US3647969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motional feedback amplifier
Assignee: Individual
•
Filing: 1969-08-28
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Granted: 1972-03-07
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Expires: 1989-08-28
Abstract
Abstract A motional feedback amplifier, having an impedance bridge, one arm of which comprises a loudspeaker and which is balanced at the frequency of the loudspeaker with the diaphragm blocked, comprising a low-pass filter in the feedback loop between the reading terminals of the bridge and the input terminal for the feedback voltage to the amplifier and the characteristic of which is adjusted so as substantially to suppress the feedback voltage in the frequency zone in which the false readings appear and above that zone, a low-frequency corrector in the conventional negative feedback loop, the said filter being preceded by a transistor, two control electrodes of which, are fed with a signal from the reading terminals of the bridge and the output electrode of which delivers the motional feedback signal to the amplifier.
Inventors
- 👤 Tadeusz Korn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:34
CPC Classifications
H; H04; H04R; H04R3/00; H04R3/002; H03; H03F; H03F1/00; H03F1/34
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
173 words
A motional feedback amplifier comprising an impedance bridge for providing said feedback, one arm of said bridge including a loudspeaker, said bridge being balanced with a loudspeaker diaphragm blocked at the resonance frequency of the loudspeaker, a first feedback loop having a low-pass filter provided therein extending between reading terminals of the bridge and an amplifier input terminal for reading the feedback voltage to the amplifier, said amplifier being adapted to substantially suppress the feedback voltage in and above the frequency zone in which any false readings of the bridge appear, and a second feedback loop having a low-frequency corrector provided therein constituting a negative feedback loop of said amplifier, an active transistor element in said first feedback loop preceding said low-pass filter, said element including two control electrodes which form an emitter and a base of the element and which are supplied with a signal froM the reading terminals of the bridge, and an output electrode of the element adapted to deliver the feedback signal to the filter and to the amplifier.
Claim 2
Dependent Claim
173 words
A motional feedback amplifier comprising an impedance bridge for providing said feedback, one arm of said bridge including a loudspeaker, said bridge being balanced with a loudspeaker diaphragm blocked at the resonance frequency of the loudspeaker, a first feedback loop having a low-pass filter provided therein extending between reading terminals of the bridge and an amplifier input terminal for reading the feedback voltage to the amplifier, said amplifier being adapted to substantially suppress the feedback voltage in and above the frequency zone in which any false readings of the bridge appear, and a second feedback loop having a low-frequency corrector provided therein constituting a negative feedback loop of said amplifier, an active transistor element in said first feedback loop preceding said low-pass filter, said element including two control electrodes which form an emitter and a base of the element and which are supplied with a signal froM the reading terminals of the bridge, and an output electrode of the element adapted to deliver the feedback signal to the filter and to the amplifier.
Claim 3
Dependent Claim
51 words
An amplifier as claimed in claim 1, wherein said filter comprises at least two capacitors connected between a signal line and ground, and a capacitor connected in series in the signal line which attenuates the generated signal at very low frequencies and reduces the phase-shift in the operating zone of frequencies.
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) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |