Patent EP0306740A2 successfully refreshed from Google Patents.
Patent US3140481A successfully refreshed from Google Patents.
US3140481A
Expired / Lapsed
US
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Reversible analog to digital converter
Assignee: HOFFMAN AND EATON
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Filing: 1961-12-28
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Granted: 1964-07-07
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Expires: 1981-12-28
Abstract
No abstract record available.
Inventors
- 👤 Philip A Hoffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:52
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/14; H03M1/22; H03M1/50
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
320 words
A REVERSIBLE ANALOG TO DIGITAL AND DIGITAL TO ANALOG CONVERTER COMPRISING A POTENTIAL SOURCE, FIRST AND SECOND CHARGE SHARING CAPACITORS, A THIRD CAPACITOR, FOURTH AND FIFTH CHARGE SHARING CAPACITORS, A SIXTH CAPACITOR, MEANS CONNECTING ONE SAID OF SAID POTENTIAL SOURCE AND ONE SIDE OF EACH OF SAID CAPACITORS TO A REFERENCE POTENTIAL, SWITCH MEANS FOR COUPLING THE OTHER SIDE OF SAID POTENTIAL SOURCE TO THE OTHER SIDES OF SAID FIRST AND FOURTH CAPACITORS TO PRODUCE A REFERENCE CHARGE ON SAID FIRST AND FOURTH CAPACITORS, PULSE RESPONSIVE SWITCH MEANS FOR PERIODICALLY CONNECTING THE OTHER SIDES OF SAID FIRST AND FOURTH CAPACITORS TO THE OTHER SIDES OF SAID SECOND AND FIFTH CAPACITORS RESPECTIVELY WHEREBY THE REFERENCE CHARGE ON SAID FIRST CAPACITOR IS PERIODICALLY DISTRIBUTED BETWEEN ON SAID FOURTH CAPACITOR IS PERIODICALLY DISTRIBUTED BETWEEN SAID FOURTH AND FIFTH CAPACITORS, PULSE RESPONSIVE SWITCH MEANS FOR SUCCESSIVELY TRANSFERRING THE SHARED CHARGE ON SAID SECOND CAPACITOR TO SAID THIRD CAPACITOR AND ON SAID FIFTH CAPACITOR TO SAID SIXTH CAPACITOR, MEANS CONNECTING THE OTHER SIDES OF SAID THIRD AND SIXTH CAPACITORS THROUGH UNITY GAIN AMPLIFIERS TO A DIFFERENTIAL AMPLIFIER, MEANS CONNECTING THE OUTPUT OF SAID DIFFERENTIAL AMPLIFIER TO AN ARITHMETIC NODE WHEREBY THE VOLTAGE SIGNAL ACROSS SAID THIRD AND SIXTH CAPACITORS CONSTITUTES ONE INPUT TO SAID NODE, MEANS CONNECTING AN ANALOG VOLTAGE TO THE OTHER INPUT OF SAID NODE, MEANS CONNECTING THE OUTPUT OF SAID NODE TO A COMPARATOR, MEANS CONNECTING A DIGITAL INPUT SIGNAL TO SAID COMPARATOR, SWITCH MEANS FOR ALTERNATIVELY CONNECTING SAID COMPARATOR TO SAID ARITHMETIC NODE FOR ANALOG TO DIGITAL OPERATION AND TO SAID DIGITAL INPUT FOR DIGITAL TO ANALOG OPERATION, AND MEANS INCLUDING SAID COMPARATOR SENSITIVE TO THE POLARITY OF THE INPUT SIGNAL TO SAID COMPARATOR FOR DISCHARGING SAID FIFTH CAPACITOR PRIOR TO CHARGE TRANSFER WHEN SAID COMPARATOR INPUT IS ONE POLARITY AND TRANSFERRING THE CHARGE ON SAID FIFTH CAPACITOR TO SAID SIXTH CAPACITOR WHEN SAID COMPARATOR INPUT IS OF THE OTHER POLARITY.
References Cited (Backward Citations)
US2817704A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-07-07 | 1968-01-06 | 1968-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-07-07 | 1972-01-06 | 1972-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-07-07 | 1976-01-06 | 1976-07-07 | $7700.00 | Window Closed / Lapsed |