Drum Charge - Gestetner B070 Service Manual

DRUM UNIT

6.11.3 DRUM CHARGE

Overview
This copier uses a double corona wire Scorotron system to charge the drum.
Because of the high speed of this copier, two corona wires are needed to give a
sufficient, uniform negative charge to the drum surface. The stainless steel grid
plate makes the corona charge uniform and controls the amount of negative charge
on the drum surface by applying a negative voltage to the grid.
The CBG (Charge, Bias, Grid) power pack [A] supplies a constant corona current
to the corona wires, –1600 µA for Photo mode and –1400 µA for all other modes
(Text, Text/Photo, Pale, Generation Copy).
The voltage to the grid plate is automatically controlled to maintain the correct
image density in response to changes in drum potential caused by dirt on the grid
plate and charge corona casing. (!6.11.8)
B070/B071
CÓPIA NÃO CONTROLADA
[A]
6-58
CÓPIA NÃO CONTROLADA
B070D203.WMF
SM