Patent US2986340A successfully refreshed from Google Patents.
US3581184A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isolator for dc signal transmitter
Assignee: Honeywell Inc
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Filing: 1969-05-19
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Granted: 1971-05-25
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Expires: 1989-05-19
Abstract
Abstract There is disclosed a signal isolator for DC signals which includes a closed-loop, magnetic induction null-balanced output circuit. The DC input signals are chopped and applied as input signals to a first or input winding on a transformer. A sensing winding of the transformer detects the net flux in the transformer core. The signal thereby produced is amplified and converted to a DC output signal. A portion of the output signal is chopped and applied as feedback signal to a third or feedback winding on the transformer. The feedback signal is synchronous with the signal applied to the input winding and is applied to the feedback winding in such a way that the flux produced thereby opposes the flux produced by the signal in the input winding. The sensing winding detects any net flux resultant from the opposed input and feedback signals.
Inventors
- 👤 Edward T E Hurd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:12
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/38; H03F3/387
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
156 words
A signal isolator for conductively isolating a DC input signal means from an output DC signal means, said isolator comprising a transformer having an input winding means, a feedback winding means and a flex difference sensing winding means; means connected to said input winding means for converting DC input signals to alternating signals whereby to produce a first alternating magnetic flux in said transformer; means connected to said flux difference sensing winding for producing an output DC signal proportional to the amplitude of the flux difference sensed by said sensing winding; means responsive to said output signal for producing a proportional alternating feedback signal; and means connected to said feedback winding means for applying said feedback signal thereto whereby to produce a second alternating magnetic flux in said transformer in opposition to said first alternating magnetic flux, said flux difference sensed by said sensing winding being the resultant of said first and second alternating magnetic flux.
Claim 2
Dependent Claim
156 words
A signal isolator for conductively isolating a DC input signal means from an output DC signal means, said isolator comprising a transformer having an input winding means, a feedback winding means and a flex difference sensing winding means; means connected to said input winding means for converting DC input signals to alternating signals whereby to produce a first alternating magnetic flux in said transformer; means connected to said flux difference sensing winding for producing an output DC signal proportional to the amplitude of the flux difference sensed by said sensing winding; means responsive to said output signal for producing a proportional alternating feedback signal; and means connected to said feedback winding means for applying said feedback signal thereto whereby to produce a second alternating magnetic flux in said transformer in opposition to said first alternating magnetic flux, said flux difference sensed by said sensing winding being the resultant of said first and second alternating magnetic flux.
Claim 3
Dependent Claim
49 words
The invention as set forth in claim 1 wherein said means connected to said flux difference winding comprises an AC amplifier, a signal demodulator and a DC amplifier, said DC amplifier being characterized in that an output current signal is produced which is proportional to an input voltage signal.
Claim 4
Dependent Claim
58 words
The invention as set forth in claim 2 wherein said means for producing an alternating feedback signal comprises a scaling resistance network connected to the output of said DC amplifier and a signal converter connected between said resistance network and said feedback winding, said signal converter being operated synchronously with said converting means connected to said input winding.
Claim 5
Dependent Claim
26 words
The invention as set forth in claim 3 wherein said signal demodulator is driven synchronously with respect to said converting means connected to said input winding.
Claim 6
Dependent Claim
17 words
The invention as set forth in claim 1 wherein said converting means comprises a solid-state signal converter.
Claim 7
Dependent Claim
33 words
The invention as set forth in claim 3 wherein said signal converting means connected to said input winding, said converter connected to said feedback winding and said demodulator are each solid-state switching means.
Claim 8
Dependent Claim
22 words
The invention as set forth in claim 6 wherein said DC amplifier comprises a pair of transistors connected as a Darlington pair.
Claim 9
Dependent Claim
337 words
An isolated signal transmitter comprising, in combination, input means for connection to a source of DC input signals; first converter means connected to said input means for providing an alternating signal proportional to said input signal; an AC amplifier connected to the output of said first converter means for amplifying said alternating signal; a first demodulator connected to the output of said AC amplifier and driven synchronously with said first converter means for producing a DC signal proportional to said amPlified AC signal; a negative feedback circuit connected between the output of said first demodulator and the input of said first converter means; a second signal converter means; a first signal scaling resistance network connected between the output of said first demodulator and said second converter means, transformer having an input winding, a feedback winding, and a flux difference sensing winding; the output of said second converter means being connected to said input winding whereby to produce a first alternating magnetic flux in said transformer; a second AC amplifier, said flux difference sensing winding being connected to the input of said AC amplifier for amplifying alternating signals developed in said sensing winding; a second demodulator having its input connected to the output of said second AC amplifier and driven synchronously with said second converter means whereby to produce a DC signal proportional to said alternating signals developed in said sensing winding; a DC amplifier connected to the output of said second demodulator for producing an output current signal proportional to said last mentioned DC signal; a third signal converter means; a second signal scaling resistance network connected between the output of said DC amplifier and the input of said third signal converter means, the output of said third converter means being connected to said feedback winding on said transformer whereby to produce a second alternating magnetic flux in said transformer in opposition to said first alternating magnetic flux, said flux difference sensed by said sensing winding being the resultant of said first and second alternating magnetic flux.
Claim 10
Dependent Claim
337 words
An isolated signal transmitter comprising, in combination, input means for connection to a source of DC input signals; first converter means connected to said input means for providing an alternating signal proportional to said input signal; an AC amplifier connected to the output of said first converter means for amplifying said alternating signal; a first demodulator connected to the output of said AC amplifier and driven synchronously with said first converter means for producing a DC signal proportional to said amPlified AC signal; a negative feedback circuit connected between the output of said first demodulator and the input of said first converter means; a second signal converter means; a first signal scaling resistance network connected between the output of said first demodulator and said second converter means, transformer having an input winding, a feedback winding, and a flux difference sensing winding; the output of said second converter means being connected to said input winding whereby to produce a first alternating magnetic flux in said transformer; a second AC amplifier, said flux difference sensing winding being connected to the input of said AC amplifier for amplifying alternating signals developed in said sensing winding; a second demodulator having its input connected to the output of said second AC amplifier and driven synchronously with said second converter means whereby to produce a DC signal proportional to said alternating signals developed in said sensing winding; a DC amplifier connected to the output of said second demodulator for producing an output current signal proportional to said last mentioned DC signal; a third signal converter means; a second signal scaling resistance network connected between the output of said DC amplifier and the input of said third signal converter means, the output of said third converter means being connected to said feedback winding on said transformer whereby to produce a second alternating magnetic flux in said transformer in opposition to said first alternating magnetic flux, said flux difference sensed by said sensing winding being the resultant of said first and second alternating magnetic flux.
References Cited (Backward Citations)
US3241080A
Cited
US3430125A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |