| 摘要 |
<p>PURPOSE:To make highly accurate detection possible by switching operational elements through a method of moving averages between a detection of a three product method and an effective value detection in accordance with the range of variations in constituent elements of an object to be detected such as a generator. CONSTITUTION:In a detected input switching device for an A.C. generator, a main operation control section 20 converts a scan output from a multiplexer 15 into a digital signal by means of an A/D converter 21, and this digital signal is then inputted to a CPU 22 and RAMs 25a and 25b. A timer circuit 24 causes sample-and-hold circuits 14a-14c of a detected input circuit 10 to effect sampling. A CPU 22 causes a switch instruction circuit (D/O) 27 to switch change-over switches 13a and 13b to the A.C. instantaneous value side thereof when the frequency of a generator falls within a rated frequency of + or -3Hz, but, in any other cases, causes that circuit to switch the switches to the effective value converting circuit side thereof. To switch an A.C. instantaneous value input to an effective value input, and vice versa, half cycles of an alternating current are subjected to moving average for six samples, whereby the amount of a detected input is obtained. Hence, highly accurate operation of detection is possible.</p> |
