US3708700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplifier circuit
Assignee: Telefunken Electronic GmbH
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Filing: 1971-01-28
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Granted: 1973-01-02
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Expires: 1991-01-28
Abstract
Abstract An amplifier circuit comprises a common-emitter connected transistor into the collector path of which is connected a first resistance also connected to a voltage source and a voltage divider for adjusting the base emitter direct voltage and including a series connection of a second resistance and a diode, the second resistance being connected to the voltage source and the diode being connected in parallel with the base-to-emitter path of the transistor.
Inventors
- 👤 H Moser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:16
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/286; H03K3/2893; H03F; H03F1/00; H03F1/30; H03F1/302
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
102 words
An amplifier circuit responsive to an external condition comprising a common-emitter connected transistor, a first resistance connected in the collector path of said transistor and to a source of supply voltage, and a voltage divider for adjusting the base-emitter direct voltage of said transistor, said voltage divider including a second resistance connected to said source of supply voltage and a diode connected in series with said second resistance, said diode being in parallel with the base-emitter path of said transistor, and said first resistance and said second resistance being oppositely variable in ohmic value in response to change in the external condition.
Claim 2
Dependent Claim
102 words
An amplifier circuit responsive to an external condition comprising a common-emitter connected transistor, a first resistance connected in the collector path of said transistor and to a source of supply voltage, and a voltage divider for adjusting the base-emitter direct voltage of said transistor, said voltage divider including a second resistance connected to said source of supply voltage and a diode connected in series with said second resistance, said diode being in parallel with the base-emitter path of said transistor, and said first resistance and said second resistance being oppositely variable in ohmic value in response to change in the external condition.
Claim 3
Dependent Claim
71 words
A circuit as defined in claim 1, wherein said first and second resistances are respective variable resistors whose resistance values vary oppositely with respect to one another in response to changes in the external condition and whose resistance values cause the current flowing through said voltage divider and said collector path of said transistor to be substantially equal in the absence of change in the external condition from a given value.
Claim 4
Dependent Claim
48 words
A circuit as defined in claim 2, wherein said first and second resistors comprise respective magnetic diodes whose ohmic resistance values vary oppositely with respect to one another in response to variation of a magnetic field acting on said magnetic diodes, the magnetic field being the external condition.
Claim 5
Dependent Claim
28 words
A circuit as defined in claim 2, wherein said diode comprises the base-emitter path of a further transistor which has its collector electrode shorted to its base electrode.
Claim 6
Dependent Claim
38 words
A circuit as defined in claim 2, wherein the collector resistance of said transistor is less than or equal to the resistance value of said second resistance under the influence of the external condition of a given value.
Claim 7
Dependent Claim
36 words
A circuit as defined in claim 2, further comprising a threshold switch connected to said transistor and operating to change its switching state when a specific potential is reached at the collector electrode of said transistor.
Claim 8
Dependent Claim
15 words
A circuit as defined in claim 6, wherein said threshold switch comprises a Schmitt trigger.
Claim 9
Dependent Claim
15 words
A circuit as defined in claim 2, wherein said first And second resistors comprise thermistors.
Claim 10
Dependent Claim
16 words
A circuit as defined in claim 2, wherein said first and second resistors comprise P.T.C. resistors.
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) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |