Electrical transmission or interconnection systems – Anti-induction or coupling to other systems – Magnetic or electrostatic field control
Patent
1997-06-10
1999-09-14
Paladini, Albert W.
Electrical transmission or interconnection systems
Anti-induction or coupling to other systems
Magnetic or electrostatic field control
307104, 324307, 324313, 361143, 361146, 361144, 335209, H04B 1500
Patent
active
059527340
ABSTRACT:
A coil for bucking out undesired ambient time varying magnetic fields in the region of the gap in an MRI magnet structure is energized by a servo loop controlled by a Flux Lock Circuit having, in turn, a closed loop circuit controlled by a magnetic sensor. The sensor has a pair of windings energized in parallel by a 2 KHz oscillator, the windings being oppositely poled to induce zero voltage in a third winding to which feedback signals are supplied. Extraneous fields cause an asymmetry in the current passing through the pair of windings which asymmetry is accompanied by the generation of second harmonic components which are detected and fed back to the third winding for restoring symmetry. The signal fed back to the third winding is also used for controlling the current supplied to the field bucking coil.
REFERENCES:
patent: H471 (1988-05-01), Visser
patent: 2861242 (1958-11-01), Leavitt
patent: 3801877 (1974-04-01), Griese
patent: 3808508 (1974-04-01), Ford
patent: 3872382 (1975-03-01), Bertram et al.
patent: 4262427 (1981-04-01), Lynch et al.
patent: 4362992 (1982-12-01), Young et al.
patent: 4918824 (1990-04-01), Farrar
patent: 4932951 (1990-06-01), Liboff
patent: 4933637 (1990-06-01), Ueda
patent: 4977374 (1990-12-01), Kleiner
patent: 5130655 (1992-07-01), Conti
patent: 5329416 (1994-07-01), Ushiyama
patent: 5465012 (1995-11-01), Dunnam
patent: 5469058 (1995-11-01), Dunnam
Second International Conference on "Developments in Power-System Protector", Jun. 10-12, 1980, pp. 10-14.
"Accurate measurement of d.c. and a.c. by transformer"; M. Groenenboom and J. Lisser, C. Eng., M.I.E.E.
Magnetic Amplifiers: "The Harmonic Type Magnetic Amplifier"; G.M. Ettinger, 1953; pp. 38-45.
Fonar Corporation
Paladini Albert W.
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