Automatic compensation circuit for use with analog multiplier
First Claim
1. An automatic compensation circuit comprisingan analog multiplier connected to receive a first signal representing instantaneous voltage and a second signal representing instantaneous current for generating a third current signal representing the product of said first and second signals,means for converting said third current signal to a fourth voltage signal, andcompensation means connected to said converting means for adjusting the output of said converting means to zero during zero crossing points of at least one of said first or second signals.
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Abstract
An automatic compensation circuit for use with an analog multiplier is disclosed. At regular intervals at least one input to the analog multiplier is constrained to be zero for a short time. During this time a sample and hold circuit retains the pre-existing output voltage and a feedback circuit is activated which adjusts the output voltage of the multiplier to zero, thereby providing an accurate multiplied or product signal, typically representing power consumption, which is adjusted or compensated for the effects of any internal errors occurring within the analog multiplier.
32 Citations
4 Claims
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1. An automatic compensation circuit comprising
an analog multiplier connected to receive a first signal representing instantaneous voltage and a second signal representing instantaneous current for generating a third current signal representing the product of said first and second signals, means for converting said third current signal to a fourth voltage signal, and compensation means connected to said converting means for adjusting the output of said converting means to zero during zero crossing points of at least one of said first or second signals.
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2. In an electronic watt-hour meter, an automatic compensation circuit comprising
an analog multiplier connected to receive a first signal representing instantaneous voltage and a second signal representing instantaneous current for generating a third current signal representing the product of said first and seconds signals, means for converting said third signal to a fourth voltage signal, compensation means connected to said converting means for adjusting the output of said converting means to zero during zero crossing points of at least one of said first or second signals, and sample and hold means for storing the fourth voltage signal during the respective interval.
Specification