US3569851A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical filter circuit
Assignee: Siemens AG
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Filing: 1968-04-19
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Granted: 1971-03-09
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Expires: 1988-04-19
Abstract
Abstract An electrical filter comprises an amplifier with a pair of pushpull terminals on its input and/or output side. A frequencyselective network forms a negative feedback from the output to the input of the amplifier. A bridge circuit constituted by circuit components of the network as well as by the pair of pushpull terminals, has branches whose respective reactive impedances differ from one another as regards their dependence upon frequency so as to conjointly define a pair of null points for the damping function of the transmitting attenuation of the filter.
Inventors
- 👤 Andreas Jaumann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:25
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/126; G; G06; G06G; G06G7/00; G06G7/48; G06G7/62; G06G7/623; H03F; H03F1/00; H03F1/34; H03F1/36; H03F3/00; H03F3/189
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
147 words
An electrical filter circuit, comprising an operational amplifier having input means and output means and a feedback path from said output means to said input means, said operational amplifier comprising: at least a pair of differential terminals; and a frequency selective network in the feedback path of said operational amplifier, said network comprising only resistors and capacitors, and at least one bridge circuit having a plurality of branches, each of two of the branches of said bridge circuit comprising at least one resistor and at least one capacitor connected to each other, and another two of the branches of said bridge circuit including said pair of differential terminals whereby the resistor and capacitor branches of saId bridge circuit are so variable with regard to the frequency dependence of their impedance that a pair of null points are thereby determined for the damping function of the transmission attenuation.
Claim 2
Dependent Claim
147 words
An electrical filter circuit, comprising an operational amplifier having input means and output means and a feedback path from said output means to said input means, said operational amplifier comprising: at least a pair of differential terminals; and a frequency selective network in the feedback path of said operational amplifier, said network comprising only resistors and capacitors, and at least one bridge circuit having a plurality of branches, each of two of the branches of said bridge circuit comprising at least one resistor and at least one capacitor connected to each other, and another two of the branches of said bridge circuit including said pair of differential terminals whereby the resistor and capacitor branches of saId bridge circuit are so variable with regard to the frequency dependence of their impedance that a pair of null points are thereby determined for the damping function of the transmission attenuation.
Claim 3
Dependent Claim
45 words
An electrical filter circuit as claimed in claim 1, wherein one of the branches of the bridge circuit comprises resistor and capacitor means connected in series circuit arrangement and another of the branches of said bridge circuit comprises resistor and capacitor means in parallel connection.
Claim 4
Dependent Claim
58 words
An electrical filter circuit as claimed in claim 1, wherein the output means of said operational amplifier comprises a pair of output terminals, and one of the branches of the bridge circuit comprises a resistor having a tap connected to an output terminal of said operational amplifier and a pole point pair of the damping function are determined.
Claim 5
Dependent Claim
84 words
An electrical filter circuit as claimed in claim 1, wherein the input means of said operational amplifier comprises a differential input and the output means of said operational amplifier comprises a differential output, and the network in the feedback path of said operational amplifier comprises a first bridge circuit connected to said input and a second bridge circuit connected to said output, each of said first and second bridge circuits determining a pair of null points for the damping function of the transmission attenuation.
Claim 6
Dependent Claim
28 words
An electrical filter circuit as claimed in claim 4, wherein at least one of said first and second bridge circuits has a tap defining a pole point pair.
Claim 7
Dependent Claim
85 words
An electrical filter circuit as claimed in claim 1, further comprising a subordinate pair of connecting terminals in the feedback path of said operational amplifier, and wherein the network in the feedback path of said operational amplifier comprises a pair of bridge circuits connected in parallel with each other, one of said bridge circuits being connected in said feedback path and the other of said bridge circuits being connected to a terminal of said subordinate pair of connecting terminals and defining a pole point pair.
Claim 8
Dependent Claim
77 words
An electrical filter circuit as claimed in claim 1, further comprising coupling resistors, and wherein the input means of said operational amplifier comprises a pair of input terminals and the output means of said operational amplifier comprises a pair of output terminals and the bridge circuit of said network has a plurality of bridge points, and wherein one of the terminals of said input and output means is connected to different bridge points via said coupling resistors.
Claim 9
Dependent Claim
42 words
An electrical filter circuit as claimed in claim 7, wherein there are at least two feedback paths from the output means to the input means of said operational amplifier and said feedback paths are connected to various ones of said bridge points.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |