초록 ▼

A motor speed control system controls the rotation speed of the motor in accordance with the pulse width of a speed control pulse signal applied to the motor speed control system. The speed control pulse signal is not directly applied to the motor, but is converted to a voltage signal having a volta

A motor speed control system controls the rotation speed of the motor in accordance with the pulse width of a speed control pulse signal applied to the motor speed control system. The speed control pulse signal is not directly applied to the motor, but is converted to a voltage signal having a voltage level which corresponds to the pulse width of the speed control pulse signal. The converting system includes a charge/discharge circuit for varying a charge voltage level of a capacitor in accordance with the differences of the actual rotation speed of the motor and the desired rotation speed of the motor represented by the speed control pulse signal. The charge voltage level stored in the capacitor is applied to the motor to drive it.

대표청구항 ▼

A motor speed control comprising: a motor; means for sensing the rotational speed of said motor; means responsive to said sensing means for developing a motor speed pulse signal including a series of pulses having a pulse width which varies in response to the sensed rotational speed of said motor; c

A motor speed control comprising: a motor; means for sensing the rotational speed of said motor; means responsive to said sensing means for developing a motor speed pulse signal including a series of pulses having a pulse width which varies in response to the sensed rotational speed of said motor; converting means responsive to said pulse signal produced by said developing means for developing a voltage signal having a voltage level corresponding to the pulse width of said series of pulses; drive means responsive to said voltage signal produced by said converting means for amplifying said voltage signal and driving said motor, said drive means including, first and second transistors having controlled terminals commonly connected together and to a first terminal of said motor, the bases of said transistors being commonly connected to said converting means to receive said voltage signal, said first transistor applying a drive voltage to said first terminal to drive said motor, said second transistor conducting to brake said motor by absorbtion of counter electromotive force when said voltage signal is at a level lower than the level indicative of the desired motor speed.