Patent US3800136A successfully refreshed from Google Patents.
US3800136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable intensity battery operated light
Assignee: Individual
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Filing: 1972-09-28
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Granted: 1974-03-26
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Expires: 1992-09-28
Abstract
Abstract An adjustable light intensity circuit is provided for use with a flashlight, a car or boat light, or any other device or vehicle employing a battery operated light.
Inventors
- 👤 A Edelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:35
CPC Classifications
F; F21; F21V; F21V23/00; F21L; F21L4/00; F21L4/005; F21S; F21S9/00; F21S9/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
133 words
A portable flashlight comprising a casing having a battery therein, and a light bulb supported by the casing and in series with the battery, and semi-conductor impedance means variable from a low impedance to a high impedance for controlling the amount of current flowing through said light bulb in order to control the brightness thereof carried by said casing, said semiconductor impedance means consisting of a transistor having an emitter and collector in series with said battery and said light bulb, a variable resistance potentiometer having the ends thereof connected to said battery and having a movable center tap, and means connecting said center tap to the base of said transistor, whereby to vary the current flowing from said battery through said light bulb in a range from substantially zero to a maximum.
Claim 2
Dependent Claim
133 words
A portable flashlight comprising a casing having a battery therein, and a light bulb supported by the casing and in series with the battery, and semi-conductor impedance means variable from a low impedance to a high impedance for controlling the amount of current flowing through said light bulb in order to control the brightness thereof carried by said casing, said semiconductor impedance means consisting of a transistor having an emitter and collector in series with said battery and said light bulb, a variable resistance potentiometer having the ends thereof connected to said battery and having a movable center tap, and means connecting said center tap to the base of said transistor, whereby to vary the current flowing from said battery through said light bulb in a range from substantially zero to a maximum.
References Cited (Backward Citations)
US3201580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |