Patent US5157841A successfully refreshed from Google Patents.
US5157841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable electronic compass
Assignee: Individual
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Filing: 1991-02-01
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Granted: 1992-10-27
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Expires: 2011-02-01
Abstract
Abstract The invention is a motion sensitive, battery operated compass utilizing Hall effect digital switches to sense the orientation of the compass in relation to the earth's magnetic field. A vibration sensing circuit serves to turn the compass on when it is in motion, and to turn the compass off when it is at rest. A chopper circuit is provided to interrupt the power supply at a predetermined frequency to conserve battery power. The Hall effect switches are mounted in a known relationship to a rotating magnet allowing selection and decoding of the sensor outputs to provide signals for the operation of an alpha numberic display.
Inventors
- 👤 Robert C. Dinsmore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:35
CPC Classifications
G; G01; G01C; G01C17/00; G01C17/02; G01C17/28
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
98 words
A compass comprising: a. a plurality of Hall effect sensors; b. a magnet pivotably mounted in fixed proximity to said sensors; c. a signal generating circuit means for detecting the electrical current flowing through said sensors; d. display means for, converting said generated signals into a visible display corresponding to the orientation of said magnet in relation to said sensor; e. a motion-sensing switch for activating said circuit means only when said compass is in motion; f. an oscillating power supply for supplying cyclical power impulses to said circuit means, said Hall effect sensors and said display means.
Claim 2
Dependent Claim
98 words
A compass comprising: a. a plurality of Hall effect sensors; b. a magnet pivotably mounted in fixed proximity to said sensors; c. a signal generating circuit means for detecting the electrical current flowing through said sensors; d. display means for, converting said generated signals into a visible display corresponding to the orientation of said magnet in relation to said sensor; e. a motion-sensing switch for activating said circuit means only when said compass is in motion; f. an oscillating power supply for supplying cyclical power impulses to said circuit means, said Hall effect sensors and said display means.
Claim 3
Dependent Claim
63 words
The invention according to claim 1, wherein said motion sensing switch further comprises: a. a piezo-electric motion sensing device; b. means for detecting the output of said piezoelectric motion sensing device; c. means for amplifying the output of said piezoelectric motion sensing device; and d. means for connecting said amplified output of said piezo-electric motion sensing device to said signal generating circuit means.
Claim 4
Dependent Claim
32 words
The invention of claim 1, wherein said oscillating power supply further comprises: a. a programmable a stable multi-vibrator, and b. output transistor means for amplifying the output of said a stable multi-vibrator.
Claim 5
Dependent Claim
18 words
The invention of claim 3, wherein said output comprises an on-cycle to off-cycle ratio of approximately one percent.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-10-27 | 1996-04-27 | 1996-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-27 | 2000-04-27 | 2000-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-27 | 2004-04-27 | 2004-10-27 | $7700.00 | Window Closed / Lapsed |