JPS5713371A - Power counting device for alternating current generator - Google Patents

Abstract

PURPOSE:To enable the simple and high-precise counting of a power of an A.C. generator, by a method wherein an integrating value at every period of a linear current is sampled by means of a signal being equivalent to a phase difference between the linear current and a phase voltage. CONSTITUTION:A linear current Ia of a generator 1, detected by a current transformer CT, is supplied to an integrating circuit 10 to integrate it at every one period, and is converted into a cosine wave signal which surges in only a positive direction. Meanwhile, a linear voltage Vab, detected by a transformer PT, and the linear current Ta from the integrating circuit are applied to an AND gate 23, and a phase difference signal i is inputted as an up mode to a counter 24. The counter 24 is changed over to a down mode at a point of time when up-counting is completed, and when the contents to go a 0, an FF27 is reset. A switch circuit 32 is opened through the output of the FF27, and the output of the integrating circuit 10 is sampled and is held in a capacitor C6. This permits easy counting of a power without the use of a multiplier.