| 摘要 |
PURPOSE:To enable the high output of a motor and the driving by great current, by reducing the base current of an output transistor, when a counter electromotive force or output voltage like induced voltage coming from the rotational frequency of the motor is heightened by the reactance component of a motor winding. CONSTITUTION:From a transistor Q2, the base current of an output transistor Q1 is fed, and by a transistor Q3 and a resistor R2, the base voltage of the transistor Q1 is detected. When the collector current of the output transistor Q1 is increased and the base voltage is heightened, by the circuit of the transistor Q3 and the resistor R2, the base current of the transistor Q2 is absorbed, and the base current of the output transistor Q1 is reduced, and the collector current is limited. When the collector voltage of the output transistor Q1 is heightened, then the current of a bias circuit consisting of transistors Q4...Q5 and resistors R3...R4 is determined. The current is current-millered by the transistor Q3, and the base current of the transistor Q2 is absorbed, and the collector current of the output transistor Q1 is limited. |
