In 1995, I was working at a large conglomerate that had once competed with Thomas Edison but whose remainders exist only in entertainment. I had to design a voltage-attenuator box for use with a new three'phase power-measurement board. I found a precision ceramic part with matched resistors. This type of part typically finds use in precision laboratory meters. To minimize heat generation, I chose a part with 10-MΩ resistance and eliminated the analog multipliers of previous designs. Instead, I digitized the raw current and voltage waveforms and performed multiplication in software using the two-wattmeter method. I thought this design clever for a guy with only mechanical-engineering degrees.
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