| 摘要 |
PURPOSE:To prevent an irregular hand advance due to erroneous drive of a stepping motor securely by detecting an impact and applying a braking pulse to the stepping motor. CONSTITUTION:On detecting a load such as an impact, an impact detecting means 7 outputs an impact detection pulse, which is synthesized by a waveform synthesizing part 3 with a drive pulse from a frequency dividing circuit 2 to generate the braking pulse. This pulse is discriminated from the drive pulse by a drive pulse applying means 4 and applied to the stator of the stepping motor 6 through a drive part 5 to lock the rotation of the rotor electromagnetically, thereby preventing the rotor from rotating to an unstable point owing to the impact, etc. Thus, an irregular hand advance due to the erroneous drive of the stepping motor caused by an impact, etc., is prevented accurately. |
