2-Speed Control; Sequence Of Operation - Canon imageRUNNER 2270 Service Manual

10.3.2 2-Speed Control

The rotation of the 2 fans used in the machine is controlled to 2 different speeds by the
voltage switchover circuit of the individual fans.
DC controller PCB
CPU
F-10-3

10.3.3 Sequence of Operation

1. Standby Mode, Sleep Mode
In standby mode or sleep mode, the heat discharge fan (front, rear; FM1/2) is at rest.
2. Printing
While printing is under way, the fans are switched between full speed and half speed
depending on whether the machine is in full speed mode or half speed mode and the reading
of the environment sensor (HU1).
- Double-Side Printing
Environment sensor (HU1) reading
25 deg C or more
Less than 25 deg C
24V
Full-speed
signal
Voltage
Half-speed
switching circuit
signal
13V
24V or 13V
Clock signal
T-10-4
Full speed, half speed
Full speed
Half speed
Chapter 10
0006-5389
Fan
0006-5390
10-7