US4277753A
Expired / Lapsed
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Rectifier circuits
Assignee: Brookdeal Electronics Ltd
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Filing: 1979-06-11
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Granted: 1981-07-07
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Expires: 1999-06-11
Abstract
Abstract A phase-sensitive detector has its reference signal modified in a manner to ensure that the output of the rectifier is substantially insensitive to harmonic frequencies of the reference signal. To achieve this the reference signal is used to generate a low-distortion sinusoidal control signal of the same frequency as the reference signal. The control signal controls a switching signal generator to generate a switching signal for repetitively switching the signal being rectified. The switching signal has spaces of interval T1 and marks of interval T2 given by T1=To/(1+kVp) T2=To/(1-kVp) where Vp is the mean value of the control signal during the relevant interval and To and k are constants chosen so that the output of the rectifier is substantially insensitive to harmonic frequencies of the reference signal.
Inventors
- 👤 Eric A. Faulkner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:03
CPC Classifications
H; H03; H03D; H03D1/00; H03D1/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
143 words
A phase-sensitive rectifier including: a signal input terminal to which a signal to be rectified is applied; a reference input terminal to which a reference signal is applied; and means for deriving a switching signal from the reference signal for repetitively switching the signal to be rectified to obtain phase-sensitive rectification, said means comprising a control signal generator for generating a low-distortion sinusoidal control signal of frequency equal to the frequency of the reference signal, and a switching signal generator which utilizes the said control signal for generating a switching signal having spaces of interval T1 and marks of interval T2 given by T1=T0/(1+kVp) T2=T0/(1-kVp) where Vp is the mean value of the control signal during the relevant interval and T0 and k are constants chosen so that the output of the rectifier is substantially insensitive to harmonic frequencies of the control signal.
Claim 2
Dependent Claim
143 words
A phase-sensitive rectifier including: a signal input terminal to which a signal to be rectified is applied; a reference input terminal to which a reference signal is applied; and means for deriving a switching signal from the reference signal for repetitively switching the signal to be rectified to obtain phase-sensitive rectification, said means comprising a control signal generator for generating a low-distortion sinusoidal control signal of frequency equal to the frequency of the reference signal, and a switching signal generator which utilizes the said control signal for generating a switching signal having spaces of interval T1 and marks of interval T2 given by T1=T0/(1+kVp) T2=T0/(1-kVp) where Vp is the mean value of the control signal during the relevant interval and T0 and k are constants chosen so that the output of the rectifier is substantially insensitive to harmonic frequencies of the control signal.
Claim 3
Dependent Claim
24 words
The rectifier as claimed in claim 1 in which the said control signal generator comprises a triangular waveform generator and a triangular-to-sine waveform converter.
Claim 4
Dependent Claim
18 words
The rectifier as claimed in claim 2 in which the triangular-to-sine converter comprises a piecewise linear shaping circuit.
Claim 5
Dependent Claim
62 words
The rectifier as claimed in claim 3 in which the triangular waveform generator comprises two half-triangle waveform generators each generating a similar waveform comprising a ramp of the same direction of slope and an average level of zero separated by equal periods at zero level, which waveforms are in antiphase with each other, and a differential amplifier fed with the said waveform.
Claim 6
Dependent Claim
71 words
The rectifier as claimed in claim 4 in which each half-triangle generator comprises an integrator supplied with a static offset voltage and a constant-current source also supplying said integrator and controlled by a feedback loop from the output of the generator whereby to ensure that the slope of the ramp is such that the ramp terminates at a value equal to and of opposite sign to the said static offset voltage.
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) | 1984-07-06 | 1985-01-05 | 1985-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-06 | 1989-01-05 | 1989-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-06 | 1993-01-05 | 1993-07-07 | $7700.00 | Window Closed / Lapsed |