Patent US3631336A successfully refreshed from Google Patents.
US3631336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for determining deviation from resonance of lc networks by cancelling inphase component and sensing quadrature component
Assignee: AT&T Inc
•
Filing: 1969-12-22
•
Granted: 1971-12-28
•
Expires: 1989-12-22
Abstract
Abstract A circuit for measuring the deviation of resonance of a series LC circuit includes an operational amplifier with the series LC circuit connected in a feedback path. The amplifier output is connected to both an inphase discriminator and a quadrature discriminator. The output of the inphase discriminator controls an inverted inphase circuit to cancel out a substantial portion of the inphase component of the amplifier output which is applied to the quadrature discriminator. A circuit for measuring the deviation from resonance of a parallel resonance LC circuit includes a transformer with one side of the secondary connected in series with the operational amplifier and the LC circuit and with the opposite side of the transformer connected by a radiant energy controlled resistor to the input of the amplifier. The radiant energy controlled resistor is controlled by a lamp operated by an inphase discriminator to cancel a substantial portion of the inphase component of the signal through the parallel resonant circuit.
Inventors
- 👤 William H Marvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:13
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
187 words
A circuit for determining deviation from desired resonance of a series LC network comprising: a generator for producing a signal having the desired frequency of resonance; means connected to the generator for applying the signal to the network and passing a current through the network to produce an intermediate voltage having inphase and quadrature components proportional to inphase and quadrature components of the impedance of the network; a first phase-discriminating means connected to the generator and to the intermediate voltage producing means for producing a control voltage having a magnitude proportional to the magnitude of the inphase component of the intermediate voltage; means connected to the generator and responsive to the control voltage from the first phase-discriminating means for cancelling a substantial portion of the inphase component of the intermediate voltage by adding an inverted inphase voltage to the intermediate voltage, the magnitude of the inverted inphase voltage being proportional to the magnitude of the control voltage; and a second phase-discriminating means connected to the generator and to the intermediate voltage producing means for producing an output voltage proportional to the quadrature component of the intermediate voltage.
Claim 2
Dependent Claim
187 words
A circuit for determining deviation from desired resonance of a series LC network comprising: a generator for producing a signal having the desired frequency of resonance; means connected to the generator for applying the signal to the network and passing a current through the network to produce an intermediate voltage having inphase and quadrature components proportional to inphase and quadrature components of the impedance of the network; a first phase-discriminating means connected to the generator and to the intermediate voltage producing means for producing a control voltage having a magnitude proportional to the magnitude of the inphase component of the intermediate voltage; means connected to the generator and responsive to the control voltage from the first phase-discriminating means for cancelling a substantial portion of the inphase component of the intermediate voltage by adding an inverted inphase voltage to the intermediate voltage, the magnitude of the inverted inphase voltage being proportional to the magnitude of the control voltage; and a second phase-discriminating means connected to the generator and to the intermediate voltage producing means for producing an output voltage proportional to the quadrature component of the intermediate voltage.
Claim 3
Dependent Claim
24 words
A circuit as defined in claim 1, wherein: the intermediate voltage producing means includes an amplifier with the network connected in a feedback circuit.
Claim 4
Dependent Claim
38 words
A circuit as defined in claim 2, wherein the cancelling means includes: a radiant energy controlled resistance serially connected between the generator and the second phase-discriminating means; and a radiant energy emission device energized by the control voltage.
Claim 5
Dependent Claim
189 words
a circuit for determining deviation from desired resonance of a parallel LC network, comprising: a generator for producing a signal having the desired frequency of resonance; means having an input connected in series with the generator and the network for producing an intermediate voltage having inphase and quadrature components proportional to inphase and quadrature components of the current into the input thereof; a first phase-discriminating means connected to the generator and to the intermediate voltage producing means for producing a control voltage having a magnitude proportional to the magnitude of the inphase component of the intermediate voltage; means responsiVe to the control voltage from the first phase-discriminating means for cancelling a substantial portion of the inphase component of current into the input of the intermediate voltage producing means by applying an inverted inphase current to the input of the intermediate voltage producing means, the magnitude of the inverted inphase current being proportional to the magnitude of the control voltage; and a second phase-discriminating means connected to the generator and the intermediate voltage producing means for producing an output voltage proportional to the quadrature phase component of the intermediate voltage.
Claim 6
Dependent Claim
189 words
a circuit for determining deviation from desired resonance of a parallel LC network, comprising: a generator for producing a signal having the desired frequency of resonance; means having an input connected in series with the generator and the network for producing an intermediate voltage having inphase and quadrature components proportional to inphase and quadrature components of the current into the input thereof; a first phase-discriminating means connected to the generator and to the intermediate voltage producing means for producing a control voltage having a magnitude proportional to the magnitude of the inphase component of the intermediate voltage; means responsiVe to the control voltage from the first phase-discriminating means for cancelling a substantial portion of the inphase component of current into the input of the intermediate voltage producing means by applying an inverted inphase current to the input of the intermediate voltage producing means, the magnitude of the inverted inphase current being proportional to the magnitude of the control voltage; and a second phase-discriminating means connected to the generator and the intermediate voltage producing means for producing an output voltage proportional to the quadrature phase component of the intermediate voltage.
Claim 7
Dependent Claim
49 words
A circuit as defined in claim 4, wherein: the intermediate voltage producing means includes a feedback amplifier and a transformer with a primary winding connected to the generator and with the parallel LC network connected serially with a secondary winding of the transformer and the input of the amplifier.
Claim 8
Dependent Claim
49 words
A circuit as defined in claim 5, wherein the cancelling means includes: a radiant energy controlled resistance in series with an opposed secondary winding of the transformer and the input of the amplifier; and a radiant energy emission device controlled by the control voltage from the first phase-discriminating means.
References Cited (Backward Citations)
US2759146A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |