| 摘要 |
PURPOSE:To make it possible to hold a braking effect until the motor speed becomes zero when a rotating DC motor is brought to a halt with a semiconductor device after a power is shut down. CONSTITUTION:While a motor M is rotated at high speed before or after the power supply 2 is turned off, a capacitor in a power supply circuit is charged with electricity, and braking is applied with an inductive voltage of the motor. The energy stored in the capacity is held as it is until the terminal voltage VM is lowered up to a voltage, in which the semiconductor device in the braking circuit 4 can not provide a braking effect on the motor. When the braking effect by the inductive voltage is run out, the energy stored in the capacity is provided to the semiconductor braking circuit 4 so that the braking effect is effective to the motor M even at a rotation rate of zero. |
