Patent USH471H successfully refreshed from Google Patents.
USH471H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Remnant field detector
Assignee: United States Department of Energy
•
Filing: 1986-11-24
•
Granted: 1988-05-03
•
Expires: 2006-11-24
Abstract
Abstract A method apparatus for qualitatively detecting remnant magnetic fields in matched pairs of magnet cores. Equal magnitude and oppositely oriented magnetic flux is induced in the magnet cores by oppositely wound primary windings and current source. Identically wound secondary windings generate output voltages in response to the induced flux. The output voltages generated should be of equal magnitude and opposite polarity if there is no remnant field in the cores. The output voltages will be unequal which is detected if either core has a remnant field.
Inventors
- 👤 Age T. Visser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:09
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
242 words
A magnetic field detector for detecting remnant magnetic fields in magnet cores associated with an apparatus having multiple magnet cores to be degaussed, said remnant field detector comprised of: first and second matched magnet cores; flux generator means coupled to said first and second magnet cores capable of inducing a predetermined magnetic flux in said first magnet core with a predetermined orientation and inducing a predetermined magentic flux in said second magnet core with an orientation opposite said orientation of said first flux in said first magnet core; first flux sensor means coupled to said first magnet core, capable of generating an output voltage from magnetic flux change in said first magnet core; second flux sensor means coupled to said second magnet core for generating an output voltage from magnetic flux change in said second magnet core; voltage comparison means coupled to said first flux sensor means and coupled to said second flux sensor means, capable of producing an output signal indicating a difference in output voltage from said first flux sensor means and from said second flux sensor means; whereby magnetic flux change generated in said magnet cores by said flux generator means causes an induced voltage in said first and second flux sensor means the magnitude and polarity of such voltages in said first and second sensor means being dependent upon remnant magnetic fields in said magnetic cores prior to induced flux in said cores from said flux generator means.
Claim 2
Dependent Claim
242 words
A magnetic field detector for detecting remnant magnetic fields in magnet cores associated with an apparatus having multiple magnet cores to be degaussed, said remnant field detector comprised of: first and second matched magnet cores; flux generator means coupled to said first and second magnet cores capable of inducing a predetermined magnetic flux in said first magnet core with a predetermined orientation and inducing a predetermined magentic flux in said second magnet core with an orientation opposite said orientation of said first flux in said first magnet core; first flux sensor means coupled to said first magnet core, capable of generating an output voltage from magnetic flux change in said first magnet core; second flux sensor means coupled to said second magnet core for generating an output voltage from magnetic flux change in said second magnet core; voltage comparison means coupled to said first flux sensor means and coupled to said second flux sensor means, capable of producing an output signal indicating a difference in output voltage from said first flux sensor means and from said second flux sensor means; whereby magnetic flux change generated in said magnet cores by said flux generator means causes an induced voltage in said first and second flux sensor means the magnitude and polarity of such voltages in said first and second sensor means being dependent upon remnant magnetic fields in said magnetic cores prior to induced flux in said cores from said flux generator means.
Claim 3
Dependent Claim
32 words
The apparatus of claim 1 where said flux generator means includes first and second coil windings wound on said first and second magnet cores with opposite orientation and a current source .
Claim 4
Dependent Claim
21 words
The apparatus of claim 2 where said the first sensor means includes a secondary winding wound on said first magnet core.
Claim 5
Dependent Claim
20 words
The apparatus of claim 3 where said second sensor means includes a secondary winding wound on said second magnet core.
Claim 6
Dependent Claim
30 words
The apparatus of claim 4 where said voltage comparison means is a bridge rectifier and operational an amplifier coupled to said secondary windings on said first and second magnet cores.
Claim 7
Dependent Claim
27 words
The apparatus of claim 4 where said voltage comparison means is a voltage comparator connected to said secondary windings on said first and said second magnet cores.
Claim 8
Independent Claim
160 words
A method for detecting remnant magnetic fields in matched pairs of first and second magnet cores said method comprised of: a predetermined magnetic flux in a first magnet core of one of said matched pairs with a predetermined orientation; inducing a predetermined magnetic flux in a second magnet core of said one matched pair with an orientation opposite said orientation of said flux in said first magnet core; measuring a voltage induced in a secondary winding on said first magnet core in response to said induced magnetic flux; measuring an induced voltage in a secondary winding on said second magnet core in response to said induced magnetic flux in said second magnet core; comparing the output voltages from the secondary windings on said first and second magnet cores and producing a measurable output voltage or signal the status of which indicates that a remnant magnetic field was present in the magnet cores prior to the application of said magnetic flux.
Claim 9
Independent Claim
160 words
A method for detecting remnant magnetic fields in matched pairs of first and second magnet cores said method comprised of: a predetermined magnetic flux in a first magnet core of one of said matched pairs with a predetermined orientation; inducing a predetermined magnetic flux in a second magnet core of said one matched pair with an orientation opposite said orientation of said flux in said first magnet core; measuring a voltage induced in a secondary winding on said first magnet core in response to said induced magnetic flux; measuring an induced voltage in a secondary winding on said second magnet core in response to said induced magnetic flux in said second magnet core; comparing the output voltages from the secondary windings on said first and second magnet cores and producing a measurable output voltage or signal the status of which indicates that a remnant magnetic field was present in the magnet cores prior to the application of said magnetic flux.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-03 | 1991-11-02 | 1992-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-03 | 1995-11-02 | 1996-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-03 | 1999-11-02 | 2000-05-03 | $7700.00 | Window Closed / Lapsed |