Electrical measuring systems using a quarter-square multiplier

Claim 2

A quarter-square multiplier for producing the product of a multiplier and a multiplicand, and comprising in combination: means for producing a first sequence of substantially rectangular waves each of substantially fixed frequency and fixed amplitude and having a pulse width which varies in accordance with the mean squared value of the sum of said multiplier and multiplicand; means for producing a second sequence of substantially rectangular waves each of substantially fixed frequency and fixed amplitude and having a pulse width which varies in accordance with the mean squared value of the difference between said multiplier and multiplicand; and means for producing a third signal proportional to the difference between the magnitude of the pulse widths of at least one wave of each of said first and second sequences whereby said third signal is proportional to said product.

Claim 3

A quarter-square multiplier for producing the product of a multiplier and a multiplicand, and comprising in combinAtion: means for producing a first signal having a temporal parameter which varies in accordance with the mean squared value of the sum of said multiplier and multiplicand; means for producing a second signal having a temporal parameter which varies in accordance with the means squared value of the difference between said multiplier and multiplicand; and means for producing a third signal proportional to the difference between the values of the temporal parameters of said first and second signals: wherein said means for producing said first and second signals each comprises means for producing an iterative signal in which substantially all parameters are fixed except for one temporal parameter, and means for comparing the mean squared value of said iterative signal with the mean squared value of one of said sum of or said difference between said multiplier and multiplicand so as to derive an error signal; said means for producing said iterative signal being responsive to said error signal so that as the latter tends toward zero the temporal parameter of said iterative signal varies such that the mean squared values of said iterative signal and siad one of said sum of or said difference between said multiplier and multiplicand tend toward a preselected ratio, said temporal parameters of each of said first and second signals being proportional to the temporal parameter of the respective iterative signal.

Claim 4

A quarter-square multiplier for producing the product of a multiplier and a multiplicand, and comprising in combinAtion: means for producing a first signal having a temporal parameter which varies in accordance with the mean squared value of the sum of said multiplier and multiplicand; means for producing a second signal having a temporal parameter which varies in accordance with the means squared value of the difference between said multiplier and multiplicand; and means for producing a third signal proportional to the difference between the values of the temporal parameters of said first and second signals: wherein said means for producing said first and second signals each comprises means for producing an iterative signal in which substantially all parameters are fixed except for one temporal parameter, and means for comparing the mean squared value of said iterative signal with the mean squared value of one of said sum of or said difference between said multiplier and multiplicand so as to derive an error signal; said means for producing said iterative signal being responsive to said error signal so that as the latter tends toward zero the temporal parameter of said iterative signal varies such that the mean squared values of said iterative signal and siad one of said sum of or said difference between said multiplier and multiplicand tend toward a preselected ratio, said temporal parameters of each of said first and second signals being proportional to the temporal parameter of the respective iterative signal.

Claim 5

A multiplier as defined in claim 2 wherein said means for producing said iterative signal comprises means for producing a train, at fixed repetition rate of substantially flat-topped waves of substantially fixed equal amplitude, said temporal parameter being the duration of said each wave.

Claim 6

A multiplier as defined in claim 2 wherein said means for producing said iterative signal comprises means for producing a train of waves wherein said temporal parameter is the frequency of said train.

Claim 7

A multiplier as defined in claim 3 wherein said means for producing a third signal comprises gate means for producing an output signal having a duration established by the coincidence between the duration of corresponding waves of said first and second signals.

Claim 8

A multiplier as defined in claim 3 wherein said means for comparing comprises a first terminal at which, respectively, one of said sum or said difference is intended to be applied and a second terminal at which said iterative signal is intended to be applied, means for converting the average power in a signal into an output signal, and means for alternately switching the input of the latter means between said first and second terminals.

Claim 9

A multiplier as defined in claim 6 wherein said means for converting comprises a thermocouple with an electrically actuated heater connectable through said switching means to either of said first and second terminals, whereby the output of said thermocouple is said error signal.

Claim 10

A multiplier as defined in claim 3 wherein said means for comparing comprises a first terminal at which, respectively, one of said sum or said difference is intended to be applied and a second terminalk at which said iterative signal is intended to be applied, first and second thermocouples each having an electrically actuated heater connected, respectively, to said first and second terminals, and means connecting said thermocouples to provide said error signal as the output thereof.

Claim 11

A quarter-square multiplier for producing the product of a multiplier and a multiplicand, and comprising in combination: means for producing a first signal having a temporal parameter which varies in accordance with the mean squared value of the sum of said multiplier and multiplicand; means for producing a second signal having a temporal parameter which varies in accordance with the mean squared value of the difference between said multiplier and multiplicand; means for producing a third signal proportional to the difference between the values of the temporal parameters of said first and second signals whereby said third signal is proportional to said product; means for generating a fourth signal proportional to the voltage across a power-consuming circuit, second terminal means for generating a fifth signal proportional to the product of the current flowing in said circuit times the power factor relation between said voltage and current, and means for obtaining the sum and differences of said fourth and fifth signals, said sum and differences being said multiplier and multiplicand.

Claim 12

A quarter-square multiplier for producing the product of a multiplier and a multiplicand, and comprising in combination: means for producing a first signal having a temporal parameter which varies in accordance with the mean squared value of the sum of said multiplier and multiplicand; means for producing a second signal having a temporal parameter which varies in accordance with the mean squared value of the difference between said multiplier and multiplicand; means for producing a third signal proportional to the difference between the values of the temporal parameters of said first and second signals whereby said third signal is proportional to said product; means for generating a fourth signal proportional to the voltage across a power-consuming circuit, second terminal means for generating a fifth signal proportional to the product of the current flowing in said circuit times the power factor relation between said voltage and current, and means for obtaining the sum and differences of said fourth and fifth signals, said sum and differences being said multiplier and multiplicand.

Claim 13

A multiplier as defined in claim 9 wherein said means for obtaining said sum and difference comprisies a first summing operational amplifier connected for summing said fourth and fifth signals, and a second operational amplifier having input scaling and being connected for summing the output of said first amplifier with a signal of double the value of one of said fourth or fifth signals.