| 摘要 |
PURPOSE:To convert a power factor signal in an AC circuit containing an advance/delay signal directly into a DC signal proportional thereto, by using a multiplication/division computing circuit in a circuit for determining a ratio between a power P and a reactive power Q to make Y as the parameter of Q/P. CONSTITUTION:An effective power P is drawn at an output end of a switch S1 to be applied to an amplifier A1. A reactive power Q' is obtained at an output end of a switch S2 to be applied to an amplifier A2. A multiplication/ division circuit M2 performs a computation of tanphi=(Q/P).VP (fixed) based on the effective power P and a reactive power Q from the amplifier A3 and the results are applied to an absolute value circuit BC to obtain an absolute value ¦Q/P¦ thereof, which is applied to a frequency conversion circuit FC. However, a multiplication/division circuit M1 computes tanphi=(Q/P) to obtain a voltage V0. An output circuit OUT is made up of an amplifier A5, a transistor TR, a Zener diode DZ1, a digital voltmeter and the like and converts a voltage V0 into a unified signal of 4-20mA, for instance, as output.
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