Canon imageRUNNER 2270 Service Manual page 404

Chapter 9
9.3.2.3 Controlling the Power Supply at Start-Up
When the thermistor detection temperature is 180 deg C or less, the power control to
compensate for the heater, (varying according to input voltage and a heater resistor value)
is performed so as to raise the temperature of the fixing unit to the required temperature for
fixing in a short time.
1. starts 65% power supply.
2. uses thermistor reading = T1 (deg C) occurring 400 msec after the start of 65% power
supply.
3)uses thermistor reading = T2 (deg C) occurring 500 msec after the start of 65% power
supply.
4. computes the difference between T2 and T1, refers to a power supply ratio table to
compute a power supply ratio X (%), and uses the result.
5. uses the thermistor reading = T3 (deg C) occurring 200 msec after the start of X (%)
power supply.
6. uses the thermistor reading = T4 (deg C) occurring 300 msec after the start of the X (%)
power supply.
7. computes the difference between T4 and T2, refers to a power supply ratio table,
computes a power supply ratio Y (%), and uses the result.
8. repeats step 5 through 7 until the start-up control target temperature is reached.
9. when the start-up control temperature is reached, shifts to copying temperature control.
180
85
9-6
C D
200ms
400ms
500ms 300ms
B
A
E
F-9-3
0006-6583