Canon PC300 Service Manual page 45

BSS OPERATIONS AND TIMING Sie SS CE
XN
Operations
HVPDC=1, HVPHO=1 (copying)
DC bias control circuit set to '-600 V'.
Transformer T106 generates 'DC bias'.
HVPAC=1
Oscillation control circuit goes ON.
Transformer T103 generates AC bias
Primary charging
———+ (DC bias + AC bias) goes ON.
HVPDC=1, HVPHO=0 (document not exposed)
DC bias control circuit set to '-240 V'.
Transformer T106 generates DC bias.
HVPAC=1
Oscillation control circuit goes ON.
Transformer T103 generates AC bias.
Primary charging
—— (DC bias + AC bias) goes ON.
HVPDC=0, HVPHO=0 (standby)
DC bias control circuit goes OFF.
Transformer T106 DC bias goes OFF.
HVPAC=0
Oscillation control circuit goes OFF.
Transformer T103 goes OFF.
Primary charging
———> (DC bias + AC bias) goes OFF.
3-18 COPYRIGHT © 1994 CANON INC. CANON PC300/920/325, FC210/220.REV.0 JULY 1904 PRINTED IN JAPAN (IMPRIME AU JAPON)