Patent US4124897A successfully refreshed from Google Patents.
US4124897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compensation system for a magnetic compass
Assignee: ELECTROCOM AUTOMATION Inc ARLINGTON TX A CORP OF TX
•
Filing: 1977-04-01
•
Granted: 1978-11-07
•
Expires: 1997-04-01
Abstract
Abstract In a vehicle locating apparatus that utilizes Hall effect generators to determine the magnetic heading of the vehicle there is provided magnetic compensation by the placing of a coil around the Hall generators. A current source generator provides power to the coil of such magnitude so as to create a magnetic field which cancels the spurious local magnetic field components. The system includes a set of manual switches for inputting a rotation angle. A variable time delay circuit incorporates this rotation angle to electronically increase or decrease the measured magnetic heading angle. This electronic rotation provides for a method to correct physical misalignment of the heading sensor in the vehicle and to compensate for local magnetic deviation.
Inventors
- 👤 Willie E. Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:21
CPC Classifications
G; G01; G01C; G01C17/00; G01C17/02; G01C17/28; G01C17/38
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
61 words
A compensation system for a magnetic compass utilizing a Hall effect generator comprising: (a) a compensation coil encircling said generator, and (b) a compensation driver for generating a current in said coil to create a magnetic field surrounding said coil having a magnitude equal to but opposite in direction of local magnetic field components other than the earth's horizontal magnetic field.
Claim 2
Dependent Claim
61 words
A compensation system for a magnetic compass utilizing a Hall effect generator comprising: (a) a compensation coil encircling said generator, and (b) a compensation driver for generating a current in said coil to create a magnetic field surrounding said coil having a magnitude equal to but opposite in direction of local magnetic field components other than the earth's horizontal magnetic field.
Claim 3
Dependent Claim
88 words
A compensator system for a magnetic compass utilizing a Hall effect generator as recited in claim 1 wherein said compensation driver includes: (a) means for generating a component of the current in said coil at a level determined by the presence of magnetized bodies and soft iron in the proximity of said compass, and (b) means for generating a component of the current in said coil varying with the vertical components of the earth's field introduced into said Hall effect generator by the tilting thereof from the horizontal.
Claim 4
Dependent Claim
38 words
A compensation system for a magnetic compass utilizing a Hall effect generator as recited in claim 1 wherein said compensation driver includes means responsive to a heading angle signal for generating a current related thereto in said coil.
Claim 5
Dependent Claim
40 words
A compensation system for a magnetic compass utilizing a Hall effect generator as recited in claim 1 wherein said compensation driver includes a pendulous resistor for generating a component of current in said coil related to the pendulous movement thereof.
Claim 6
Dependent Claim
61 words
A compensation system for a magnetic compass utilizing a Hall effect generator as recited in claim 1 wherein said compensation driver includes means responsive to a heading angle for generating a component of current in said coil related thereto and further including a pendulous resistor for generating a second component of current in said coil related to the pendulous movement thereof.
Claim 7
Dependent Claim
134 words
A compensation system for a magnetic compass utilizing a Hall effect generator wherein said Hall effect generator comprises mutually perpendicular heading and transverse elements, including: (a) a heading compensation coil encircling said heading element, (b) a transverse compensation coil encircling said transverse element, (c) a first compensation driver for generating a flow of current through said heading compensation coil to create a magnetic field surrounding said coil having a magnitude equal to but opposite in direction of local magnetic field components other than the earth's horizontal magnetic field, and (d) a second compensation driver for generating a flow of current through said transverse compensation coil to create a magnetic field surrounding said coil having a magnitude equal to but opposite in direction of local magnetic field components other than the earth's horizontal magnetic field.
Claim 8
Dependent Claim
134 words
A compensation system for a magnetic compass utilizing a Hall effect generator wherein said Hall effect generator comprises mutually perpendicular heading and transverse elements, including: (a) a heading compensation coil encircling said heading element, (b) a transverse compensation coil encircling said transverse element, (c) a first compensation driver for generating a flow of current through said heading compensation coil to create a magnetic field surrounding said coil having a magnitude equal to but opposite in direction of local magnetic field components other than the earth's horizontal magnetic field, and (d) a second compensation driver for generating a flow of current through said transverse compensation coil to create a magnetic field surrounding said coil having a magnitude equal to but opposite in direction of local magnetic field components other than the earth's horizontal magnetic field.
Claim 9
Dependent Claim
69 words
A compensation system for a magnetic compass utilizing a Hall effect generator as set forth in claim 6 wherein said first compensation driver includes means responsive to a heading angle for generating a component of current in said heading compensation coil related thereto, and wherein said second compensation driver includes means responsive to a heading angle for generating a component of current in said transverse compensation coil related thereto.
Claim 10
Dependent Claim
47 words
A compensation system for a magnetic compass utilizing a Hall effect generator as set forth in claim 7 wherein said first and second compensation drivers each includes a pendulous resistor for generating a component of current in the respective compensation coils related to a pendulous movement thereof.
References Cited (Backward Citations)
US2852859A
Cited
US3253342A
Cited
US3233332A
Cited
US3425648A
Cited
US3621584A
Cited
US3991361A
Cited
US4031630A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-11-06 | 1982-05-08 | 1982-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-06 | 1986-05-08 | 1986-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-06 | 1990-05-08 | 1990-11-07 | $7700.00 | Window Closed / Lapsed |