| 摘要 |
PURPOSE:To raise a response property during speed shifting and to raise the resolution during a normal operation by providing a mode discriminator for comparing the frequency command of an analog amount with a frequency output to decide a counting period in response to the mode. CONSTITUTION:A frequency command fi applied as an analog amount from an exterior is converted by a frequency converter 10, and output as a clock output 10a to a counter 20. When the output frequency f0 of an inverter and a frequency command fi at frequency discriminating time are larger than the prescribed frequency deviation epsilon, a counting period is set in a timer 30, and the result for counting the period is output to a frequency delay circuit 40. The frequency f0 is compared by a mode discriminator 50 with the command fi, and when the difference is the prescribed deviation or lower, it is judged to shift to substantially normal mode to switch the set time of the timer 30. |
