| 摘要 |
A drive circuit of a brushless motor including a search coil L1 and a drive coil L2 comprises a Schmitt trigger circuit formed by a first operational amplifier OP1 which detects rotation of the motor by the search coil L1, and an oscillator circuit formed by a second operational amplifier OP2 which functions as an inverter during rotation or as a rotation stoppage signal-delivering section during stoppage of the motor. The drive coil L2 alternately is driven by the first operational amplifier OP1 and the second operational amplifier OP2. In case of a stoppage of the motor the second operational amplifier OP2 delivers an oscillating signal to the outside. <IMAGE> |
