Capacitive position transducer

Claim 2

A capacitive position transducer system comprising: a first, second and third spaced apart electrodes, said first electrode of limiter area being positioned in a common surface, for relative movement in a predetermined direction with respect to said second and third electrodes and effectively spanning said second and third electrodes, said second and third electrodes each having a predetermined area, being positioned in a second surface substantially parallel to said first surface, exciter means connected to said first electrode for impressing a signal across said first electrods, said second and third electrodes each independently detecting a portion of said signal; and circuit means coupled to said second and third electrodes and responsive to said detected portions of signals for presenting a first, reference output signal whose magnitude is unchanged in response to said relative movement and a second, variable output signal whose magnitude changes in response to said relative movement.

Claim 3

A capacitive position transducer system according to claim 1 in which said second electrod presents a constant area to said first electrode, independent of said relative movement and said third electrode presents an area to said first electrode which varies with said relative movement therebetween for providing a signal to said circuit means whose magnitude is independent of said relative movement.

Claim 4

A capacitive position transducer system according to claim 1 in which the area presented to said first electrode by said second electrode varies with said relative movement according to a given function determined by the shape of said second electrode, for providing an output signal to said circuit means that varies with said relative movement according to said function.

Claim 5

A capacitive position transducer system according to claim 1, wherein said second electrode has a uniformly varying shape and said third electrode includes a first portion and a second portion each adjacent an opposite side of said second electrode, said second and third electrodes combining to present at all times, a constant area to said first electrode, independent of said relative movement.

Claim 6

A capacitive position transducer system according to claim 4 wherein said circuit means are additively coupled to said second and third electrodes to provide said first, reference output signal.

Claim 7

A capacitive position transducer system according to claim 5 wherein said circuit means are subtractively coupled to said second and third electrodes to provide said second variable output signal.

Claim 8

A capacitor position transducer system according to claim 5 wherein said circuit means are coupled to at least one of said second and third electrodes to provide said second variable output signal.

Claim 9

The capacitive transducer system according to claim 2, wherein said circuit means include a first signal channel coupled to said second electrode to provide said first, reference output signal and a second signal channel coupled to said third electrode to provide said second, variable output signal.

Claim 10

The capacitive transducer system of claim 1, further including a first guard shield surrounding said first electrode in the surface thereof, and a second guard shield surrounding said second and third electrodes in the surface thereof, said guard shields being adapted to be connected to a source of common Potential for isolating the electrodes surrounded thereby.

Claim 11

The capacitive position transducer system of claim 1, wherein said second surface is a curve, and the relative motion between said first electrode and said second and third electrodes is rotational.

Claim 12

The capacitive position transducer system of claim 1, wherein said second surface is a plane and the relative motion between said first electrode and said second and third electrodes is translational.

Claim 13

In a capacitive position transducer system, the combination comprising: first and second receptor electrodes fixedly located in a common plane and having adjacent spaced-apart edges defining an electrical discontinuity therebetween; an exciter electrode fixedly located adjacent said first and second receptor electrodes in spaced relation from the common plan thereof and spanning the electrical discontinuity therebetween, and relatively movable with respect thereto; means for connecting said exciter electrode to a source of potential to induce a signal in said receptor electrodes, indicative of the portions of said first and second electrodes spanned by said exciter electrode; and circuit means connected to said first and second receptor electrodes for supplying a first output signal whose polarity and magnitude are independent of relative position of said exciter and receptor electrodes and a second output signal whose polarity and magnitude correspond to and are representative of the relative position of said exciter and receptor electrodes.

Claim 14

In a capacitive position transducer system, the combination comprising: first and second receptor electrodes fixedly located in a common plane and having adjacent spaced-apart edges defining an electrical discontinuity therebetween; an exciter electrode fixedly located adjacent said first and second receptor electrodes in spaced relation from the common plan thereof and spanning the electrical discontinuity therebetween, and relatively movable with respect thereto; means for connecting said exciter electrode to a source of potential to induce a signal in said receptor electrodes, indicative of the portions of said first and second electrodes spanned by said exciter electrode; and circuit means connected to said first and second receptor electrodes for supplying a first output signal whose polarity and magnitude are independent of relative position of said exciter and receptor electrodes and a second output signal whose polarity and magnitude correspond to and are representative of the relative position of said exciter and receptor electrodes.

Claim 15

A capacitive position transducer system according to claim 12 in which said first receptor electrode presents a constant area to said exciter electrode, independent of relative movement therebetween and said second receptor electrode presents an area to said exciter electrode which varies with relative movement therebetween said first receptor electrode providing an output signal to said circuit means whose polarity and magnitude are independent of said relative motion.

Claim 16

A capacitive position transducer system according to claim 12 in which the area presented to said exciter electrode by said second receptor electrode varies with said relative movement according to a given function determined by the shape of said second receptor electrode, said second receptor electrode providing an output signal to said circuit means that varies with said relative movement according to said function.

Claim 17

A capacitive position transducer system according to claim 12, wherein said first receptor electrode has a uniformly varying sahpe and said second receptor electrode includes a first portion and a second portion each adjacent an opposite edge of said first receptor electrode, said first and second receptor electrodes combining to present, at all times, a constant area to said exciter electrode, independent of said relative movement.