Patent US5159256A successfully refreshed from Google Patents.
US3896366A
Expired / Lapsed
US
⏱️ 0.0 years remaining
D.c. to d.c. converter with conductive isolation
Assignee: Azbil Corp
•
Filing: 1973-09-28
•
Granted: 1975-07-22
•
Expires: 1993-09-28
Abstract
Abstract A d.c. isolation amplifier includes an isolating transformer one winding of which is driven by an a.c. source. A controlled load impedance is applied across a second winding of the transformer. The impedance of the load is controlled in accordance with the magnitude of a d.c. input signal. The current in all of the windings of the transformer is thus controlled as a function of the magnitude of the input signal.
Inventors
- 👤 Seiji Onogi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:22
CPC Classifications
H; H03; H03F; H03F9/00; H03F9/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
129 words
An isolating signal transducer comprising, a transformer having at least a control winding and an exciter winding, a fixed impedance member serially connected with respect to said exciter winding, means for applying a substantially constant a.c. excitation signal through said fixed impedance member to said exciter winding, a signal controlled variable impedance means connected across said control winding whereby to control the loading of said transformer windings in accordance with an applied d.c. control signal, means for applying an input control signal to said variable impedance means to effect a control thereof, and means for deriving an output signal from said transformer corresponding to the input control signal but conductively isolated thereform, said means for applying said input control signal to said variable impedance means comprising a differential amplifier.
Claim 2
Dependent Claim
129 words
An isolating signal transducer comprising, a transformer having at least a control winding and an exciter winding, a fixed impedance member serially connected with respect to said exciter winding, means for applying a substantially constant a.c. excitation signal through said fixed impedance member to said exciter winding, a signal controlled variable impedance means connected across said control winding whereby to control the loading of said transformer windings in accordance with an applied d.c. control signal, means for applying an input control signal to said variable impedance means to effect a control thereof, and means for deriving an output signal from said transformer corresponding to the input control signal but conductively isolated thereform, said means for applying said input control signal to said variable impedance means comprising a differential amplifier.
Claim 3
Dependent Claim
49 words
An isolating signal transducer as set forth in claim 1 wherein said variable impedance means comprises a transistor having a control electrode connected to be controlled by an output signal from said differential amplifier, said transistor having a controlled conductive path connected across said control winding of said transformer.
Claim 4
Dependent Claim
18 words
An isolating signal transducer as set forth in claim 2 wherein said transistor is a field effect transistor.
Claim 5
Dependent Claim
38 words
An isolating transducer as set forth in claim 1 including means for deriving a feedback signal from said transformer corresponding to said input signal, and means for applying said feedback signal to an input of said differential amplifier.
Claim 6
Dependent Claim
34 words
An isolating transducer as set forth in claim 4 wherein said means for deriving said feedback signal comprises a separate feedback winding on said transformer, and rectifier means connected to said separate feedback winding.
Claim 7
Dependent Claim
34 words
An isolating transducer as set forth in claim 4 wherein said means for deriving said output signal comprises a separate output winding on said transformer, and rectifier means connected to said separate output winding.
Claim 8
Dependent Claim
27 words
An isolating transducer as set forth in claim 4 wherein said means for deriving said feedback signal comprises a separate rectifier means connected across said control winding.
Claim 9
Dependent Claim
30 words
An isolating transducer as set forth in claim 4 wherein said means for deriving said output signal comprises a separate rectifier means connected across said exciter winding of said transformer.
References Cited (Backward Citations)
US2552088A
Cited
US2795752A
Cited
US2885637A
Cited
US3086159A
Cited
US3065399A
Cited
US3409822A
Cited
US3581184A
Cited
US3590362A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |