Patent US4387270A successfully refreshed from Google Patents.
US4387270A
Expired / Lapsed
US
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Method of harmonizing the impedances of an audio amplifier and loudspeaker interconnected therewith
Assignee: Toshiba Corp
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Filing: 1980-11-28
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Granted: 1983-06-07
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Expires: 2000-11-28
Abstract
Abstract A method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith, the audio amplifier including a line amplifier and a positive feedback circuit for compensating for the counter electromotive force of the loudspeaker. A voice coil of the loudspeaker is mechanically driven for generating an electric signal at input terminals of the loudspeaker. Then, the amplification degree of the line amplifier or the positive feedback circuit is adjusted to reduce the signal voltage between the input terminals of the loudespeaker to a minimum, during the circulation of the generated signal through the positive feedback circuit and the line amplifier.
Inventors
- 👤 Hideki Sakano
- 👤 Shigeru Todokoro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:31
CPC Classifications
H; H04; H04R; H04R3/00; H04R3/002; H03; H03F; H03F1/00; H03F1/56; H03F3/00; H03F3/181; H04B; H04B3/00; H04B3/02; H04B3/40
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
94 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith, the audio amplifier including a line amplifier and a positive feedback circuit for compensating for the counter electromotive force of the loudspeaker, the method comprising: mechanically driving a voice coil of the loudspeaker to generate an electrical signal; and minimizing the voltage between the input terminals of the loudspeaker by adjusting the amplification degree of the line amplifier or the positive feedback circuit during the circulation of the generated signal through the positive feedback circuit and the line amplifier.
Claim 2
Independent Claim
94 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith, the audio amplifier including a line amplifier and a positive feedback circuit for compensating for the counter electromotive force of the loudspeaker, the method comprising: mechanically driving a voice coil of the loudspeaker to generate an electrical signal; and minimizing the voltage between the input terminals of the loudspeaker by adjusting the amplification degree of the line amplifier or the positive feedback circuit during the circulation of the generated signal through the positive feedback circuit and the line amplifier.
Claim 3
Dependent Claim
40 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith according to claim 1 wherein said step of mechanically driving the voice coil of the loudspeaker is accomplished by tapping the diaphragm of the loudspeaker.
Claim 4
Dependent Claim
43 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith according to claim 1 wherein said step of mechanically driving the voice coil of the loudspeaker is accomplished by a sound acting on the diaphragm of the loudspeaker.
Claim 5
Dependent Claim
32 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith according to claim 3 wherein the sound is produced by another loudspeaker connected to another audio amplifier.
Claim 6
Dependent Claim
80 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker connected therewith according to claim 4 wherein said latter audio amplifier and said latter loudspeaker constitute a first audio amplifier and a first loudspeaker and wherein said method includes the step of utilizing a second audio amplifier and a second loudspeaker to complete a set of stereo apparatus with said first audio amplifier and first loudspeaker and wherein said second audio amplifier constitutes said another audio amplifier.
Claim 7
Dependent Claim
59 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith according to the claim 1 wherein said step of minimizing the voltage between the input terminals of the loudspeaker includes connecting a voltage sensitive indicator between the input terminals of the loudspeaker before the step of mechanically driving a voice coil of the loudspeaker.
Claim 8
Dependent Claim
26 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith according to the claim 6 wherein the indicator is a voltmeter.
Claim 9
Dependent Claim
27 words
The method of harmonizing the impedances of an audio amplifier and a loudspeaker interconnected therewith according to claim 6 wherein the indicator is a light emitting diode.
References Cited (Backward Citations)
US3821473A
Cited
US3798374A
Cited
US4180706A
Cited
US4287389A
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US4276443A
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US4335274A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-06 | 1986-12-06 | 1987-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-06 | 1990-12-06 | 1991-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-06 | 1994-12-06 | 1995-06-07 | $7700.00 | Window Closed / Lapsed |