Electricity: measuring and testing – Magnetic – Displacement
Patent
1991-11-27
1992-08-18
Wieder, Kenneth A.
Electricity: measuring and testing
Magnetic
Displacement
116277, 137554, 324226, G01B 714, F16K 3700
Patent
active
051402637
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.
REFERENCES:
patent: 3107621 (1962-01-01), Tabersky
patent: 3602254 (1971-08-01), Fawkes
patent: 3859619 (1975-01-01), Ishihara et al.
patent: 3914994 (1975-10-01), Banner
patent: 4429578 (1984-02-01), Darrel et al.
patent: 4498495 (1985-02-01), Worwood et al.
patent: 4507976 (1985-04-01), Banko
patent: 4523286 (1985-06-01), Koga et al.
patent: 4535629 (1985-08-01), Prine
patent: 4573114 (1986-02-01), Ferguson et al.
patent: 4618824 (1986-10-01), Magee et al.
patent: 4636780 (1987-01-01), Thomas et al.
patent: 4711266 (1987-12-01), Leiber
patent: 4737774 (1988-04-01), Chapman et al.
patent: 4777979 (1988-10-01), Twerdochlib
patent: 4833453 (1989-05-01), Twerdochlib
patent: 4849655 (1989-07-01), Bennett
patent: 4914388 (1990-04-01), Kalista et al.
patent: 4977778 (1990-12-01), Nafziger et al.
"Significant Operating Experience Report", Institute of Nuclear Power Operations, Atlanta, Ga., Oct. 15, 1986, pp. 1-13.
Haynes et al., "Performance Monitoring of Swing Check Valves Using Magnetic Flux Signature Analysis", Oak Ridge National Laboratory, May 1989, pp. 1-10.
"Application Guidelines for Check Valves in Nuclear Power Plants", EPRI, Jan. 1988, pp. cover, 4-1 to 4-10 and 5-1 to 5-18.
Edmonds W. S.
Liberty Technology Center, Inc.
Wieder Kenneth A.
LandOfFree
System for determining position of an internal, movable conducti does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System for determining position of an internal, movable conducti, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System for determining position of an internal, movable conducti will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1251340