US3750052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjustable frequency-dependent equalizer
Assignee: International Standard Electric Corp
•
Filing: 1971-11-26
•
Granted: 1973-07-31
•
Expires: 1991-11-26
Abstract
Abstract In an adjustable frequency-dependent equalizer for correcting the distortions at the ends of the passband of a filter, which equalizer has an L-, a T- or a bridget T-configuration and comprises a series-resonant circuit, a capacitance is connected in parallel to the inductance of said series-resonant circuit. The two capacitances are varied so that their sum is kept constant.
Inventors
- 👤 P Hermanutz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:16
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/06; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/14; H04B3/143; H04B3/145
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
141 words
In an adjustable frequency-dependent equalizer, having a resistance network of L configuration in which the resistance of the series branch portion of the configuration is bypassed by a series-resonant circuit which includes a main inductance and a main capacitance, the arrangement comprising a first capacitance element portion having provision for capacitance variation and coupled in parallel to said main inductance, and a second capacitance element portion coupled relative to said main capacitance to provide capacitance variation, said first and second capacitance portions being arranged to be interrelated such that the sum of the two variable capacitances remains constant in order to maintain the frequency of the series resonance, said first and second variable capacitances being also arranged for oppositely-directed variations and the equalizing characteristic of the equalizer is thus varied by adjusting the sharpness of resonance of the series resonant circuit.
Claim 2
Dependent Claim
141 words
In an adjustable frequency-dependent equalizer, having a resistance network of L configuration in which the resistance of the series branch portion of the configuration is bypassed by a series-resonant circuit which includes a main inductance and a main capacitance, the arrangement comprising a first capacitance element portion having provision for capacitance variation and coupled in parallel to said main inductance, and a second capacitance element portion coupled relative to said main capacitance to provide capacitance variation, said first and second capacitance portions being arranged to be interrelated such that the sum of the two variable capacitances remains constant in order to maintain the frequency of the series resonance, said first and second variable capacitances being also arranged for oppositely-directed variations and the equalizing characteristic of the equalizer is thus varied by adjusting the sharpness of resonance of the series resonant circuit.
Claim 3
Dependent Claim
20 words
The arrangement according to claim 1 wherein said second capacitance portion replaces said main capacitance of the series resonant circuit.
Claim 4
Dependent Claim
23 words
The arrangement according to claim 2 wherein a differential trimmer is provided for effecting the oppositely-directed variations of said two variable capacitance portions.
Claim 5
Dependent Claim
73 words
The arrangement according to claim 1 wherein said first capacitance includes a fixed capacitance coupled in parallel to said main inductance and a variable capacitance coupled in parallel to said fixed capacitance and to said main inductance, and wherein said second capacitance portion is a variable capacitance, predeterminably variable relative to said variable capacitance in parallel with said main inductance, and coupled in parallel to said main capacitance of said series resonant circuit.
Claim 6
Dependent Claim
141 words
In an adjustable frequency-dependent equalizer, having a resistance network of L configuration in which the resistance of the parallel branch portion of the configuration is bypassed by a series-resonant circuit which includes a main inductancE and a main capacitance, the arrangement comprising a first capacitance element portion having provision for capacitance variation and coupled in parallel to said main inductance and a second capacitance element portion coupled relative to said main capacitance to provide capacitance variation, said first and second capacitance portions being arranged to be interrelated such that the sum of the two variable capacitances remains constant in order to maintain the frequency of the series resonance, said first and second variable capacitances being also arranged for oppositely-directed variations and the equalizing characteristic of the equalizer is thus varied by adjusting the sharpness of resonance of the series resonant circuit.
Claim 7
Dependent Claim
141 words
In an adjustable frequency-dependent equalizer, having a resistance network of L configuration in which the resistance of the parallel branch portion of the configuration is bypassed by a series-resonant circuit which includes a main inductancE and a main capacitance, the arrangement comprising a first capacitance element portion having provision for capacitance variation and coupled in parallel to said main inductance and a second capacitance element portion coupled relative to said main capacitance to provide capacitance variation, said first and second capacitance portions being arranged to be interrelated such that the sum of the two variable capacitances remains constant in order to maintain the frequency of the series resonance, said first and second variable capacitances being also arranged for oppositely-directed variations and the equalizing characteristic of the equalizer is thus varied by adjusting the sharpness of resonance of the series resonant circuit.
Claim 8
Dependent Claim
20 words
The arrangement according to claim 5 wherein said second capacitance portion replaces said main capacitance of the series resonant circuit.
Claim 9
Dependent Claim
23 words
The arrangement according to claim 6 wherein a differential trimmer is provided for effecting the oppositely-directed variations of said two variable capacitance portions.
Claim 10
Dependent Claim
73 words
The arrangement according to claim 5 wherein said first capacitance includes a fixed capacitance coupled in parallel to said main inductance and a variable capacitance coupled in parallel to said fixed capacitance and to said main inductance, and wherein said second capacitance portion is a variable capacitance, predeterminably variable relative to said variable capacitance in parallel with said main inductance, and coupled in parallel to said main capacitance of said series resonant circuit.
