| 摘要 |
PURPOSE:To protect a semiconductor, etc., positively by stopping the operation of servo amplifier when the time during which load currents of a specified value or more flow exceeds a fixed value. CONSTITUTION:A speed control circuit 1 receives a speed command VC, and outputs a current command IC. A power amplifier 2 controls a PWM circuit composed of a semiconductor 3 in response to the current command IC. A speed signal from a speed detector 5 and a current signal detected by a current detector 6 are fed back to the speed control circuit 1. When load currents exceed a fixed value at that time, the time is measured by a timer in the speed control circuit 1. When the state of overcurrents continues for an appointed time or more, the current command IC is turned OFF while an alarm signal AL is output. |
