| 摘要 |
PURPOSE:To obviate FG detector of a magnet, a coil etc., by a method wherein analog position detection signal of a rotor detected by a Hall element is converted into binary signal, and then inputted as feedback gain (FG) signal into PLL control circuit. CONSTITUTION:A Hall element motor has three-phase exciting coils 7a-7c, and pole number of its rotor is six. Among Hall elements 8a-8c to detect the rotational position of the rotor of the motor, analog position signal detected by one Hall element 8c is inputted to a wave shaping circuit 14 of open collector type and converted into binary signal. Output signal of the wave shaping circuit 14 is inputted as FG signal of rotational speed of the Hall element motor into PLL control circuit 1. |
