| 摘要 |
PURPOSE:To obtain a control circuit by supplying power through a switching transistor to a bridge circuit having a motor and resistors and controlling the output of an error amplifier, thereby reducing Joule heat. CONSTITUTION:A series circuit of a transistor 2, a coil 3 and a condenser 4 is connected to a DC power source, and a bridge circuit having a motor 6 and resistors 7-9 is connected across the condenser 4. A Schmitt trigger which includes transistors 14, 15 controls the transistor 2, and an error amplifier 27 which has a transistor 10 and a diode 11 is provided, thereby controlling a transistor 22 with the output. Accordingly, the upper and lower slice levels of the Schmitt trigger are varied by the output of the amplifier 27, thereby controlling at the constant speed, and Joule heat is controlled to be extremely small by switching the transistor 2. |
