Method for determining position of an internal, movable conductive element
First Claim
1. A method for detecting the position of an element movably enclosed in a housing, comprising the steps of:
- transmitting energy from a first transmitter located outside the housing through the housing to the element within the housing such that the transmitted energy is perturbed by impingement upon the element, the perturbation of the energy varying with varying position of the element within the housing;
detecting energy transmitted by the first energy transmitter with a detector, the first transmitter energy detected by the detector including an unperturbed component and a superimposed, perturbed component from the element;
transmitting energy detectable by the detector from a second transmitter separate from the first transmitter; and
adjusting the energy being transmitted by at least one of the first and second transmitters to at least partially cancel the unperturbed component of the first transmitter energy being detected by the detector with the second transmitter energy being detected by the detector.
2 Assignments
0 Petitions
Accused Products
Abstract
A system to determine the position of an electrically conductive element movably positioned in a housing, like a metal disc in a check valve, with greater accuracy and resolution than single magnet systems includes first and second A.C. electromagnets positioned in close proximity to the element on opposing sides of the housing. The magnets are excited with A.C. currents to generate magnetic fields which penetrate the housing and the element. The magnetic fields are sensed by a magnetic field sensor. A control portion of the system includes a microprocessor configured to allow an operator to adjustably select and set a common frequency, individual amplitudes and a phase difference between the two currents supplied to the two magnets so that the currents might be adjusted to cause the magnets to generate magnetic fields at least partially and preferably essentially cancelling one another at the sensor. The sensor senses essentially only a net perturbation in a magnetic field caused by movement of the electrically conductive member.
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Citations
32 Claims
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1. A method for detecting the position of an element movably enclosed in a housing, comprising the steps of:
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transmitting energy from a first transmitter located outside the housing through the housing to the element within the housing such that the transmitted energy is perturbed by impingement upon the element, the perturbation of the energy varying with varying position of the element within the housing; detecting energy transmitted by the first energy transmitter with a detector, the first transmitter energy detected by the detector including an unperturbed component and a superimposed, perturbed component from the element; transmitting energy detectable by the detector from a second transmitter separate from the first transmitter; and adjusting the energy being transmitted by at least one of the first and second transmitters to at least partially cancel the unperturbed component of the first transmitter energy being detected by the detector with the second transmitter energy being detected by the detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for detecting the position of an element movably enclosed in a housing comprising the steps of:
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transmitting energy from a first location outside the housing through the housing to the element within the housing, the transmitted energy being perturbed by impingement upon the element and the perturbation of the energy varying with position of the element within the housing; detecting energy from the first location including an unperturbed component and a superimposed component perturbed by the element; generating a signal from the energy detecting step, the signal having an unperturbed component corresponding to the unperturbed component of the energy being detected from the first location and a perturbed component corresponding to the component of energy being detected which is perturbed by the element; and at least partially cancelling the unperturbed component of the signal corresponding to the unperturbed portion of the energy being detected from the first location. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A method of detecting from outside a housing the position of an electrically conductive element movably enclosed in the housing comprising the steps of:
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generating an A.C. magnetic field outside the housing proximal to the housing and penetrating both the housing and the element from outside the housing; and simultaneously sensing outside the housing the A.C. magnetic field as perturbed by the electrically conductive element within the housing; and analyzing an instantaneous value of the sensed magnetic field to unambiguously differentiate from among at least three different instantaneous positions of the element. - View Dependent Claims (27, 28, 29, 30, 31, 32)
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Specification