Patent US2096231A successfully refreshed from Google Patents.
Patent US3761832A successfully refreshed from Google Patents.
US3761832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preamplifier for music and voice
Assignee: U S Holding Co Inc
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Filing: 1971-07-21
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Granted: 1973-09-25
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Expires: 1991-07-21
Abstract
Abstract There is disclosed a preamplifier for both music and voice that will enable achieving the best quality for both music and voice. The preamplifier includes an amplifier circuit for music whose components are adjusted or selected to provide the desired music quality and a distinct amplifier circuit for voice whose components are adjusted or selected to provide the desired voice quality. The output of these two distinct amplifier circuits are coupled to a common amplifier stage prior to being coupled to a common power amplifier. With this arrangement, a simplified automatic gain control circuit driven by the output signal of the power amplifier can be provided for the voice amplifier circuit.
Inventors
- 👤 D Blattenberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:20
CPC Classifications
H; H03; H03G; H03G5/00; H03G5/02; H03G5/04; H03G5/10; H03F; H03F3/00; H03F3/68; H03G3/00; H03G3/20; H03G3/30; H03G3/3005; H03G3/301; H03G3/3015
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
340 words
A preamplifier for both voice and music inputs comprising: a first source of voice; a second source of music; a first amplifier means coupled to said first source; a second amplifier means coupled to said second source; a third amplifier means coupled in common to the output of said first and second amplifier means to provide improved quality voice and music for coupling to a utilization device; said first amplifier means including a positive voltage power supply, a ground potential, and a first n-type field effect transistor having its gate coupled to said first source, its drain coupled to said power supply through a first load resistor and its source coupled to said ground potential; said second amplifier means including a second n-type field effect transistor having its gate coupled to said second source, its drain coupled to said power supply through a second load resistor and its source coupled to said ground potential; said third amplifier means including a first npn transistor having its base coupled to the drain of both said first and second field effect transistors, its emitter coupled to said ground potential and its collector coupled to said utilization device and said power supply through a third load resistor; a power amplifier having its input coupled to the collector of said first npn transistor and its output coupled to said utilization device; a circuit having a semiconductor diode coupled to the output of said power amplifier to produce a direct current automatic gain control signal; a second npn transistor having its emitter coupled to said ground potential, its collector coupled to said first source and its base coupled to said semiconductor diode, said second npn transistor being responsive to said automatic gain control signal; and a third n-type field effect transistor having its gate coupled to said first source and the collector of said second npn transistor, its source coupled to said ground potential and its drain coupled to said power supply through a fourth load resistor and the gate of said first field effect transistor.
Claim 2
Dependent Claim
340 words
A preamplifier for both voice and music inputs comprising: a first source of voice; a second source of music; a first amplifier means coupled to said first source; a second amplifier means coupled to said second source; a third amplifier means coupled in common to the output of said first and second amplifier means to provide improved quality voice and music for coupling to a utilization device; said first amplifier means including a positive voltage power supply, a ground potential, and a first n-type field effect transistor having its gate coupled to said first source, its drain coupled to said power supply through a first load resistor and its source coupled to said ground potential; said second amplifier means including a second n-type field effect transistor having its gate coupled to said second source, its drain coupled to said power supply through a second load resistor and its source coupled to said ground potential; said third amplifier means including a first npn transistor having its base coupled to the drain of both said first and second field effect transistors, its emitter coupled to said ground potential and its collector coupled to said utilization device and said power supply through a third load resistor; a power amplifier having its input coupled to the collector of said first npn transistor and its output coupled to said utilization device; a circuit having a semiconductor diode coupled to the output of said power amplifier to produce a direct current automatic gain control signal; a second npn transistor having its emitter coupled to said ground potential, its collector coupled to said first source and its base coupled to said semiconductor diode, said second npn transistor being responsive to said automatic gain control signal; and a third n-type field effect transistor having its gate coupled to said first source and the collector of said second npn transistor, its source coupled to said ground potential and its drain coupled to said power supply through a fourth load resistor and the gate of said first field effect transistor.
Claim 3
Dependent Claim
108 words
A preamplifier according to claim 1, further including a first capacitor coupled between the drain of said first field effect transistor and said ground potential having a value selected to provide the best voice quality; a series circuit including a second capacitor and a first potentiometer, said series circuit being coupled between the drain of said second field effect transistor and said ground potential to adjust the treble cuts; and a parallel circuit including a third capacitor and a second potentiometer, said parallel circuit being coupled between the drain of said second field effect transistor and the base of said first npn transistor to adjust the base cuts.
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) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |