Drum Charge - Gestetner A294 Service Manual

DRUM UNIT

2.5.5 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 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 charge/bias/grid power pack [A] gives a constant corona current to the corona
wires (–1,200 µA).
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. This is described in the Process Control section in
more detail.
A294/A295
CÓPIA NÃO CONTROLADA
[A]
2-48
CÓPIA NÃO CONTROLADA
A294D203.WMF
SM