Electrical energy measuring multimeter

摘要

An electrical energy measuring multimeter for measuring electrical energy consumption is disclosed. The multimeter utilizes a first input signal that is proportional to the time derivative of a current delivered to a load. The first input signal is converted to a train of pulse signals. A second input signal that is proportional to a voltage delivered to the load is compared to a periodic reference signal. This comparison produces a gate command signal which controls a switch. The switch selectively connects the train of pulse signals to a totalizer. The sum of pulses in the totalizer is related to the time integral of the product of the current and voltage delivered to the load.