US3838353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplifier with failsafe predertermined gain
Assignee: Bombardier Transportation Holdings USA Inc
•
Filing: 1973-08-15
•
Granted: 1974-09-24
•
Expires: 1993-08-15
Abstract
Abstract An amplifier in which the feedback impedance includes a four terminal capacitor, and in which the input impedance is connected to a source of operating potential. The use of a four terminal capacitor as a feedback element compensates for the failure mode of the amplifier in which the opening of the feedback element results in infinite AC gain of the amplifier. The connection of the signal input impedance to a source of operating potential compensates for the failure mode of the amplifier in which the input impedance shorts, which normally results in infinite AC gain of the amplifier.
Inventors
- 👤 T Matty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:08
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/34
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
115 words
In an amplifier circuit having failsafe predetermined gain, the combination comprising: a circuit input terminal; a circuit output terminal; a source of operating potential; an amplifier having first and second input terminals and an output terminal, with the first input terminal being connected to said circuit input terminal; a capacitor having first, second, third and fourth terminals, with the first terminal being connected to the output terminal of said amplifier, the second terminal being connected to the second input terminal of said amplifier, and the third terminal being connected to said circuit output terminal; and a first impedance means connected between the fourth terminal of said four terminal capacitor and said source of operating potential.
Claim 2
Dependent Claim
115 words
In an amplifier circuit having failsafe predetermined gain, the combination comprising: a circuit input terminal; a circuit output terminal; a source of operating potential; an amplifier having first and second input terminals and an output terminal, with the first input terminal being connected to said circuit input terminal; a capacitor having first, second, third and fourth terminals, with the first terminal being connected to the output terminal of said amplifier, the second terminal being connected to the second input terminal of said amplifier, and the third terminal being connected to said circuit output terminal; and a first impedance means connected between the fourth terminal of said four terminal capacitor and said source of operating potential.
Claim 3
Dependent Claim
23 words
The combination claimed in claim 1 including: a second impedance means connected between the third and fourth terminals of said four terminal capacitor.
Claim 4
Dependent Claim
30 words
The combination claimed in claim 2 wherein said first impedance means comprises a first resistor connected in series with a capacitor, and said second impedance means comprises a second resistor.
Claim 5
Dependent Claim
157 words
In a failsafe amplifier circuit in which the alternating current gain does not exceed a predetermined level irrespective of any failure mode, the combination comprising: a circuit input terminal; a circuit output terminal; a source of operating potential; an amplifier having a first input terminal connected to said circuit input terminal and also having a second input terminal and an output terminal; a four terminal capacitor having the first terminal thereof connected to the output terminal of said amplifier and the second terminal thereof connected to the second input terminal of said amplifier and the third terminal thereof connected to said circuit output terminal; a first resistor connected between the third and fourth terminals of said four terminal capacitor; a two terminal capacitor having one terminal thereof connected to the fourth terminal of said four terminal capacitor; and a second resistor connected between the remaining terminal of said two terminal capacitor and said source of operating potential.
Claim 6
Dependent Claim
157 words
In a failsafe amplifier circuit in which the alternating current gain does not exceed a predetermined level irrespective of any failure mode, the combination comprising: a circuit input terminal; a circuit output terminal; a source of operating potential; an amplifier having a first input terminal connected to said circuit input terminal and also having a second input terminal and an output terminal; a four terminal capacitor having the first terminal thereof connected to the output terminal of said amplifier and the second terminal thereof connected to the second input terminal of said amplifier and the third terminal thereof connected to said circuit output terminal; a first resistor connected between the third and fourth terminals of said four terminal capacitor; a two terminal capacitor having one terminal thereof connected to the fourth terminal of said four terminal capacitor; and a second resistor connected between the remaining terminal of said two terminal capacitor and said source of operating potential.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |