A.C. electromagnetic system for determining position of an encased movable electrically conductive element
First Claim
1. A system for detecting from outside a housing the position of an electrically conductive element movably enclosed in the housing, the system comprising:
- A.C. electromagnet means connected to an A.C. voltage source and positioned proximal to the housing for generating a magnetic field penetrating the housing and the element, the A.C. electromagnet means including a coil and a core means at least partially within the coil for intensifying and focusing magnetic lines of force generated by the A.C. electromagnet means so as to penetrate the housing and the electrically conductive element from outside the housing;
sensor means for sensing the instantaneous A.C. current flowing through the electromagnet means; and
amplitude demodulation means for amplitude demodulating the sensed A.C. current and generating a trace of sensed A.C. current amplitude, an instantaneous value of the sensed A.C. current amplitude trace being related to an instantaneous position of the element in the housing.
5 Assignments
0 Petitions
Reexamination
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, includes an A.C. electromagnet positioned in close proximity to the valve casing and the disc. The magnet is excited with an A.C. voltage to generate a magnetic field which penetrates the casing and the disc. The magnetic field is detected by a sensor. A.C. current and voltage signals from the electromagnet and a magnetic field signal from the sensor are presented to a processor portion of the system. The processor portion digitizes, amplitude and phase modulates each of the three signals and generates four traces: A.C. current amplitude, magnetic field amplitude, A.C. current phase and magnetic field phase. The latter two traces are derived with respect to an A.C. voltage phase signal. Comparable baseline signals previously gathered for the valve are stored. One to four of the traces are displayed, with or without the corresponding baseline trace, for determination of disc position.
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Citations
23 Claims
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1. A system for detecting from outside a housing the position of an electrically conductive element movably enclosed in the housing, the system comprising:
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A.C. electromagnet means connected to an A.C. voltage source and positioned proximal to the housing for generating a magnetic field penetrating the housing and the element, the A.C. electromagnet means including a coil and a core means at least partially within the coil for intensifying and focusing magnetic lines of force generated by the A.C. electromagnet means so as to penetrate the housing and the electrically conductive element from outside the housing; sensor means for sensing the instantaneous A.C. current flowing through the electromagnet means; and amplitude demodulation means for amplitude demodulating the sensed A.C. current and generating a trace of sensed A.C. current amplitude, an instantaneous value of the sensed A.C. current amplitude trace being related to an instantaneous position of the element in the housing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A system for detecting from outside a housing the position of an electrically conductive element movably enclosed in the housing, the system comprising:
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A.C. electromagnet means connected to an A.C. voltage source and positioned proximal to the housing for generating a magnetic field penetrating the housing and the element, the A.C. electromagnet means including a coil and a core means at least partially within the coil for intensifying and focusing magnetic lines of force generated by the A.C. electromagnet means so as to penetrate the housing and the electrically conductive element from outside the housing; and magnetic field sensor means located proximal to the housing for sensing the magnetic field generated by the A.C. electromagnet and varied by the movable element. - View Dependent Claims (22, 23)
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Specification