Patent US2484342A successfully refreshed from Google Patents.
US3105877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for canceling oscillating in public address systems
Assignee: TDK Micronas GmbH
•
Filing: 1960-09-12
•
Granted: 1963-10-01
•
Expires: 1980-09-12
Abstract
No abstract record available.
Inventors
- 👤 Thomas P Miller
- 👤 Solly L Fudaley
- 👤 Raymond N Reinertson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:42
CPC Classifications
H; H04; H04R; H04R3/00; H04R3/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
155 words
A PUBLIC ADDRESS SYSTEM HAVING A RESONANT FREQUENCY BAND WIDTH, MEANS FOR TRANSMITTING VOICE FREQUENCY SIGNALS THROUGH SAID SYSTEM, SAID SIGNALS INCLUDING FREQUENCY FALLING IN SAID RESONANT BAND WIDTH, MEANS IN SAID SYSTEM FOR CANCELING THAT PORTION OF THE SIGNALS WHICH INCLUDES FREQUENCIES FALLING IN SAID BAND WIDTH, SAID CANCELING MEANS INCLUDING A PAIR OF SEMICONDUCTOR DEVICES, ONE OF SAID DEVICES HAVING AN INPUT ELECTRODE COUPLED TO BE ENERGIZED BY SAID VOICE SIGNALS AND AN OUTPUT ELECTRODE COUPLED TO AN INPUT ELECTRODE OF THE OTHER OF SAID DEVICES, AN OUTPUT ELECTRODE OF SAID OTHER DEVICE BEING CONNECTED TO CONTROL THE BIAS ON A THIRD ELECTRODE OF SAID ONE DEVICE, MEANS FOR APPLYING AT LEAST A PORTION OF SAID VOICE SIGNALS PHASE SHIFTED TO A THIRD ELECTRODE OF SAID OTHER DEVICE, AND MEANS ALSO COUPLED TO THE OUTPUT ELECTRODE OF SAID ONE DEVICE FOR BROADCASTING SOUNDS CORRESPONDING TO SAID VOICE FREQUENCIES LESS SAID CANCELED BAND WIDTH.
Claim 2
Dependent Claim
155 words
A PUBLIC ADDRESS SYSTEM HAVING A RESONANT FREQUENCY BAND WIDTH, MEANS FOR TRANSMITTING VOICE FREQUENCY SIGNALS THROUGH SAID SYSTEM, SAID SIGNALS INCLUDING FREQUENCY FALLING IN SAID RESONANT BAND WIDTH, MEANS IN SAID SYSTEM FOR CANCELING THAT PORTION OF THE SIGNALS WHICH INCLUDES FREQUENCIES FALLING IN SAID BAND WIDTH, SAID CANCELING MEANS INCLUDING A PAIR OF SEMICONDUCTOR DEVICES, ONE OF SAID DEVICES HAVING AN INPUT ELECTRODE COUPLED TO BE ENERGIZED BY SAID VOICE SIGNALS AND AN OUTPUT ELECTRODE COUPLED TO AN INPUT ELECTRODE OF THE OTHER OF SAID DEVICES, AN OUTPUT ELECTRODE OF SAID OTHER DEVICE BEING CONNECTED TO CONTROL THE BIAS ON A THIRD ELECTRODE OF SAID ONE DEVICE, MEANS FOR APPLYING AT LEAST A PORTION OF SAID VOICE SIGNALS PHASE SHIFTED TO A THIRD ELECTRODE OF SAID OTHER DEVICE, AND MEANS ALSO COUPLED TO THE OUTPUT ELECTRODE OF SAID ONE DEVICE FOR BROADCASTING SOUNDS CORRESPONDING TO SAID VOICE FREQUENCIES LESS SAID CANCELED BAND WIDTH.
Claim 3
Dependent Claim
95 words
A MIXER CIRCUIT FOR COMBINING TWO ELECTRICAL SIGNALS COMPRISING A PAIR OF TRANSISTORS, ONE OF SAID TRANSISTORS HAVING AN INPUT ELECTRODE COUPLED TO BE ENERGIZED BY ONE OF SAID SIGNALS AND AN OUTPUT ELECTRODE COUPLED TO AN INPUT ELECTRODE OF THE OTHER OF SAID TRANSISTORS, AN OUTPUT ELECTRODE OF SAID OTHER TRANSISTOR BEING CONNECTED TO CONTROL THE BIAS ON A THIRD ELECTRODE OF SAID ONE TRANSISTOR, MEANS FOR APPLYING THE OTHER OF SAID SIGNALS TO A THIRD ELECTRODE OF SAID OTHER TRANSISTOR, AND AN OUTPUT CIRCUIT COUPLED TO THE OUTPUT ELECTRODE OF SAID ONE TRANSISTOR.
Claim 4
Dependent Claim
95 words
A MIXER CIRCUIT FOR COMBINING TWO ELECTRICAL SIGNALS COMPRISING A PAIR OF TRANSISTORS, ONE OF SAID TRANSISTORS HAVING AN INPUT ELECTRODE COUPLED TO BE ENERGIZED BY ONE OF SAID SIGNALS AND AN OUTPUT ELECTRODE COUPLED TO AN INPUT ELECTRODE OF THE OTHER OF SAID TRANSISTORS, AN OUTPUT ELECTRODE OF SAID OTHER TRANSISTOR BEING CONNECTED TO CONTROL THE BIAS ON A THIRD ELECTRODE OF SAID ONE TRANSISTOR, MEANS FOR APPLYING THE OTHER OF SAID SIGNALS TO A THIRD ELECTRODE OF SAID OTHER TRANSISTOR, AND AN OUTPUT CIRCUIT COUPLED TO THE OUTPUT ELECTRODE OF SAID ONE TRANSISTOR.
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) | 1966-09-30 | 1967-04-01 | 1967-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-09-30 | 1971-04-01 | 1971-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-09-30 | 1975-04-01 | 1975-10-01 | $7700.00 | Window Closed / Lapsed |