Patent US4303891A successfully refreshed from Google Patents.
US4303891A
Expired / Lapsed
US
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Monolithic integrated circuit with frequency dependent amplification
Assignee: ITT Inc
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Filing: 1979-12-10
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Granted: 1981-12-01
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Expires: 1999-12-10
Abstract
Abstract A sound amplifier is provided in a monolithic integrated circuit form and includes tone compensated volume control achieved by the use of emitter followers and a capacitor connected at one side to ground.
Inventors
- 👤 Gerhard Achtstaetter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:41
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1213; H03G; H03G5/00; H03G5/02; H03G5/04; H03G5/10; H03G9/00; H03G9/02; H03G9/12; H03G9/14
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
180 words
A monolithic integrated circuit with frequency dependent amplification, employing a first transistor operated as an emitter follower, and a capacitor applied with one side to the zero point of the circuit, wherein the improvement comprises: the capacitor being connected between the emitter of the first transistor which is operated as an emitter follower and the zero point of the circuit; a first resistor connecting the collector of the first transistor to a point of constant potential; the collector of the first transistor being applied to the base of a second transistor operated as an emitter follower, with the emitter thereof being connected to the base of the first transistor; the emitter of a third transistor operated as an emitter follower, being connected across a second resistor to the emitter of said second transistor; the base of said third transistor being applied to the point of constant potential; and a signal input at the base of the second transistor, and a signal output being the collector of one of said second and third transistors, whereby amplification of bass frequencies is increased.
Claim 2
Dependent Claim
180 words
A monolithic integrated circuit with frequency dependent amplification, employing a first transistor operated as an emitter follower, and a capacitor applied with one side to the zero point of the circuit, wherein the improvement comprises: the capacitor being connected between the emitter of the first transistor which is operated as an emitter follower and the zero point of the circuit; a first resistor connecting the collector of the first transistor to a point of constant potential; the collector of the first transistor being applied to the base of a second transistor operated as an emitter follower, with the emitter thereof being connected to the base of the first transistor; the emitter of a third transistor operated as an emitter follower, being connected across a second resistor to the emitter of said second transistor; the base of said third transistor being applied to the point of constant potential; and a signal input at the base of the second transistor, and a signal output being the collector of one of said second and third transistors, whereby amplification of bass frequencies is increased.
Claim 3
Dependent Claim
125 words
Circuit as claimed in claim 1, additionally comprising: a further capacitor connecting the emitter of a fourth transistor operated as an emitter follower, to the zero point of the circuit, with the collector thereof being applied to the collector of said second transistor; the common connecting point of the base of said second and the collector of said first transistor as well as of said first resistor is applied across a third resistor to said signal input and to the base of said fourth transistor; the collector of said third transistor is applied to the zero point of the circuit; and the collectors connected together of both said second and the fourth transistor serve as the signal output whereby amplification of treble frequencies is increased.
References Cited (Backward Citations)
US3247462A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-30 | 1985-06-01 | 1985-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-30 | 1989-06-01 | 1989-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-30 | 1993-06-01 | 1993-12-01 | $7700.00 | Window Closed / Lapsed |