Other Controls - Canon LBP-1000 Service Manual

F. Other Controls
1. Fan motor control
This printer has a fan motor as a cooling (air inlet) fan.
Figure 2-2-10 shows the fan motor control circuit.
Engine controller PCB
CPU
FANSTOP
26
FANON
47
IC402
FLOCK
48
The fan motor is a DC brushless motor with built-in hall elements, and is unified with the motor
drive circuit.
At the same time as start of main motor drive, the CPU (IC402) sets the FANSTOP of No. 26
pin to "H" and rotates the fan motor at its full speed by setting the FAN DRIVE signal (FANON)
to the voltage level of full-speed rotation.
The CPU switches the fan motor drive from full-speed rotation to half-speed rotation by set-
ting the FANON of No. 47 pin to "L" and reducing the FANON signal to the voltage level of half-
speed rotation.
The fan motor rotates at its full speed while the main motor is rotating and for 30 seconds
after the main motor stops. In other periods, the fan motor repeats full-speed rotation, half-
speed rotation, and stop in that order.
The CPU assesses a fan motor failure and reports it to the video controller when the FAN
LOCK DETECTION signal (FLOCK) stays "H" for 10 seconds or more continuously while the fan
motor is rotating.
+24VA
FANON
J401-20
+3.3V
J401-19 FLOCK
Figure 2-2-10
CHAPTER 2
Intermediate PCB Cooling fan
FAN1001
J1001-8 J1005-1
J1001-9 J1005-2
J1005-3
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