Claim 11
Dependent Claim
141 words
In an adjustable frequency-dependent equalizer, having a resistance network of T configuration in which the resistance of the series branch portion of the configuration is bypassed by a series-resonant circuit which includes a main inductance and a main capacitance, the arrangement comprising a first capacitance element portion having provision for capacitance variation and coupled in parallel to said main inductance, and a second capacitance element portion coupled relative to said main capacitance to provide capacitance variation, said first and second capacitance portions being arranged to be interrelated such that the sum of the two variable capacitances remains constant in order to maintain the frequency of the series resonance, said first and second variable capacitances being also arranged for oppositely-directed variations and the equalizing characteristic of the equalizer is thus varied by adjusting the sharpness of resonance of the series resonant circuit.
Claim 12
Dependent Claim
141 words
In an adjustable frequency-dependent equalizer, having a resistance network of T configuration in which the resistance of the series branch portion of the configuration is bypassed by a series-resonant circuit which includes a main inductance and a main capacitance, the arrangement comprising a first capacitance element portion having provision for capacitance variation and coupled in parallel to said main inductance, and a second capacitance element portion coupled relative to said main capacitance to provide capacitance variation, said first and second capacitance portions being arranged to be interrelated such that the sum of the two variable capacitances remains constant in order to maintain the frequency of the series resonance, said first and second variable capacitances being also arranged for oppositely-directed variations and the equalizing characteristic of the equalizer is thus varied by adjusting the sharpness of resonance of the series resonant circuit.
Claim 13
Dependent Claim
20 words
The arrangement according to claim 9 wherein said second capacitance portion replaces said main capacitance of the series resonant circuit.
Claim 14
Dependent Claim
23 words
The arrangement according to claim 10 wherein a differential trimmer is provided for effecting the oppositely-directed variations of said two variable capacitance portions.
Claim 15
Dependent Claim
73 words
The arrangement according to claim 9 wherein said first capacitance includes a fixed capacitance coupled in parallel to said main inductance and a variable capacitance coupled in parallel to said fixed capacitance and to said main inductance, and wherein said second capacitance portion is a variable capacitance, predeterminably variable relative to said variable capacitance in parallel with said main inductance, and coupled in parallel to said main capacitance of said series resonant circuit.
Claim 16
Dependent Claim
60 words
The arrangement according to claim 9 wherein the equalizer circuit is a quasi-constant-Z equalizer of T configuration having a series resonant circuit bypassing the series branch portion of the configuration, and a parallel-resonant circuit in the parallel branch portion of the configuration, and wherein the parallel-resonant circuit is kept invariable, with the bypassing series resonant circuit arrangement being variable only.
Claim 17
Dependent Claim
141 words
In an adjustable frequency-dependent equalizer, having a resistance network of T configuration in which the resistance of the parallel branch portion of the configuration is bypassed by a series-resonant circuit whicH includes a main inductance and a main capacitance, the arrangement comprising a first capacitance element portion having provision for capacitance variation and coupled in parallel to said main inductance, and a second capacitance element portion coupled relative to said main capacitance to provide capacitance variation, said first and second capacitance portions being arranged to be interrelated such that the sum of the two variable capacitances remains constant in order to maintain the frequency of the series resonance, said first and second variable capacitances being also arranged for oppositely-directed variations and the equalizing characteristic of the equalizer is thus varied by adjusting the sharpness of resonance of the series resonant circuit.
Claim 18
Dependent Claim
141 words
In an adjustable frequency-dependent equalizer, having a resistance network of T configuration in which the resistance of the parallel branch portion of the configuration is bypassed by a series-resonant circuit whicH includes a main inductance and a main capacitance, the arrangement comprising a first capacitance element portion having provision for capacitance variation and coupled in parallel to said main inductance, and a second capacitance element portion coupled relative to said main capacitance to provide capacitance variation, said first and second capacitance portions being arranged to be interrelated such that the sum of the two variable capacitances remains constant in order to maintain the frequency of the series resonance, said first and second variable capacitances being also arranged for oppositely-directed variations and the equalizing characteristic of the equalizer is thus varied by adjusting the sharpness of resonance of the series resonant circuit.
Claim 19
Dependent Claim
20 words
The arrangement according to claim 14 wherein said second capacitance portion replaces said main capacitance of the series resonant circuit.
Claim 20
Dependent Claim
23 words
The arrangement according to claim 15 wherein a differential trimmer is provided for effecting the oppositely-directed variations of said two variable capacitance portions.
Claim 21
Dependent Claim
73 words
The arrangement according to claim 14 wherein said first capacitance includes a fixed capacitance coupled in parallel to said main inductance and a variable capacitance coupled in parallel to said fixed capacitance and to said main inductance, and wherein said second capacitance portion is a variable capacitance, predeterminably variable relative to said variable capacitance in parallel with said main inductance, and coupled in parallel to said main capacitance of said series resonant circuit.
Claim 22
Dependent Claim
60 words
The arrangement according to claim 4 wherein the equalizer circuit is a quasi-constant-Z equalizer of T configuration having a series resonant circuit bypassing the parallel branch portion of the configuration, and a parallel-resonant circuit in the series branch portion of the configuration, and wherein the parallel-resonant circuit is kept invariable, with the bypassing series resonant circuit arrangement being variable only.
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |