Patent US4942372A successfully refreshed from Google Patents.
US4942372A
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Method and circuit for reduction of temperature dependency in an oscillator
Assignee: Individual
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Filing: 1988-11-17
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Granted: 1990-07-17
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Expires: 2008-11-17
Abstract
Abstract The temperature dependency of an oscillator can be reduced by a method and circuit that uses two positive feedback paths to provide the positive feedback necessary for maintaining the oscillation of an LC-oscillating circuit. One of the two feedback paths compensates the temperature dependent influences while the other compensates temperature independent influences.
Inventors
- 👤 Peter Heimlicher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:13
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/945; H03K17/95; H03K17/952; H03K17/9537; H03K17/9542; H03K17/9547; H03L; H03L1/00; H03L1/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
116 words
A method for reducing the temperature dependency of the oscillating properties of an LC-oscillator having an oscillating circuit including a coil having temperature dependent copper losses; a condenser; and an amplifier means having input means and output means, said input means and said output means being connected to said oscillating circuit; comprising the steps of: inserting a first positive feedback path having a temperature dependent feedback characteristic between said output means and said oscillating circuit; inserting a second feedback path having a temperature independent feedback characteristic between said output means and said oscillating circuit; varying the attenuation of said oscillating circuit; and varying the feedback characteristics of said second path to compensate for said variable attenuation.
Claim 2
Independent Claim
116 words
A method for reducing the temperature dependency of the oscillating properties of an LC-oscillator having an oscillating circuit including a coil having temperature dependent copper losses; a condenser; and an amplifier means having input means and output means, said input means and said output means being connected to said oscillating circuit; comprising the steps of: inserting a first positive feedback path having a temperature dependent feedback characteristic between said output means and said oscillating circuit; inserting a second feedback path having a temperature independent feedback characteristic between said output means and said oscillating circuit; varying the attenuation of said oscillating circuit; and varying the feedback characteristics of said second path to compensate for said variable attenuation.
Claim 3
Dependent Claim
110 words
A circuit for reducing the temperature dependency of the oscillating properties of an LC-oscillator having an oscillating circuit including: a coil having temperature dependent copper losses; a condenser; amplifier means having input means and output means, said input means and said output means being connected to said oscillating circuit; positive feedback means connected between said output means and said oscillating circuit, said feedback means comprising a first feedback path having a temperature compensating feedback characteristic and a second feedback path having a temperature independent feedback characteristic; means for variably attenuating said oscillating circuit; and means for varying the feedback in said second feedback path to compensate for said variable attenuation.
Claim 4
Dependent Claim
110 words
A circuit for reducing the temperature dependency of the oscillating properties of an LC-oscillator having an oscillating circuit including: a coil having temperature dependent copper losses; a condenser; amplifier means having input means and output means, said input means and said output means being connected to said oscillating circuit; positive feedback means connected between said output means and said oscillating circuit, said feedback means comprising a first feedback path having a temperature compensating feedback characteristic and a second feedback path having a temperature independent feedback characteristic; means for variably attenuating said oscillating circuit; and means for varying the feedback in said second feedback path to compensate for said variable attenuation.
Claim 5
Dependent Claim
37 words
The circuit according to claim 2, wherein said first feedback path is formed by a first capacitor and said second feedback path is formed by a capacitive voltage divider comprising said first capacitor and a second capacitor.
Claim 6
Dependent Claim
23 words
The circuit according to claim 2, wherein said variable attenuation has resistance Rm and positive feedback is modified through said second feedback path.
Claim 7
Dependent Claim
18 words
The circuit according to claim 2, wherein said positive feedback means comprises a combined ohmic and capacitive feedback.
Claim 8
Dependent Claim
15 words
The circuit according to claim 2, wherein said second path comprises a capacitive voltage divider.
Claim 9
Dependent Claim
38 words
The circuit according to claim 2, wherein said temperature independent feedback path comprises a second amplifier means coupled to said oscillating circuit and a resistor connected between an output of the second amplifier means and said input means.
Claim 10
Dependent Claim
17 words
The circuit according to claim 2, wherein said first and second feedback paths each include separate amplifiers.
Claim 11
Dependent Claim
94 words
A proximity switch having a measuring circuit including an oscillating circuit with a coil having temperature dependent copper losses and a condenser, and a driving blade displaceable within the electromagnetic field of said coil for variably attenuating said oscillating circuit, amplifier means connected to said oscillating circuit through feedbacks means for sustaining oscillation therein, said feedback means comprising a first feedback path having a temperature compensating feedback characteristic and a second feedback path having a temperature independent feedback characteristic, said second feedback path having a variable feedback characteristic for compensating for said variable attenuation.
Claim 12
Dependent Claim
94 words
A proximity switch having a measuring circuit including an oscillating circuit with a coil having temperature dependent copper losses and a condenser, and a driving blade displaceable within the electromagnetic field of said coil for variably attenuating said oscillating circuit, amplifier means connected to said oscillating circuit through feedbacks means for sustaining oscillation therein, said feedback means comprising a first feedback path having a temperature compensating feedback characteristic and a second feedback path having a temperature independent feedback characteristic, said second feedback path having a variable feedback characteristic for compensating for said variable attenuation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |