초록 ▼

A speed control device for direct current motors comprises a tacho generator which generates signals corresponding to the rotating speed of a motor, a reference signal generating device to regulate the rotating speed of a motor uniform, a deviation detector for these signals, a comparison wave gener

A speed control device for direct current motors comprises a tacho generator which generates signals corresponding to the rotating speed of a motor, a reference signal generating device to regulate the rotating speed of a motor uniform, a deviation detector for these signals, a comparison wave generator and a control device, the temperature characteristics of said tacho generator are offset by temperature compensating means, such as a diode arrangement whose characteristics correspond to the temperature characteristics of the tacho generator and which moves the errors introduced by the tacho generator.

대표청구항 ▼

A speed control system for a direct current motor, comprising a DC tacho-generator for generating a speed indicating signal normally proportional to the speed of the motor, signal level adjusting means for producing an output proportional to the signal generated by said DC tacho-generator, reference

A speed control system for a direct current motor, comprising a DC tacho-generator for generating a speed indicating signal normally proportional to the speed of the motor, signal level adjusting means for producing an output proportional to the signal generated by said DC tacho-generator, reference means for forming a reference signal, differential amplifier means having a first input terminal connected to the output from said adjusting means and a second input terminal connected to the signal from said reference means producing an error signal that corresponds to a difference between the output of said adjusting means and the signal from said reference means, waveform-producing means for producing a varying signal of a predetermined wave shape, comparison means responsive to said waveform-producing means and the error signal from error signal-producing means for comparing the error signal with the wave shape of said waveform-producing means for producing pulses which last as long as the relationship between the wave shape and the error signal is in one range and outside another, switching means coupled to said comparison means and responsive to the pulses therefrom for producing driving pulses having pulse widths determined by said comparison means, the speed indicating signal departing from normal proportionality to the motor speed in response to changes in temperature, said reference means having a coNstant voltage circuit including a constant voltage circuit including series-connected diodes which departs from a constant value at a rate corresponding to the rate at which the speed indicating signal departs from proportionality to the motor speed.