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THEORY OF OPERATION
2-2-5. Paper Feed Motor Driving Circuit
Again, a stepping motor is employed as the paper feed motor, which turns a certain angle only when a drive pulse is
received. This 4-phase stepping motor is controlled by the phase 1-2 excitation method. The following is the description
of the paper feed motor drive circuit and the control signal generated by the phase 1-2 excitation method.
Fig. 2-11 Paper Feed Motor Driving Circuit
Fig. 2-12 Paper Feed Motor Driving Signals
The utilization of voltage applied to the paper feed motor is described as follows.
Mode Voltage Application
Operation +24V Motor Drive
Standby: +5V Holding Bias
Voltage to the paper feed motor is changed by setting CPU port P31 to LOW or HIGH and by turning transistors TR7 and
TR2 ON or OFF.
When TR2 is turned on, +24V is applied to the paper feed motor.
When TR2 is turned off, +5V is supplied to the motor via diode D2.
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