US4051385A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active networks and signalling equipment
Assignee: Post Office
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Filing: 1976-06-09
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Granted: 1977-09-27
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Expires: 1996-06-09
Abstract
Abstract An active network incorporating a gyrator, having a first and a second operational amplifier each said operational amplifier having an inverting input and a non-inverting input, the inverting inputs of said first and said second operational amplifiers being directly connected, and wherein the outputs of said first and said second operational amplifiers are resistively connected to the inverting inputs of said operational amplifiers, an input terminal is connected to said non-inverting input of said first operational amplifier which said input terminal is connected resistively to said output of said second operational amplifier, said output of said first operational amplifier is capacitively coupled to said non-inverting input of said second operational amplifier and said non-inverting input of said second operational amplifier is resistively connected to earth.
Inventors
- 👤 Philip Ernest Greenaway
- 👤 John Mortimer Rollett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:46
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/08; H03H11/40; H03H11/42; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
127 words
An active network incorporating a gyrator, having a first and a second operational amplifier each said operational amplifier having an inverting input and a non-inverting input, the inverting inputs of said first and said second operational amplifiers being directly connected, and wherein the outputs of each of said first and said second operational amplifiers are resistively connected to the inverting inputs of their respective operational amplifiers, an input terminal connected to said non-inverting input of said first operational amplifier which said input terminal is connected resistively to said output of said second operational amplifier, said output of said first operational amplifier is capacitively coupled to said non-inverting input of said second operational amplifier and said non-inverting input of said second operational amplifier is resistively connected to earth.
Claim 2
Dependent Claim
127 words
An active network incorporating a gyrator, having a first and a second operational amplifier each said operational amplifier having an inverting input and a non-inverting input, the inverting inputs of said first and said second operational amplifiers being directly connected, and wherein the outputs of each of said first and said second operational amplifiers are resistively connected to the inverting inputs of their respective operational amplifiers, an input terminal connected to said non-inverting input of said first operational amplifier which said input terminal is connected resistively to said output of said second operational amplifier, said output of said first operational amplifier is capacitively coupled to said non-inverting input of said second operational amplifier and said non-inverting input of said second operational amplifier is resistively connected to earth.
Claim 3
Dependent Claim
25 words
An active network as claimed in claim 1 in which an output terminal is directly connected to the output of one of said operational amplifiers.
Claim 4
Dependent Claim
20 words
A series tuned circuit including a capacitor and an inductance simulated by an active network as claimed in claim 1.
Claim 5
Dependent Claim
59 words
A frequency discrimination circuit including a series tuned circuit having an input and an output the inductive portion of which is a gyrator as defined by claim 1; an amplifier having its output connected to the input of said tuned circuit; rectifier means connected to the output of said tuned circuit; and an amplifier connected to said rectifying means.
Claim 6
Dependent Claim
29 words
A high pass "T" filter circuit having a gyrator as defined by claim 1 simulating an inductance connected in series with a capacitor as the leg of the "T".
Claim 7
Dependent Claim
58 words
A frequency detection circuit having a series resonant tuned circuit connected between the input and ground the inductive portion of said tuned circit being a gyrator as defined by claim 1; a detector comprising a differential input operational amplifier connected to the output of said tuned circuit; and a trigger circuit coupled to the output of said detector.
References Cited (Backward Citations)
US3736517A
Cited
US3824496A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-26 | 1981-03-28 | 1981-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-26 | 1985-03-28 | 1985-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-26 | 1989-03-28 | 1989-09-27 | $7700.00 | Window Closed / Lapsed |