| 摘要 |
<p>PURPOSE:To prevent a back current of motor current to the electric power source side by a method wherein one side of switching elements forming a pair out of four switching elements formed in bridge construction is made to perform chopping action, and another side is made to remain in ON condition as it is. CONSTITUTION:Transistors 3-6 and diodes 8-11 are connected to a rectifying circuit 1 in bridge connection, a DC motor 7 is connected to the nodes thereof, while bases of the transistors 3-6 are controlled to ON and OFF by control circuits 12, 13 to make the motor 7 to perform forward and backward running. At this time, a control signal for performance of chopping is applied to one side of the transistors 3, 4 forming a pair, and the prescribed DC voltage is applied to another side to make it to remain in ON condition as it is to perform control. Accordingly a wheeling circuit can be formed for the motor current in the OFF period, generation of back current of the motor current to the electric power source side can be prevented, and moreover smoothing of the motor current can be attained and enhancement of performance can be attained.</p> |
