Patent US4181879A successfully refreshed from Google Patents.
US4181879A
Expired / Lapsed
US
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Mine search coil simulator
Assignee: United States Department of the Navy
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Filing: 1978-02-13
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Granted: 1980-01-01
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Expires: 1998-02-13
Abstract
Abstract A passive inductor and associated circuitry which enables a compact searchoil to simulate the response characteristics of a service mine search coil having different electrical properties. Output from the passive inductor is amplified and modified to duplicate frequency response characteristics at ship frequency, magnetic sensitivity, and output impedance of a larger search coil. Provision is made for disengagement of magnetic surveillance by the inductor.
Inventors
- 👤 Gaylon L. West
- 👤 John M. Boyle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:47
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/08; G01V3/10; G01V3/101
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
160 words
A mine search coil simulator, comprising: a passive inductor for producing an electrical signal output in response to motion of a remote ferrous body; an electronic switch connected to said passive inductor; an operational amplifier connected to said electronic switch to receive a signal therefrom; a gain control circuit for controlling the gain of said operational amplifier connected thereto; an impedance matching circuit connected to said operational amplifier; a zero off-set for eliminating the effects of environmental electromagnetic fields connected to said gain control circuit; a pulse counter connected to said electronic switch; an astable multivibrator connected to said pulse counter for providing pulses thereto; a light-sensitive transistor having an emitter, a collector and a base, said emitter connected to said astable multivibrator; and a light-emitting diode having an anode and a cathode, said light-emitting diode configured to supply light to said base of said light-sensitive transistor in response to a control signal applied across said anode and said cathode.
Claim 2
Dependent Claim
160 words
A mine search coil simulator, comprising: a passive inductor for producing an electrical signal output in response to motion of a remote ferrous body; an electronic switch connected to said passive inductor; an operational amplifier connected to said electronic switch to receive a signal therefrom; a gain control circuit for controlling the gain of said operational amplifier connected thereto; an impedance matching circuit connected to said operational amplifier; a zero off-set for eliminating the effects of environmental electromagnetic fields connected to said gain control circuit; a pulse counter connected to said electronic switch; an astable multivibrator connected to said pulse counter for providing pulses thereto; a light-sensitive transistor having an emitter, a collector and a base, said emitter connected to said astable multivibrator; and a light-emitting diode having an anode and a cathode, said light-emitting diode configured to supply light to said base of said light-sensitive transistor in response to a control signal applied across said anode and said cathode.
Claim 3
Dependent Claim
38 words
A mine search coil simulator according to claim 1 wherein said passive inductor comprises: a metallic core; and a length of electrical conductor wound around said metallic core to define a plurality of separate coils connected in series.
Claim 4
Dependent Claim
18 words
A mine search coil simulator according to claim 1 wherein said gain control circuit includes a variable resistance.
Claim 5
Dependent Claim
17 words
A mine search coil simulator according to claim 1 wherein said impedance matching circuit comprises a resistance.
Claim 6
Dependent Claim
18 words
A mine search coil simulator according to claim 1 wherein said zero off-set circuit comprises a variable resistance.
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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) | 1982-12-31 | 1983-07-02 | 1984-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-31 | 1987-07-02 | 1988-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-31 | 1991-07-02 | 1992-01-01 | $7700.00 | Window Closed / Lapsed |