US3824497A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-purity, frequency-stable, adjustable, wien-bridge, oscillator
Assignee: United States Department of the Navy
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Filing: 1973-07-20
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Granted: 1974-07-16
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Expires: 1993-07-20
Abstract
Abstract A high-purity, amplitude-stable, adjustable, Wien bridge oscillator utilizing a single amplifier component and a pair of nonlinear devices. A single operational amplifier is utilized in place of two amplifier components. A lamp in the degenerativefeedback path provides amplitude stabilization of the output oscillations. A back-to-back zener diode in series with a resistor is connected between the inverting input of the operational amplifier and a junction between the series resistorcapacitor arm of the bridge circuit thereby extending the linear operating-frequency range of the oscillator, improving amplitude stability of the output oscillations, and preventing output D.C. drift from feeding back to the inverting input of the operational amplifier through the back-to-back zener diode.
Inventors
- 👤 C Schwerdt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:35
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/20; H03B5/26
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
234 words
An adjustable-frequency, resistance-capacitance-tuned oscillator comprising: an amplifier having an output, an inverting input, and a non-inverting input; means providing a reference voltage; degenerative feedback means having a resistive element, and a non-linear element including an impedance having a value that varies with the current therethrough, said elements being connected in series, said degenerative feedback means being connected between said amplifier output and said reference voltage means; a first junction between said resistive element and said nonlinear, said junction being connected to said inverting input; adjustable, frequency-determining regenerative-feedback means having a series, adjustable, resistance-caacitance network including a resistance and capacitance in series at least one of which may be variable, and a parallel, adjustable resistance-capacitance network, including a resistance and capacitance in parallel, at least one of which may be variable, said networks being connected in series between said amplifier output and said reference voltage; a second junction between said series network and said parallel network, said second junction being connected to said noninverting input; a third junction between said resistance and capacitance of said series network, said resistance of said series network being connected between said third junction and said second junction, said capacitance of said series network being connected between said third junction and said amplifier output; and a non-linear network, including an impedance having a value that varies with the current flowing therethrough connected between said third junction and said inverting input.
Claim 2
Dependent Claim
234 words
An adjustable-frequency, resistance-capacitance-tuned oscillator comprising: an amplifier having an output, an inverting input, and a non-inverting input; means providing a reference voltage; degenerative feedback means having a resistive element, and a non-linear element including an impedance having a value that varies with the current therethrough, said elements being connected in series, said degenerative feedback means being connected between said amplifier output and said reference voltage means; a first junction between said resistive element and said nonlinear, said junction being connected to said inverting input; adjustable, frequency-determining regenerative-feedback means having a series, adjustable, resistance-caacitance network including a resistance and capacitance in series at least one of which may be variable, and a parallel, adjustable resistance-capacitance network, including a resistance and capacitance in parallel, at least one of which may be variable, said networks being connected in series between said amplifier output and said reference voltage; a second junction between said series network and said parallel network, said second junction being connected to said noninverting input; a third junction between said resistance and capacitance of said series network, said resistance of said series network being connected between said third junction and said second junction, said capacitance of said series network being connected between said third junction and said amplifier output; and a non-linear network, including an impedance having a value that varies with the current flowing therethrough connected between said third junction and said inverting input.
Claim 3
Dependent Claim
21 words
The oscillator of claim 1 wherein said non-linear network comprises a resistive element and a back-to-back zener diode connected in series.
Claim 4
Dependent Claim
225 words
In a variable-frequency, Wien-bridge oscillator comprising: an amplifier having an output, an inverting input, and a non-inverting input; means providing a reference voltage; a Wien-bridge circuit including a parallel, variable, resistance-capacitance arm, a series, variable, resistance-capacitance arm, a resistance arm, and a non-linear arm, said non-linear arm including an impedance having a value that varies with the current therethrough, said series, resistance-capacitance arm having a resistance and a capacitance in series; a first junction between said parallel arm and said series arm, said first junction being connected to said non-inverting input; a second junction between said series arm and said resistance arm, said second junction being connected to said amplifier output; a third junction between said resistance arm and said non-linear arm, said third junction being connected to said inverting input; a fourth junction between said non-linear arm and said parallel arm, said fourth junction being connected to said reference voltage means; a fifth junction between said resistance and said capacitance of said series arm, said resistance of said series arm being connected between said first junction and said fifth junction, said capacitance of said series arm being connected between said fifth junction and said second junction, the improvement comprising: a non-linear network, including an impedance having a value that varies with the current flowing therethrough, connected between said fifth junction and said inverting input.
