Preventing Rush Current - Canon CP660 Service Manual

• During standby, the temperature is controlled to 165°C.
• During printing, the temperature is varied to suit the selected fixing mode (Note).
Reference:
The voltage is highest in the reader unit while the scanner is moved in reverse during
printing operation with the reader unit installed. As such, the fixing heater is turned off.
Note:
Fixing Mode
The printer unit sets the target temperature for the upper/lower fixing roller as follows
according to the mode communicated by the printer board*
Color mode
Target temperature
Full-color
Mono-color
1
* Reader controller PCB (when making prints with the reader unit installed).
B.

Preventing Rush Current

The printer unit uses two heaters, and rush current would be appreciative if both
heaters were turned on at the same time.
In the light of this, the printer unit uses the expansion I/O (IC203) at time of power-on
to generate the rush current prevention drive signal (FXUONS) for the upper fixing heater
and the rush current prevention drive signal (FXLONS) for the lower fixing heater to turn
on the sub drive circuit for a specific period of time to suppress the current applied to the
heaters.
COPYRIGHT © 1999 CANON INC.
Download free service manual at http://printer1.blogspot.com
Plain paper Transpar-
mode ency mode
180°C 175°C
180°C 175°C
Table 6-201
CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 6 FIXING SYSTEM
1
:
Fixing mode
Thick paper Envelope
mode mode
175°C 185°C
175°C 185°C
Special fixing
mode
180°C
180°C
6-3