| 摘要 |
PURPOSE: To enhance the accuracy of measuring time in a motor control device of such a type of detecting a service interruption period of time by measuring the terminal voltage of a service interruption detecting circuit (CR circuit) constituted by the application of the discharge characteristic of a capacitor and of determining whether the operation before the service interruption is continued or not. CONSTITUTION: A switch circuit 4 for opening and closing a CR circuit 1 by a control signal from a controlling and computing means 2 is provided, and the CR circuit is charged and discharged through the switch circuit 4 at a predetermined point of time such as the time of shipping from a factory to obtain a standard discharge characteristic Vcs and a standard permissible level voltage VS corresponding to permissible level time TSR in which the continuation of the operation of a controlled system after the recovery of service interruption is allowed, is obtained and stored into a nonvolatile memory means 3. At the point of time when service interruption is detected, an actual charge voltage Vcm which is the terminal voltage of the CR circuit 1 is stored into the nonvolatile memory means 3, and at the point of time of the recovery of service interruption, an actual permissible level voltage VCR computed from the actual charge voltage Vcm the standard discharge characteristic Vcs and the standard permissible level voltage VSR is compared with the terminal voltage of the CR circuit 1 immediately after the recovery of service interruption to determine whether the operation is continued or not. |
