Current sensor

Claim 2

A sensor for measuring the magnitude of an A.C. current, comprising: first and second conductive members positioned parallel to, and spaced from, one another; said first and second conductive members each having a current flowing therethrough, with at least one of said currents being said A.C. current; and means positioned between said conductive members for generating a signal of magnitude responsive to the magnitude of a force generated by the currents flowing through said conductive members.

Claim 3

The sensor of claim 1, wherein said generating means includes a piezoresistive member.

Claim 4

The sensor of claim 1, wherein said generating means includes a piezoelectric member.

Claim 5

The sensor of claim 1, wherein said A.C. current flows through only one of said conductors and a substantially constant current flows through the other of said conductors.

Claim 6

The sensor of claim 1, wherein said A.C. current flows in the same direction through both of said conductors.

Claim 7

The sensor of claim 1, wherein opposite ends of each of said first and second conductive members are connected together to allow said current to be introduced into said sensor at a first end of the first conductor and to flow from said sensor at a second end of said second conductor.

Claim 8

The sensor of claim 6, further including means for electrically insulating said generating means from each of said conductive members.

Claim 9

The sensor of claim 6, wherein said generating means includes a piezoelectric member.

Claim 10

The sensor of claim 8, further comprising electrode means formed on said piezoelectric member for providing access to the signal generated thereby.

Claim 11

The sensor of claim 8, further comprising means for electrically insulating said piezoelectric member from each of said conductive members.

Claim 12

The sensor of claim 10, wherein said insulating means includes first and second rigid insulators, each positioned between one of said conductive members and said piezoelectric member.

Claim 13

The sensor of claim 8, wherein each of said first and second conductive members is an L-shaped member having a longer leg portion and a shorter leg portion, and said piezoelectric member is parallelly positioned between the longer leg portions.

Claim 14

The sensor of claim 12, wherein said piezoelectric member is a layer of a piezoelectric material.

Claim 15

The sensor of claim 13, wherein said piezoelectric material is selected from the group consisting of polyvinylidene fluoride and a lead zirconate titanate ceramic.

Claim 16

The sensor of claim 1, fabricated upon the surface of an insulative substrate.

Claim 17

In combination, a pair of the sensors of claim 6; first and second unidirectionally-conducting elements, each in series connection with a second conductor second end of a different sensor and oppositely-poled; the first conductor first ends of both sensors connected in parallel to form a first terminal; the terminals of said first and second unidirectionally-conducting elements furthest from said sensors being connected in parallel to form a second terminal; first and second means, each respectively receiving the signal generated by the generating means of one of the first and second sensors, each for providing a signal varying as the square root of the associated generating means signal; and means for subtracting one of the square-root-varying signals from the other, to provide an output signal of magnitude varying proportional to the magnitude of the current flowing from one to the other of said first and second terminals.