AR-FN2 (serv.man10). ARFN2 Service Manual-Circuit Descriptions - Sharp Copying Equipment Service Manual (repair manual). Page 13

This circuit controls rotation, stop, and rotating direction of DRM and the motor current. It is composed of the G/A (IC5), the constant-current
chopper system driver IC (IC6), etc. 
The G/A (IC5-57 

~

 60 pin) outputs the stepping motor drive excitement pattern signal to control the motor rotating speed and the rotating direction.

The PWM signal outputted from the G/A (IC 5-50 pin) is divided and integrated with R92, R87, and C63 to be converted into a constant voltage. The
converted voltage is inputted to IC6-9 pin and 11 pin to set the motor current value. The motor current value is controlled arbitrarily by varying the
ON DUTY of the PWM signal. 
C97-100 and C102 are for absorbing noises. C60 and C63 are for reducing sounds when the motor is held. C45 and C67 are for stabilizing the +5V
power. C65 of DSM is commonly used for stabilizing the ST +24V power. 

This circuit controls rotation, stop, and rotating direction of DTM and the motor current. It is composed of the G/A (IC5), the bridge circuit composed
of the FET (Q15 

~

 18), etc.

The motor rotation, stop, and rotating direction are controlled by the combinations of binary logic inputted from the CPU (IC9) to the G/A (IC5)
through the data bus. By this control, the control signal is outputted to the G/A (IC5-74 

~

 77 pin). 

These signals are inputted to the bridge circuit. 
C25, C26, and C104 

~

 C107 are for absorbing noises. 

Q7 and Q8 are used to turn on Q17 and Q18 respectively.
R75, R76, R81, and R82 are the dividing resistances used to obtain VGS of the FET. 
In addition, the following hard limit is provided for the rotating direction of TMM. 
CW direction (Bin UP): Document level sensor (PLS)
CCW direction (Bin DOWN): Tray limit sensor (TLS) 

Paper reverse motor
(DRM)

Paper reverse motor drive circuit

Bin shift motor drive circuit

Bin shift motor
(TMM)

11 – 11