Patent US4225843A successfully refreshed from Google Patents.
US4225843A
Expired / Lapsed
US
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Variable attenuator
Assignee: Alps Alpine Co Ltd
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Filing: 1978-06-29
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Granted: 1980-09-30
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Expires: 1998-06-29
Abstract
Abstract A variable attenuator comprises a generally horseshoe-shaped main resistance element, a sliding member movable thereover, and a bypass provided around that portion of the main resistance element adjacent the end portion of the path of said sliding member. The bypass is made of a conductive element or conductive element and a resistance element, the amount of current flowing through said bypass being thereby increased to enable a maximum attenuation.
Inventors
- 👤 Moritoshi Nakamura
- 👤 Ichiro Mutoh
- 👤 Tetsuhiro Kiyono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:40
CPC Classifications
H; H01; H01C; H01C10/00; H01C10/30; H01C10/32
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
133 words
A variable attenuator including a resistance element, first and second conductive members each electrically connected to a respective end portion of said resistance element and having respective first and second terminals connected thereto, a sliding member slidingly movable along said resistance element between a first position on said first conductive member and a second position on said second conductive member, and means associated with said first conductive member for reducing the voltage drop between said sliding member and said first terminal when said sliding member is in said first position, said reducing means including a conductive bypass for electric current extending from said first conductive member to a part of said resistance element spaced therefrom to provide a path shunting current away from the current path including said sliding member and first terminal.
Claim 2
Dependent Claim
133 words
A variable attenuator including a resistance element, first and second conductive members each electrically connected to a respective end portion of said resistance element and having respective first and second terminals connected thereto, a sliding member slidingly movable along said resistance element between a first position on said first conductive member and a second position on said second conductive member, and means associated with said first conductive member for reducing the voltage drop between said sliding member and said first terminal when said sliding member is in said first position, said reducing means including a conductive bypass for electric current extending from said first conductive member to a part of said resistance element spaced therefrom to provide a path shunting current away from the current path including said sliding member and first terminal.
Claim 3
Dependent Claim
43 words
A variable attenuator according to claim 1, wherein said bypass consists of a leg portion extending along the upper surface of said resistance element and outside the path of said sliding member, and an arm portion crossing the path of said sliding member.
Claim 4
Dependent Claim
18 words
A variable attenuator according to claims 1 or 2, wherein said bypass is made of a silver paste.
Claim 5
Dependent Claim
49 words
A variable attenuator according to claim 1, wherein said bypass consists of a conductive strip crossing the path of said sliding member, a conductive part extending from said first conductive member, and a resistance portion having a low resistance and extending from said conductive strip to said conductive part.
Claim 6
Dependent Claim
26 words
A variable attenuator according to claim 4, wherein said first and second conductive members, said conductive strip and said conductive part, are made of silver paste.
Claim 7
Dependent Claim
30 words
A variable attenuator according to claim 1, wherein said bypass consists of a single portion which is extended outside the path of said sliding member from said first conductive member.
Claim 8
Dependent Claim
15 words
A variable attenuator according to claim 6, wherein said bypass is made of silver paste.
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) | 1983-09-30 | 1984-03-31 | 1984-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-30 | 1988-03-31 | 1988-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-30 | 1992-03-31 | 1992-09-30 | $7700.00 | Window Closed / Lapsed |