Canon CLBR 460ps Service Manual page 93

6. Fan motor control
The printer has two exhaust fans(90-fan and 60-fan) and one inducting fan(40-fan).
These three fans work for exhausting air, exhausting heat and cooling air in the printer.
The control circuit of each fan motor is shown below.
90FANHF
D-CPU
(IC1001) /40FANRDY
90FANON
/90FANRDY
Gate array /60FANRDY
(IC1003)
40FANON
40FANNC
The fan motor is a DC brushless motor containing a hall element and has the motor driver cir-
cuit in it.
When the power is turned ON, the D-CPU controls the gate array to set 90FANON to "H." As
a result, the 90FAN DRIVE signal (/90FAN24V) and 60FAN DRIVE signal (/60FAN24V) are set
to "L" and the 90-fan and 60-fan are rotated. The 90-fan is rotated at its half speed by the
90FAN HALF SPEED signal (90FANHF) output from the D-CPU until the print operation starts.
(Note 1)
At power-ON, 40FAN DRIVE signal (40FANON) is also set to "H." As a result, the 40FAN
DRIVE signal (/40FAN24V) is set to "L" and the 40-fan is rotated.
After power-ON, the 90-fan and 60-fan rotate regardless of door open/close condition. The
40-fan stops rotation when the drum cartridge drawer is open as the connector (J77-3) is dis-
connected and the /40FAN24V is interrupted when the drawer is open. The connector J77-2 is
also disconnected by the drawer open. When the D-CPU detects the 40FAN NO CONNECT sig-
nal (40FAN N.C.) "H" via IC1003, it notifies the video controller of the "40fan no contact." (Note
2)
When the fan motors are rotated at the specified speed, the 90FAN READY signal (/90FAN-
RDY), 60FAN READY signal (/60FANRDY), 40FAN READY signal (/40FANRDY) are "L."
The D-CPU performs the fan lock detection periodically while the fan motors are rotating.
When the D-CPU detects any of the signals, /90FANRDY, /60FANRDY, or /40FANRDY being "H"
DC controller PCB
+24V
J1005
-4
-2
-1
-5
+5V
-3
-6
+5V
+24VA
J1022
-2
-3
-1
-4
Figure 2-2-27
Developing PCB
J202 J209
90FANHF
-3 -4
/90FAN24V -5
-3
PGND -6
-1
/90FANRDY
-2 -2
J208
/60FAN24V -4
-3
/60FANRDY
-1
-2
-1
J77
/40FANRDY
-4
/40FAN24V -3
PGND -1
40FANNC
-2
CHAPTER 2
90-fan
FAN1
60-fan
FAN2
40-fan
FAN3
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