Patent US2641931A successfully refreshed from Google Patents.
US3696383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information transmission system for metered magnitudes
Assignee: Fujitsu Ltd
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Filing: 1970-12-31
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Granted: 1972-10-03
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Expires: 1990-12-31
Abstract
Abstract ON and OFF information signals are transmitted through an AC voltage distribution line via a single frequency carrier signal during a period of time in each cycle of the AC voltage when the information signal is in the ON condition and during another period of time in each such cycle when the information signal is in the OFF condition. A receiver receives the carrier signal from the distribution line synchronously with the AC voltage and determines the ON and OFF condition of the derived and received signal.
Inventors
- 👤 Hiroshi Oishi
- 👤 Fumio Aoki
- 👤 Shigeru Kawano
- 👤 Hitoshi Muramatsu
- 👤 Masahiro Saeki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:18
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/54; H04B3/542; H02; H02J; H02J13/00; H02J13/13; H02J13/1311; H02J13/1313; H04B2203/00; H04B2203/54; H04B2203/5429; H04B2203/5433; H04B2203/5462; H04B2203/5483; H04B2203/5495; Y; Y02; Y02E; Y02E60/00; Y04; Y04S; Y04S40/00; Y04S40/12; Y04S40/121
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
137 words
A data transmission system for transmitting via two distribution lines a constant cycle signal varying in accordance with the data signal ''''1'''' and ''''0,'''' superimposed on a half cycle AC voltage, said data transmission system comprising oscillator means generating a constant cycle signal; first switching means having end terminals for transmitting the constant cycle signal from the oscillator to the distribution lines; transformer means having a primary winding having two ends, an intermediate tap connected to one of the distribution lines and a secondary winding having ends connected to the end terminals of the first switching means; and second switching means having a switch arm which selectively connects one of the two ends of the primary winding of the transformer means to the other of the distribution lines in accordance with the data signal ''''1'''' and ''''0.''''
Claim 2
Dependent Claim
137 words
A data transmission system for transmitting via two distribution lines a constant cycle signal varying in accordance with the data signal ''''1'''' and ''''0,'''' superimposed on a half cycle AC voltage, said data transmission system comprising oscillator means generating a constant cycle signal; first switching means having end terminals for transmitting the constant cycle signal from the oscillator to the distribution lines; transformer means having a primary winding having two ends, an intermediate tap connected to one of the distribution lines and a secondary winding having ends connected to the end terminals of the first switching means; and second switching means having a switch arm which selectively connects one of the two ends of the primary winding of the transformer means to the other of the distribution lines in accordance with the data signal ''''1'''' and ''''0.''''
Claim 3
Dependent Claim
86 words
A data transmission system as claimed in claim 1, further comprising a bandpass filter coupled to the distribution lines and passing only the constant cycle signal of the oscillator superimposed on the half cycle AC voltage transmitted via the distribution lines, detector means connected to the bandpass filter for demodulating the constant cycle signal, and differentiation circuit means coupled to the distribution lines for generating sampling pulses for sampling the demodulated constant cycle signal superimposed on the half cycle AC voltage transmitted via the distribution lines.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |