Canon GP335 Service Manual page 138

CHAPTER 6 IMAGE FORMATION SYSTEM
4. Correcting the Application Voltage Level (ATVC control)
The transfer charging efficiency varied according to changes in humidity or deterioration of the
transfer roller. A reference current is applied each time the Copy Start key is pressed to measure the
degree of voltage output for correction as follows:
A reference current is applied during initial rotation after the Copy Start key is pressed.
The transfer voltage is detected and returned to the PW-CPU on the composite power supply
PCB.
The PW-CPU computes an optimum application voltage.
Transfer charging is started using the optimum application voltage.
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COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)