Samsung ML-3471ND/XAX Service Manual page 30

DC FAN / SOLENOID Driving
It is driven by transistor and controlled by D14(FAN MAIN), E16(FAN DUPLEX), C23(PICK-UP CLUTCH), C18(REGI
CLUTCH), D15(MPF CLUTCH) of CPU.
When it is high, the fan is driving by turning on the TR, and it is off when the sleep mode is selected. There are three
solenoids, and they are driven by paper pick-up, regi and MPF signal. It is turned on or off by C23, C18, D15 of CPU. The
diode protects the driving TR from the noise pulse, which is flown when the solenoid id de-energizing.
FAN Driving Circuit is driven by Transistor, and controlled by D14, E16 of CPU.
Motor Driving
The main motor driving circuits is on the BLDC Motor Ass y Unit. Main Controller has the interfacing circuits. There is
motor driver IC on the motor control board of Motor Ass y Unit.
The exit motor driving circuits is formed when the driver IC is selected. The AN44060A Motor Driver IC is used in this
case. The resistance Rs value for sensing and voltage value for the V reference can be changed by motor driving voltage
value. The motor driving voltage is calculated with the following formula.
IN 0, 2 IN 1, 3
L L
H L
L H
H H
The motor driving circuit is formed when the Driver IC is selected. The A3977 Motor Driver IC is used in this case. The
resistance Rs value for sensing and voltage value for the V reference can be changed by motor driving voltage value. The
motor driving voltage is calculated with the following formula.
I = Vref / Rs, wherein Vref is (R1 5V) / (R1+R2).
Samsung Electronics
Output Current
Vref / (10*Rs) = Iout
Vref / (15*Rs) = Iout * 2/3
Vref / (30*Rs) = Iout * 1/3
0
Product specification and feature
Service Manual
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