Claim 5
Dependent Claim
225 words
In a variable-frequency, Wien-bridge oscillator comprising: an amplifier having an output, an inverting input, and a non-inverting input; means providing a reference voltage; a Wien-bridge circuit including a parallel, variable, resistance-capacitance arm, a series, variable, resistance-capacitance arm, a resistance arm, and a non-linear arm, said non-linear arm including an impedance having a value that varies with the current therethrough, said series, resistance-capacitance arm having a resistance and a capacitance in series; a first junction between said parallel arm and said series arm, said first junction being connected to said non-inverting input; a second junction between said series arm and said resistance arm, said second junction being connected to said amplifier output; a third junction between said resistance arm and said non-linear arm, said third junction being connected to said inverting input; a fourth junction between said non-linear arm and said parallel arm, said fourth junction being connected to said reference voltage means; a fifth junction between said resistance and said capacitance of said series arm, said resistance of said series arm being connected between said first junction and said fifth junction, said capacitance of said series arm being connected between said fifth junction and said second junction, the improvement comprising: a non-linear network, including an impedance having a value that varies with the current flowing therethrough, connected between said fifth junction and said inverting input.
Claim 6
Dependent Claim
19 words
The oscillator of claim 3, wherein said non-linear network comprises a resistance and a back-to-back zener diode in series.
Claim 7
Dependent Claim
20 words
The improvement according to claim 3, wherein said non-linear netowrk comprises a back-to-back diode and a resistor connected in series.
Claim 8
Dependent Claim
128 words
A component for use in a Wien-bridge oscillator, said Wien-bridge oscillator having an operational amplifier with an inverting input terminal, a non-inverting input terminal, and an output terminal; means for producing a reference voltage; a Wien-bridge circuit including, a variable-impedance series resistance-capacitance arm, and an adjacent arm containing a variable-impedance parallel resistance-capacitance arm, and connections from said input terminals to one diagonal of said bridge; connections from said output terminal and a point of reference voltage to the other diagonal of said bridge, said component comprising: an impedance having a value that varies with the current flowing therethrough connected between said inverting input terminal and a point between said resistance and said capacitance of said series resistance-capacitance arm, whereby the linear frequency range of said oscillator is extended.
Claim 9
Dependent Claim
128 words
A component for use in a Wien-bridge oscillator, said Wien-bridge oscillator having an operational amplifier with an inverting input terminal, a non-inverting input terminal, and an output terminal; means for producing a reference voltage; a Wien-bridge circuit including, a variable-impedance series resistance-capacitance arm, and an adjacent arm containing a variable-impedance parallel resistance-capacitance arm, and connections from said input terminals to one diagonal of said bridge; connections from said output terminal and a point of reference voltage to the other diagonal of said bridge, said component comprising: an impedance having a value that varies with the current flowing therethrough connected between said inverting input terminal and a point between said resistance and said capacitance of said series resistance-capacitance arm, whereby the linear frequency range of said oscillator is extended.
Claim 10
Dependent Claim
21 words
The component according to claim 6, wherein said component comprises resistive means and a back-to-back zener diode connected in series therewith.
Claim 11
Dependent Claim
230 words
A variable-frequency impedance-tuned oscillator comprising: a variable-frequency selective network having a series resistance-capacitance arm, whose impedance is variable, having a resistance element and a capacitance element in series; a parallel resistance-capacitance arm, whose impedance is variable, having a resistance element and a capacitance element in parallel, said series arm and said parallel arm connected in series; a variable-impedance non-linear network having a resistance and a non-linear impedance connected in series, said non-linear impedance having a value that varies with the current flowing therethrough; a second non-linear impedance network including an impedance having a value that varies with the current flowing therethrough; an amplifier having an inverting input terminal, a non-inverting input terminal, and an output terminal; means providing a source of reference potential; a connection between one terminal of said parallel arm and said reference potential, and the other terminal being connected to said non-inverting input terminal; a connection from said output terminal to said series arm and to said variable-impedance non-linear network; a connection from one terminal of said second non-linear impedance network to said inverting input terminal and to a point between said resistance and non-linear impedance of said variable-impedance non-linear network, and the other terminal being connected to a point between said resistance and said capacitance of said series arm; and a connection from said reference voltage means to said non-linear impedance of said variable-impedance non-linear network.
