| 摘要 |
PURPOSE:To enable a brushless motor to be operated at a low voltage and with a small current, by forming said driving circuit by combining NPN and PNP transistors. CONSTITUTION:The input of a rotor position-detecting part is supplied to the connecting point A between the bases of an NPN transistor TR41 and a PNP transistor TR43 which are connected in an emitter follower connection manner, while the output of a control signal-exchanging part 38 is supplied to the respective collectors thereof. Moreover, the outputs of the transistors TR41 and 43 are supplied to the combination of an NPN transistor TR47 and a PNP transistor TR50 and the combination of a PNP transistor TR51 and an NPN transistor TR51 respectively, each of said combinations being formed in a Darlington connection manner. Then, the connecting point B between the collectors of the respective transistors TR50 and TR51 is connected to the coil of a motor. Because a driving circuit 33 is formed by thus combining the NPN and PNP transistors, said circuit can be operated at a low voltage as well as with a small base current. |
