Patent US3869641A successfully refreshed from Google Patents.
US3869641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
AC Responsive led pilot light circuitry
Assignee: Monsanto Co
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Filing: 1973-10-24
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Granted: 1975-03-04
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Expires: 1993-10-24
Abstract
Abstract Disclosed is light-emitting electronic circuitry including a pair oppositely poled, parallel connected diodes, at least one of which is a light-emitting diode (LED); these diodes are serially connected to a capacitor between a pair of circuit AC input terminals. The capacitor provides the necessary AC voltage drop in series with these diodes when the circuitry is connected to a source of AC line voltage, and the minimum power and heat dissipated in this circuit make it especially well suited for small package pilot light applications.
Inventors
- 👤 Jack Goldberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:45
CPC Classifications
H; H05; H05B; H05B45/00; H05B45/40; H05B45/42
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
154 words
An LED pilot light operable from a source of AC line voltage, comprising a pair of light-emitting diodes, said diodes being connected in parallel with opposite polarity, each of said diodes generating light when properly forward biased, an enclosure having a light transmissive portion, means for supporting both of said diodes in said enclosure such that light emitted by said diodes radiates from said enclosure through said light transmissive portion in a single direction, and a capacitor having one side interconnected with said pair of diodes at one junction common to said diodes, a first circuit input terminal interconnected with the other side of said capacitor, a second circuit input terminal interconnected with the other junction common to said diodes, the capacitor voltage following AC line voltage applied to said input terminals and limiting the voltage drop across said diodes as said diodes alternately conduct on respective half cycles of said AC line voltage.
Claim 2
Dependent Claim
154 words
An LED pilot light operable from a source of AC line voltage, comprising a pair of light-emitting diodes, said diodes being connected in parallel with opposite polarity, each of said diodes generating light when properly forward biased, an enclosure having a light transmissive portion, means for supporting both of said diodes in said enclosure such that light emitted by said diodes radiates from said enclosure through said light transmissive portion in a single direction, and a capacitor having one side interconnected with said pair of diodes at one junction common to said diodes, a first circuit input terminal interconnected with the other side of said capacitor, a second circuit input terminal interconnected with the other junction common to said diodes, the capacitor voltage following AC line voltage applied to said input terminals and limiting the voltage drop across said diodes as said diodes alternately conduct on respective half cycles of said AC line voltage.
Claim 3
Dependent Claim
35 words
An LED pilot light as set forth in claim 1 wherein said capacitor is mounted within said enclosure, whereby said pilot light is entirely self-contained for direct interconnection with said source of AC line voltage.
Claim 4
Dependent Claim
33 words
An LED pilot light as set forth in claim 1 wherein said enclosure is tubular and includes a lens across one end thereof, said diodes being adapted to emit radiation through said lens.
Claim 5
Dependent Claim
68 words
An LED pilot light as set forth in claim 2 wherein said enclosure and capacitor are each cylindrical and the longitudinal axes of said enclosure and capacitor extend generally in the same direction, said diodes being supported with said enclosure at one end thereof with respect to the longitudinal axis of said enclosure, and said first and second input terminals being at the other end of said enclosure.
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) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |