| 摘要 |
PURPOSE:To detect a constant overload at all times without being subject to the effect of the magnitude of applied voltage by discriminating load as overload when pulses are not generated next before a timer interrupt time passes after the time of the preceding generation of pulses. CONSTITUTION:When an interrupt signal is generated at an earlier time than pulses are generated, a period tn+1 based on the current generation of pulses is measured at the step ST6, and a step ST7 is returned to a step ST3 while using the period tn+1 as a pre-period tn in the next cycle at the step ST7. When current pulses are not generated when the interrupt signal is generated, load fluctuation reaches an overload level, and a step ST5 proceeds to a step ST8. Accordingly, the measured period is compared with a discriminating value multiplied by a coefficient read on the basis of a pre-period measured at a time before by one step and the pre-period from prepared map data, and overload is discriminated, thus allowing the detection of overload not affected by the fluctuation of the applied voltage of a motor. |
