| 摘要 |
PURPOSE:To prevent overcurrent due to electric conduction at the time of holding by repeatedly ON-OFF operating the switches of each phase at time intervals shorter than a specified holding time and intermittently supplying voltage when a stepping motor(SM) is held temporarily under a stopped state. CONSTITUTION:When an SM 1 is stopped temporarily for reverse rotation, a CPU 7 outputs a stop signal to a driver 6. The driver 6 repeatedly ON-OFF operates the switches of specified each phase at time intervals shorter than a specified holding time. Consequently, the coils of each phase are supplied intermittently with voltage from a high voltage power supply 8. As a result, a rotor can be held and stopped at a constant position. When a conduction holding time is 30ms, ON-OFF operation of 1ms is repeated fifteen times. Accordingly, a time when electricity is conducted through the coils of each stator is halved substantially even in a power supply, to which high voltage is applied from the high voltage power supply 8, thus preventing the outflow of overcurrents due to electric conduction at the time of holding. |