Claim 12
Dependent Claim
230 words
A variable-frequency impedance-tuned oscillator comprising: a variable-frequency selective network having a series resistance-capacitance arm, whose impedance is variable, having a resistance element and a capacitance element in series; a parallel resistance-capacitance arm, whose impedance is variable, having a resistance element and a capacitance element in parallel, said series arm and said parallel arm connected in series; a variable-impedance non-linear network having a resistance and a non-linear impedance connected in series, said non-linear impedance having a value that varies with the current flowing therethrough; a second non-linear impedance network including an impedance having a value that varies with the current flowing therethrough; an amplifier having an inverting input terminal, a non-inverting input terminal, and an output terminal; means providing a source of reference potential; a connection between one terminal of said parallel arm and said reference potential, and the other terminal being connected to said non-inverting input terminal; a connection from said output terminal to said series arm and to said variable-impedance non-linear network; a connection from one terminal of said second non-linear impedance network to said inverting input terminal and to a point between said resistance and non-linear impedance of said variable-impedance non-linear network, and the other terminal being connected to a point between said resistance and said capacitance of said series arm; and a connection from said reference voltage means to said non-linear impedance of said variable-impedance non-linear network.
Claim 13
Dependent Claim
24 words
The invention in accordance with claim 8, wherein said second non-linear impedance network comprises a resistance network and a back-to-back zener diode in series.
Claim 14
Dependent Claim
25 words
The invention in accordance with claim 8, wherein said resistance of said variable-impedance non-linear network is connected between said output terminal and said inverting terminal.
Claim 15
Dependent Claim
136 words
A variable-frequency impedance-tuned oscillator comprising: a bridge circuit having four arms, one of which is a variable-impedance resistor-capacitor series combination, a second arm having a non-linear network including an impedance having a value that varies with the current flowing therethrough, a third arm having a variable-impedance resistor-capacitor parallel combination, and a fourth resistive arm; a differential amplifier having an output terminal, a non-inverting input terminal, and an inverting input terminal; connections from said input terminals across one diagonal of said bridge; connections from said output terminal and a point of reference potential to the other diagonal of said bridge; and a second non-linear impedance network including an impedance having a value that varies with the current flowinG therethrough, connected between said inverting terminal and a point between the resistor and capacitor of said resistor-capacitor series arm.
Claim 16
Dependent Claim
136 words
A variable-frequency impedance-tuned oscillator comprising: a bridge circuit having four arms, one of which is a variable-impedance resistor-capacitor series combination, a second arm having a non-linear network including an impedance having a value that varies with the current flowing therethrough, a third arm having a variable-impedance resistor-capacitor parallel combination, and a fourth resistive arm; a differential amplifier having an output terminal, a non-inverting input terminal, and an inverting input terminal; connections from said input terminals across one diagonal of said bridge; connections from said output terminal and a point of reference potential to the other diagonal of said bridge; and a second non-linear impedance network including an impedance having a value that varies with the current flowinG therethrough, connected between said inverting terminal and a point between the resistor and capacitor of said resistor-capacitor series arm.
Claim 17
Dependent Claim
23 words
An oscillator according to claim 11, wherein said second non-linear impedance network comprises a resistance network and a back-to-back zener diode in series.
Claim 18
Dependent Claim
47 words
An oscillator according to claim 11, wherein: said first arm is connected between said output terminal and said non-inverting terminal; said second arm is connected between said inverting terminal and said reference voltage; and said third arm is connected between said non-inverting terminal and said reference voltage.
References Cited (Backward Citations)
US3319184A
Cited
US3500246A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |