurement circuit actuates 400 msec after the main charger turns
ON. It subsequently actuates at 400 msec intervals until the main charger turns OFF.
(Note, however, that the surface potential target value (Vc) which is selectable from
the panel, etc., ranges from above 45 V to below 70 V [45 V < Vc < 70 V], and that
the current flow to the main charger (I) ranges from above 0 A to below 127 A [0 A
< I < 127 A].)
Principles of Operation 5–49