| 摘要 |
PURPOSE:To drive a carriage stably with high speeds by providing a phased locked loop to which is added feedback loop of frequency modulation type for a reference oscillator consisting of a low-pass filter and a differential circuit and a polarity change-over circuit for applied voltage to DC motor. CONSTITUTION:When a set speed signal 24 is input, the output frequency of an oscillator 1 is varied. In case where input set speed is greater than the set speed before changing, the phase forward signal 8 of a phase detector 2 is output, converted into analog signal 11 through a low-pass filter 9, and further converted into a false acceleration signal 12 by a differential circuit 10. The output signal of a reference oscillator 1 is modulated in frequency by the signal 12, resulting in the rise of the speed of the motor 4. On the other hand, when the set speed signal 24 is set in a small magnitude, a flip-flop 23 for braking is set, the electrifying direction of the motor 4 is varied, and the motor 4 is braked and decelerated quickly. |
