US3177441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjustment of acoustic balance in stereophonic reproducing devices
Assignee: NORTH AMERICAN PHILLIPS COMPAN
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Filing: 1961-06-09
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Granted: 1965-04-06
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Expires: 1981-06-09
Abstract
No abstract record available.
Inventors
- 👤 Everaars Pieter Roelof
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:46
CPC Classifications
H; H04; H04S; H04S7/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
137 words
A STEREOPHONIC SIGNAL REPRODUCING SYSTEM COMPRISING FIRST AND SECOND AMPLIFIER CHANNELS, EACH OF SAID CHANNELS COMPRISING INPUT AND OUTPUT AMPLIFIER STAGES, AN AMPLIFYING DEVICE IN EACH OF SAID STAGES HAVING AT LEAST AN INPUT ELECTRODE, AN OUTPUT ELECTRODE, AND A COMMON ELECTRODE, MEANS APPLYING SEPARATE SIGNALS TO THE INPUT ELECTRODES OF THE AMPLIFYING DEVICES OF SAID INPUT STAGES, A POINT OF REFERENCE POTENTIAL, SEPARATE UNBYPASSED RESISTORS CONNECTED BETWEEN THE COMMON ELECTRODE OF EACH AMPLIFIER DEVICE AND SAID POINT OF REFERENCE POTENTIAL FOR PROVIDING NEGATIVE FEEDBACK IN EACH OF SAID STAGES, POSITIVE FEEDBACK MEANS COMPRISING SEPARATE TAPPED IMPEDANCES CONNECTED BETWEEN THE COMMON ELECTRODES OF THE AMPLIFIER DEVICES OF THE OUTPUT AND INPUT STAGES OF EACH CHANNEL, POTENTIOMETER MEANS CONNECTED BETWEEN THE TAPS OF SAID IMPEDANCES, AND MEANS CONNECTING THE MOVABLE TAPE OF SAID POTENTIOMETER MEANS TO SAID POINT.
Claim 2
Dependent Claim
137 words
A STEREOPHONIC SIGNAL REPRODUCING SYSTEM COMPRISING FIRST AND SECOND AMPLIFIER CHANNELS, EACH OF SAID CHANNELS COMPRISING INPUT AND OUTPUT AMPLIFIER STAGES, AN AMPLIFYING DEVICE IN EACH OF SAID STAGES HAVING AT LEAST AN INPUT ELECTRODE, AN OUTPUT ELECTRODE, AND A COMMON ELECTRODE, MEANS APPLYING SEPARATE SIGNALS TO THE INPUT ELECTRODES OF THE AMPLIFYING DEVICES OF SAID INPUT STAGES, A POINT OF REFERENCE POTENTIAL, SEPARATE UNBYPASSED RESISTORS CONNECTED BETWEEN THE COMMON ELECTRODE OF EACH AMPLIFIER DEVICE AND SAID POINT OF REFERENCE POTENTIAL FOR PROVIDING NEGATIVE FEEDBACK IN EACH OF SAID STAGES, POSITIVE FEEDBACK MEANS COMPRISING SEPARATE TAPPED IMPEDANCES CONNECTED BETWEEN THE COMMON ELECTRODES OF THE AMPLIFIER DEVICES OF THE OUTPUT AND INPUT STAGES OF EACH CHANNEL, POTENTIOMETER MEANS CONNECTED BETWEEN THE TAPS OF SAID IMPEDANCES, AND MEANS CONNECTING THE MOVABLE TAPE OF SAID POTENTIOMETER MEANS TO SAID POINT.
References Cited (Backward Citations)
US2313098A
Cited
GB814646A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-04-05 | 1968-10-05 | 1969-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-04-05 | 1972-10-05 | 1973-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-04-05 | 1976-10-05 | 1977-04-06 | $7700.00 | Window Closed / Lapsed |