| 摘要 |
PURPOSE:To reduce a variation in current flowing into a Hall element and to stabilize the rotation of a motor by a method wherein the Hall element and a transistor controlled by the counter electromotive force of motor coils are connected in parallel and a constant current is supplied to the Hall element and the transistor. CONSTITUTION:A current limiting resistor 2 and a Hall element 3 are connected in series with a power supply 1 and the output terminals of the Hall element 3 are connected to the driving coils 6, 7 of a motor 13 through transistors 4, 5. And a control transistor 8 is connected to the opposite ends of the Hall element 3 and the base is connected to a feedback resistor 18 through a time constant circuit consisting of a resistor 11 and a capacitor 12. Therefore, the current flowing into the Hall element 3 is controlled by the current in the transistor 8 controlled by the counter electromotive force produced on the coils 6, 7, so the rotation of the motor can be stabilized by reducing a variation in the current in the Hall element 3 and a variation in the resistor of the Hall element 3 can easily be corrected by adjusting time constant. |
