Gestetner A294, Service Manual

Page: 90 / 600

DRUM UNIT
A294/A295 2-40 SM
V
G
Adjustment
The potential on unexposed areas of the drum (V
D
) gradually changes during drum
life. To keep V
D
constant, the grid voltage (V
G
) is adjusted during process control
initial setting.
The BCU checks V
D
using the drum potential sensor [A]. If it is not within the target
range (–900 V
±
20 V), the BCU adjusts V
G
(Grid Voltage) through the
charge/bias/grid power pack to get the correct target voltage.
The most recently detected values can be displayed with SP3-902-2 (V
D
) and 3-
902-4 (V
G
).
If the CPU cannot get V
D
within the target range by changing V
G
, V
G
is set to the
value stored in SP2-001-01 and LD power is set to the value stored in SP2-103.
Then SC312, SC313, or SC315 is logged.
Charge/Bias/Grid
P . P
B C U
A294D642.WMF
[A]
CÓPIA NÃO CONTROLADA
CÓPIA NÃO CONTROLADA