US3631329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isolation circuit for program signals
Assignee: Individual
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Filing: 1970-04-17
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Granted: 1971-12-28
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Expires: 1990-04-17
Abstract
Abstract Through a modulation-demodulation system having an offset control to reestablish a zero reference, relatively slowly changing single-ended (grounded) electrical direct current input signals are converted to a ''''floating'''' potential that may readily be applied to bridge and other electrical devices that require a fully floating input signal. The direct current input potential is modulated (chopped) at a frequency many times removed (higher) than the effective frequency of the input signal. The modulation is then removed by a balanced demodulator using the same chopping frequency providing a floating output signal.
Inventors
- 👤 Robert L Kimball
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:14
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/38; H03F3/387
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
187 words
An isolation circuit for converting grounded input signals having a single determined polarity with respect to ground to representative ungrounded floating output signals, comprising: a. means for attenuating the input signal to provide a determinable calibration ratio between the input signal magnitude and the output signal magnitude; b. means for providing a chopping wave having essentially a constant amplitude, and constant frequency; c. means responsive to the said attenuated input signal, cooperating with the said chopping wave, for providing a grounded modulated signal; d. an isolation transformer cooperating with the said grounded modulated signal for providing an ungrounded modulated signal; e. means responsive to the said ungrounded modulated signal, cooperating with the said chopping wave, for demodulating the ungrounded modulated signal and providing an ungrounded output signal represenTative of the grounded input signal; and f. means for controlling the ratio of the positive-to-negative energy content of the said chopping wave for compensating the normal variations in circuit components of the said foregoing means (c) and (e), and the said isolation transformer, for improving the linearity of the ungrounded output signals with respect to the said input signals.
Claim 2
Dependent Claim
187 words
An isolation circuit for converting grounded input signals having a single determined polarity with respect to ground to representative ungrounded floating output signals, comprising: a. means for attenuating the input signal to provide a determinable calibration ratio between the input signal magnitude and the output signal magnitude; b. means for providing a chopping wave having essentially a constant amplitude, and constant frequency; c. means responsive to the said attenuated input signal, cooperating with the said chopping wave, for providing a grounded modulated signal; d. an isolation transformer cooperating with the said grounded modulated signal for providing an ungrounded modulated signal; e. means responsive to the said ungrounded modulated signal, cooperating with the said chopping wave, for demodulating the ungrounded modulated signal and providing an ungrounded output signal represenTative of the grounded input signal; and f. means for controlling the ratio of the positive-to-negative energy content of the said chopping wave for compensating the normal variations in circuit components of the said foregoing means (c) and (e), and the said isolation transformer, for improving the linearity of the ungrounded output signals with respect to the said input signals.
Claim 3
Dependent Claim
213 words
An isolation circuit for converting a single-ended, changing, direct current input signal, having a maximum effective frequency alternating current component and a determined maximum magnitude, to a proportionally representative floating output signal, comprising; a. means for attenuating the input signal to provide a determinable calibration ratio between the input signal magnitude and the output signal magnitude; b. means for providing a chopping wave of determined constant peak-to-peak amplitude, and a determined constant frequency; c. means responsive to the said attenuated input signal, cooperating with the said chopping wave, for providing a grounded modulated signal; d. an isolation transformer cooperating with the said grounded modulation signal for providing an ungrounded modulated signal; e. means for providing a variable direct current offset potential; f. means responsive to the said ungrounded modulated signal, cooperating with the said chopping wave and the said direct current offset potential means for demodulating the ungrounded modulated signal and providing an ungrounded output signal proportional to the said input signal; and g. means for controlling the positive-to-negative energy content of the said chopping wave for compensating the normal variations in circuit components of the said foregoing means (c) and (f), and the said isolation transformer, for improving the linearity of the ungrounded output signal with respect to the said input signal.
Claim 4
Dependent Claim
213 words
An isolation circuit for converting a single-ended, changing, direct current input signal, having a maximum effective frequency alternating current component and a determined maximum magnitude, to a proportionally representative floating output signal, comprising; a. means for attenuating the input signal to provide a determinable calibration ratio between the input signal magnitude and the output signal magnitude; b. means for providing a chopping wave of determined constant peak-to-peak amplitude, and a determined constant frequency; c. means responsive to the said attenuated input signal, cooperating with the said chopping wave, for providing a grounded modulated signal; d. an isolation transformer cooperating with the said grounded modulation signal for providing an ungrounded modulated signal; e. means for providing a variable direct current offset potential; f. means responsive to the said ungrounded modulated signal, cooperating with the said chopping wave and the said direct current offset potential means for demodulating the ungrounded modulated signal and providing an ungrounded output signal proportional to the said input signal; and g. means for controlling the positive-to-negative energy content of the said chopping wave for compensating the normal variations in circuit components of the said foregoing means (c) and (f), and the said isolation transformer, for improving the linearity of the ungrounded output signal with respect to the said input signal.
Claim 5
Dependent Claim
28 words
The isolation circuit as claimed in claim 2 wherein the said demodulating means includes means for filtering noise peaks and the chopping frequency from the said output signal.
Claim 6
Dependent Claim
39 words
The isolation circuit as claimed in claim 3 wherein the said determined frequency of the chopping wave is at least approximately 1,000 times higher in frequency than the said maximum effective frequency alternating current component of the input signal.
Claim 7
Dependent Claim
27 words
The isolation circuit as claimed in claim 4 wherein the said determined constant peak-to-peak amplitude of the chopping wave is greater than the said attenuated input signal.
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) | 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 |