Canon NP6012 Service Manual page 72

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2. Turning On and Off the DC
Component
As soon as the Copy Start key is
pressed, the microprocessor on the DC con-
troller PCB sends the developing DC bias on
signal (DVDCON) to the microprocessor on
the composite power supply PCB.
In response, the microprocessor on the
composite power supply PCB drives the
main transformer (T102) to generate a DC
bias for the developing cylinder.
When the developing DC bias on signal
(DVDCON) from the microprocessor on the
DC controller is cut, the microprocessor on
the composite power supply PCB stops the
drive to the main transformer (T102), there-
by cutting off the DC bias.
COPYRIGHT © 1995 CANON INC.
CANON NP6012/NPGO12F /NP6212 REV. SEPT. 1995 PRINTED IN JAPAN (MPRIME AU JAPON)
3. Turning the AC Component On and
Off
About 3.5 sec after the Copy Start key is
pressed, the microprocessor on the DC con-
troller PCB sends the developing AC bias on
signal (DVACON) to the microprocessor on
the composite power supply PCB.
The microprocessor on the composite
power supply sends the AC bias oscillation
signal (ACBIAS) to the amplifier, which in
turn drives the transformer (T301) and gen-
erates an AC bias for the developing cylin-
der.
The AC output of the transformer (T301)
is transformed/rectified and then supplied to
the static eliminator.
When the developing AC bias on signal
(DVACON) from the microprocessor on the
DC controller PCB is cut off, the micropro-
cessor on the composite power supply PCB
stops the AC bias oscillation signal
(ACBIAS) to cut off the AC bias supply.
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