US3729588A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistorized amplifier
Assignee: American Danish Oticon AS
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Filing: 1969-12-29
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Granted: 1973-04-24
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Expires: 1989-12-29
Abstract
Abstract The present invention relates to a transistorized audio amplifier especially for hearing aid equipment having an input stage and an output stage with a sound reproducer in the output stage between the collector of the output transistor and one battery terminal and with negative DC feedback between the output stage and the input stage. The base-emitter diode of the input is connected in such a manner as to provide stabilization of the voltage drop across the sound reproducer.
Inventors
- 👤 O Berland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:51
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/02; H03G3/04; H03G3/10; H03G3/12; H03F; H03F1/00; H03F1/30; H03F1/302; H03F1/34; H03F3/00; H03F3/181; H03F3/183; H10; H10D; H10D99/00; H04; H04R; H04R2225/00; H04R2225/33; H04R25/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
221 words
In a battery operated amplifier with transistors having an input stage with an input between one terminal of a battery and the base of an input transistor and an output having a sound reproducer connected between one terminal of the battery and the collector of an output transistor, and with negative DC feedback path between the output transistor and the input transistor, the improvement comprising the emitter of the base-emitter diode of the input transistor being connected with the same battery terminal as the sound reproducer so that the feedback maintains the collector potential of the output transistor relatively constant with respect to the potential at the battery terminal connected with the emitter of the input transistor; and a voltage adjusting network between the collector of the output transistor and the feedback path to compensate for the DC voltage difference between the output and input of the amplifier, comprising a diode in series with a resistor connected between the collector of the output transistor and the emitter thereof and shunted with an adjustable voltage divider having a point at which the feedback path is connected, the voltage of the point being adjustable to a value which added to the voltage drop across thE sound reproducer is substantially equal to the voltage drop between the base and emitter of the input transistor.
Claim 2
Dependent Claim
221 words
In a battery operated amplifier with transistors having an input stage with an input between one terminal of a battery and the base of an input transistor and an output having a sound reproducer connected between one terminal of the battery and the collector of an output transistor, and with negative DC feedback path between the output transistor and the input transistor, the improvement comprising the emitter of the base-emitter diode of the input transistor being connected with the same battery terminal as the sound reproducer so that the feedback maintains the collector potential of the output transistor relatively constant with respect to the potential at the battery terminal connected with the emitter of the input transistor; and a voltage adjusting network between the collector of the output transistor and the feedback path to compensate for the DC voltage difference between the output and input of the amplifier, comprising a diode in series with a resistor connected between the collector of the output transistor and the emitter thereof and shunted with an adjustable voltage divider having a point at which the feedback path is connected, the voltage of the point being adjustable to a value which added to the voltage drop across thE sound reproducer is substantially equal to the voltage drop between the base and emitter of the input transistor.
Claim 3
Dependent Claim
15 words
An amplifier as claimed in claim 1 in which the diode is a silicium diode.
Claim 4
Dependent Claim
37 words
An amplifier as claimed in claim 1 in which the feedback path includes resistors which are of so low value that the base currents of the input transistor only cause a small voltage drop across these resistors.
Claim 5
Dependent Claim
20 words
An amplifier as claimed in claim 1 in which the voltage adjusting network includes resistors which are of low values.
Claim 6
Dependent Claim
198 words
In a battery operated amplifier with transistors having an input stage with an input between one terminal of the battery and the base of an input transistor and an output stage having a sound reproducer which is connected between one terminal of the battery and the collector of an output transistor and with a negative feedback path between the output transistor and the input transistor the improvement that the input transistor and the output transistor are of opposite polarity with the emitter of the input transistor connected to the same battery terminal as that to which the collector of the output transistor is connected through the sound reproducer, a voltage adjusting network between the collector of the output transistor and the feedback path to compensate for the DC voltage difference between the output and input of the amplifier, comprising a diode in series with a resistor shunted with an adjustable voltage divider having a point at which the feedback path is connected, the voltage of the point being adjustable to a value which added to the voltage drop across the sound reproducer is substantially equal to the voltage drop between the base and emitter of the input transistor.
Claim 7
Dependent Claim
198 words
In a battery operated amplifier with transistors having an input stage with an input between one terminal of the battery and the base of an input transistor and an output stage having a sound reproducer which is connected between one terminal of the battery and the collector of an output transistor and with a negative feedback path between the output transistor and the input transistor the improvement that the input transistor and the output transistor are of opposite polarity with the emitter of the input transistor connected to the same battery terminal as that to which the collector of the output transistor is connected through the sound reproducer, a voltage adjusting network between the collector of the output transistor and the feedback path to compensate for the DC voltage difference between the output and input of the amplifier, comprising a diode in series with a resistor shunted with an adjustable voltage divider having a point at which the feedback path is connected, the voltage of the point being adjustable to a value which added to the voltage drop across the sound reproducer is substantially equal to the voltage drop between the base and emitter of the input transistor.
Claim 8
Dependent Claim
15 words
An amplifier as claimed in claim 5 in which the diode is a silicium diode.
Claim 9
Dependent Claim
238 words
In a battery operated amplifier with transistors having an input stage with an input between one terminal of the battery and the base of an input transistor and an output stage having a sound reproducer which is connected between one terminal of the battery and the collector of an output transistor, and with a negative feedback path between the output transistor and the input transistor, the improvement that the input transistor and the output transistor are of opposite polarity with the emitter of the input transistor connected with the same battery terminal as that with which the collector of the output transistor is connected through the sound reproducer, a voltage adjusting network provided between the collector of the output transistor and the feedback path to compensate for the DC voltage difference between the output and input of the amplifier, said voltage adjusting network comprising a diode having substantially constant voltage drop which at least partially is used to compensate for the voltage difference between the output and input of the amplifier, said diode being a base emitter diode of a transistor which constitutes an amplification stage between the input stage and the output stage and to the base of which the negative feedback path from the input stage is connected and in series with which a resistor is provided in a voltage adjusting network which is connected with the sound reproducer and the collector of the output transistor.
Claim 10
Dependent Claim
238 words
In a battery operated amplifier with transistors having an input stage with an input between one terminal of the battery and the base of an input transistor and an output stage having a sound reproducer which is connected between one terminal of the battery and the collector of an output transistor, and with a negative feedback path between the output transistor and the input transistor, the improvement that the input transistor and the output transistor are of opposite polarity with the emitter of the input transistor connected with the same battery terminal as that with which the collector of the output transistor is connected through the sound reproducer, a voltage adjusting network provided between the collector of the output transistor and the feedback path to compensate for the DC voltage difference between the output and input of the amplifier, said voltage adjusting network comprising a diode having substantially constant voltage drop which at least partially is used to compensate for the voltage difference between the output and input of the amplifier, said diode being a base emitter diode of a transistor which constitutes an amplification stage between the input stage and the output stage and to the base of which the negative feedback path from the input stage is connected and in series with which a resistor is provided in a voltage adjusting network which is connected with the sound reproducer and the collector of the output transistor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |