| 摘要 |
PURPOSE:To accurately detect the rotational speed of the rotary machine by outputting an operation command signal only when the output voltage of an F/V converting circuit is between a 1st and a 2nd set voltage. CONSTITUTION:When the output voltage VA of an F/V converting circuit 36 which corresponds to the rotational speed of the rotary machine 25 reaches a 1st or 2nd set voltage V1 or V2, a 1st or 2nd detecting circuit 37 or 38 outputs a 1st or 2nd coincidence signal S1 or S2. Then a 1st or 2nd holding circuit 41 or 43 outputs an operation command signal with the coincidence signal S1 or S2 according to an increase signal SU or decrease signal SD outputted from a rotation state decision circuit 39. Therefore, the operation command signal can be outputted only when the output voltage VA from the F/V converting circuit 36 is between the 1st and 2nd set voltages V1 and V2. Consequently, even when the detection range of the rotational speed of the rotary machine 25 is narrow, that can accurately be detected. |
