US3890589A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable resistor
Assignee: NEC Corp
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Filing: 1973-06-20
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Granted: 1975-06-17
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Expires: 1993-06-20
Abstract
Abstract A resistive element has a gradient of resistivity extending along its length. It is held in slidable contact with two or more brushes spaced-apart from each other. The resistance between the brushes can be varied by changing their position relative to the resistive element and the gradient or resistivity. The resistive element may have an arcuate configuration and the relative position may be changed by rotating the element. Two such variable resistors having a logarithmic resistance gradient may be combined in a variable resistance attenuator.
Inventors
- 👤 Masanori Kogo
- 👤 Hisashi Honda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:33
CPC Classifications
H; H01; H01C; H01C10/00; H01C10/26
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
A variable resistance attenuator comprising an input terminal, an output terminal, a common terminal, a first variable resistor connected between said input terminal and said output terminal, first and second resistors connected in series between said input terminal and said output terminal, and a second variable resistor connected to the series connection between said first and second resistors and connected at its opposite terminal to said common terminal, said first and second variable resistors each comprising an electrically resistive element, the incremental resistance of which varies along its length, to form a gradient of resistivity, and two brushes spaced apart by a constant distance in slidable contact with each said resistive element, said gradient being such that the resistance between the brushes varies logarithmically, but the inductance between them remains substantially constant as they are moved with respect to the gradient.
Claim 2
Dependent Claim
141 words
A variable resistance attenuator comprising an input terminal, an output terminal, a common terminal, a first variable resistor connected between said input terminal and said output terminal, first and second resistors connected in series between said input terminal and said output terminal, and a second variable resistor connected to the series connection between said first and second resistors and connected at its opposite terminal to said common terminal, said first and second variable resistors each comprising an electrically resistive element, the incremental resistance of which varies along its length, to form a gradient of resistivity, and two brushes spaced apart by a constant distance in slidable contact with each said resistive element, said gradient being such that the resistance between the brushes varies logarithmically, but the inductance between them remains substantially constant as they are moved with respect to the gradient.
Claim 3
Dependent Claim
67 words
A variable resistor comprising an electrically resistive element the incremental resistance of which varies along its length to form a gradient of resistivity, and two moveable brushes spaced apart by a fixed distance and in slidable contact with the resistive element, the resistive element providing a substantially constant inductance and a linearly variable resistance as the position of the brushes with respect to the gradient is varied.
Claim 4
Dependent Claim
67 words
A variable resistor comprising an electrically resistive element the incremental resistance of which varies along its length to form a gradient of resistivity, and two moveable brushes spaced apart by a fixed distance and in slidable contact with the resistive element, the resistive element providing a substantially constant inductance and a linearly variable resistance as the position of the brushes with respect to the gradient is varied.
Claim 5
Dependent Claim
67 words
A variable resistor comprising an electrically resistive element the incremental resistance of which varies along its length to form a gradient of resistivity, and two moveable brushes spaced apart by a fixed distance and in slidable contact with the resistive element, the resistive element providing a substantially constant inductance and a logarithmically variable resistance as the position of the brushes with respect to the gradient is varied.
Claim 6
Dependent Claim
67 words
A variable resistor comprising an electrically resistive element the incremental resistance of which varies along its length to form a gradient of resistivity, and two moveable brushes spaced apart by a fixed distance and in slidable contact with the resistive element, the resistive element providing a substantially constant inductance and a logarithmically variable resistance as the position of the brushes with respect to the gradient is varied.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |