Canon NP6218 Copier User Manual


 
C. Controlling the Supply Power for the Fixing Heater
The temperature of the fixing heater is controlled by controlling the power supplied
to the fixing heater.
The resistance of the plane-shaped heater used as the fixing heater may show some
variation depending on which production lot it comes from.
For this reason, whenever you have replaced the copier’s heater, you must store the
resistance value in service mode (No. 304; see p. 10-31); this way, the microprocessor
on the DC controller PCB can exert proper control over power.
Caution:
The resistance of the fixing heater is stored in service mode at the time the copier
is shipped out of the factory; do not change it unless you have replaced the fixing
heater.
The power of the fixing heater is controlled by a phase power control method.
The microprocessor controls the output timing of the fixing heater drive signal
(HTRD) so that power that suits the target temperature of the fixing heater may be
supplied to the heater (potential control of the supply power).
Figure 6-104
COPYRIGHT
©
1997 CANON INC. CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 6 FIXING SYSTEM
6-5
HTRD
Supply power
to heater