APPLYING DEVICE OF LARGE MOTOR STOPPING TORQUE TO DC MOTOR

摘要

PURPOSE:To obtain large motor stopping torque by reversing power source polarity by means of an astable multivibrator, and setting its repeating frequency higher than the maximum frequency that a DC motor can respond. CONSTITUTION:When points A and C of switches 4 and 5 are closed, a DC power source 3 is applied to an electric motor 1 to rotate it. In order to stop the motor, the points of the switches 4 and 5 are switched to points B and D. Then voltage of the source 3 is applied to a circuit 6 that reverses the power source polarity at a required frequency. In the circuit 6, an astable multivibrator 8 operates through a resistor 7, and its output frequency is set much higher than the maximum frequency that the DC motor can respond. As a result, the power source polarity is reversed and a rotor is forcibly locked.