| 摘要 |
PURPOSE:To obtain a control circuit limited in the current consumption with a simple circuitry by controlling the supply of power to a bridge circuit including an armature of a motor to control the speed in one side thereof with ON or OFF operation of a transistor. CONSTITUTION:A bridge circuit 1 is made up of resistances 2-4 and an armature 5 and connected to a D.C. power source 6 by way of an inductance 8 and a power supply controlling transistor 7. First and second control transistors 12 and 15 are controlled with a transistor 10 for detect an reverse extra-voltage to effect an ON/ OFF operation of a transistor 7. Therefore, when the revolutions of a motor is low, the transistor 7 is turned ON to supply power to the bridge circuit 1 and the revolutions thereof increases, the transistors is turned OFF while a counter electromotive force of the inductance 8 causes current to run to the bridge circuit 1 through a diode 18. The repetition of this procedure enables the control of the revolution of the motor. |
