ELECTRONIC ACTIVE ENERGY METER Russian patent published in 1997 - IPC

FIELD: electrical measurement technology; measurement of ac active energy consumption. SUBSTANCE: meter has two integrating voltage-to-frequency converters, a standard frequency generator, an equivalence unit, and a reversible counter. Feedback pulse width in the first converter is determined by the generator period and in the second converter by the period of first converter output pulses. First and second converter inputs are connected to the outputs of a voltage transducer and a current transducer, respectively. Integrating circuit in each of the converters has a voltage difference-to-current converter and an integrating capacitor connected to its output. Transistor gates controlled by comparators maintain constant sign of voltage at first and second converter outputs. Comparator outputs are also connected to inputs of the equivalence unit. Output of the unit is connected to the up-down input of the counter. Highest order digit output of the counter serves a frequency output of the meter. EFFECT: improved design. 3 dwg