US4091340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oscillator circuit arrangements including nullator-norator pairs
Assignee: Post Office
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Filing: 1976-06-09
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Granted: 1978-05-23
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Expires: 1996-06-09
Abstract
Abstract The invention relates to electrical oscillators arranged to oscillate so as to produce a substantially sinusoidal output signal. The said oscillator includes a general impedance transvertor circuit arrangement having two differential amplifiers connected only to a plurality of resistive and capacitive impedance elements and arranged to simulate a tuned circuit with sufficient feedback to maintain oscillation within the tuned circuit. The transvertor circuit is an active device in the form of an impedance invertor circuit or a convertor circuit.
Inventors
- 👤 Alan John Greaves
- 👤 Phillip Ernest Greenaway
- 👤 John Mortimer Rollett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:24
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/20; H03B2200/00; H03B2200/006; H03B2200/0086; H03B2200/0092
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
344 words
An oscillator circuit arrangement including two nullator-norator pairs, three resistive impedance elements and three selectable tuning elements arranged alternately in a ring to form a closed chain having six nodes, consisting of a first node, a second node, a third node, a fourth node, a fifth node and a sixth node, odd numbered nodes, one, three and five, being interconnected by two nullator means, and each of nodes two and four being connected to node six by a norator means and wherein two of said selectable tuning elements are capacitors and a third selectable tuning element is a resistive impedance element, in which the two nullator-norator pairs consist of a first and a second differential input operational amplifier, each having an inverting input, a non-inverting input and an output, and in which the non-inverting input of the second amplifier is connected to the first node; and output of the first amplifier is connected to the second node; the inverting input terminal of the first amplifier is connected to the third node; the output of the second amplifier is connected to the fourth node; the non-inverting input of the first amplifier and the inverting input of the second amplifier are directly connected together and are directly connected to the fifth node; and in which the first resistive impedance element is connected between the first and second nodes; the second resistive impedance element is connected between the third and fourth nodes; and the third resistive impedance element is connected between the fifth and sixth nodes; and in which a first of said selectable tuning elements is connected between the first and the sixth nodes; a second of said selectable tuning elements is connected between the second and third nodes; and a third of said selectable tuning elements is connected between the fourth and fifth nodes; the arrangement being such that two of said tuning elements are capacitances and the third tuning element is a resistance, and wherein a passive positive impedance element is connected to provide a feed-back signal to maintain stable oscillation within the circuit.
Claim 2
Dependent Claim
344 words
An oscillator circuit arrangement including two nullator-norator pairs, three resistive impedance elements and three selectable tuning elements arranged alternately in a ring to form a closed chain having six nodes, consisting of a first node, a second node, a third node, a fourth node, a fifth node and a sixth node, odd numbered nodes, one, three and five, being interconnected by two nullator means, and each of nodes two and four being connected to node six by a norator means and wherein two of said selectable tuning elements are capacitors and a third selectable tuning element is a resistive impedance element, in which the two nullator-norator pairs consist of a first and a second differential input operational amplifier, each having an inverting input, a non-inverting input and an output, and in which the non-inverting input of the second amplifier is connected to the first node; and output of the first amplifier is connected to the second node; the inverting input terminal of the first amplifier is connected to the third node; the output of the second amplifier is connected to the fourth node; the non-inverting input of the first amplifier and the inverting input of the second amplifier are directly connected together and are directly connected to the fifth node; and in which the first resistive impedance element is connected between the first and second nodes; the second resistive impedance element is connected between the third and fourth nodes; and the third resistive impedance element is connected between the fifth and sixth nodes; and in which a first of said selectable tuning elements is connected between the first and the sixth nodes; a second of said selectable tuning elements is connected between the second and third nodes; and a third of said selectable tuning elements is connected between the fourth and fifth nodes; the arrangement being such that two of said tuning elements are capacitances and the third tuning element is a resistance, and wherein a passive positive impedance element is connected to provide a feed-back signal to maintain stable oscillation within the circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |