Three phase spin motor power meter

Claim 1

Meter for measuring the energy flows from a 3-phase quasi square excitation source to a 3-phase load with a Y connected floating neutral comprising a plurality of first amplifier means for sensing individual phase voltages; a plurality of second amplifier means for sensing individual phase currents; a plurality of multiplier means having first and second input terminals and an output terminal whereby inputs to the first and second terminals are multiplied by each other and the result fed to an output terminal; said plurality of first amplifier means having outputs connected individually to said first input terminals of the plurality of multiplier means; said plurality of second amplifier means having outputs connected individually to the second input terminal of said multiplier means; averaging means having a plurality of inputs and an output; said outputs of said plurality of multiplier means being fed to the input terminals of said averaging so that the output of the averaging means will be an average of the outputs of the plurality of multiplier means; resistors connected between the 3-phase source and the 3-phase load; said load having one phase connected to ground; said second means being two differential amplifiers connected individually across different ones of said resistors so as to measure the current flow therein; said first means being two amplifiers connected individually between one side of different ones of said resistors and ground so as to sense two phases of the voltages; said multiplier means are electronic chips; and said averaging means is a current to voltage converter connected to the chips so as to average current outputs from the chips and convert the current to voltage output for the meter.