Light emitting diode retrofit lamp
AssigneeNational Service Industries, Inc.
InventorJames C. Johnson
Life of this patent
Estimating the term…
Abstract
A retrofittable lamp using light emitting diodes as the illumination source, the lamp is fitted with any one of the common lamp bases and is intended as a retrofit for incandescent lamps having such bases in illuminated signs such as exit signs and the like. The invention contemplates the packaging of a number of light emitting diodes in a circuit usually having a current limiting device to allow LED operation at a desired current level. The light emitting diodes are placed within a standard glass or plastic bulb envelope in arrangements capable of providing even illumination from the lamp.
Claims8
A lamp capable of operation on standard line voltages and particularly useful as a replacement lamp in an emergency exit sign and the like, comprising:
- a plurality of light emitting diodes arranged in series and comprising a circuit locatable within the spatial confines of the lamp;
- means disposed in the circuit for limiting current through the light emitting diodes, said means comprising a capacitor acting as the only effective limiting impedance in the circuit;
- and,
- a diode bridge disposed in the circuit between the light emitting diodes and the capacitor.
A lamp capable of operation on standard line voltages and particularly useful as a replacement lamp in an emergency exit sign and the like, which exit sign is provided with at least one socket intended to receive a base of an exit sign lamp which is replaced by the present lamp, the present lamp having a base which can be received into the socket, comprising:
- a plurality of light emitting diodes arranged in series and comprising a circuit locatable within the spatial confines of the lamp;
- means disposed in the circuit for limiting current through the light emitting diodes, said means comprising a capacitor acting as the only effective limiting impedance in the circuit;
- and,
- means for rectifying current disposed in the circuit between the light emitting diodes and the capacitor.
A lamp capable of operation on standard line voltages and particularly useful as a replacement lamp in an emergency sign and the like, comprising:
- a plurality of light emitting diodes arranged in series and comprising a circuit locatable within the spatial confines of the lamp;
- a single circuit element arranged in the circuit for limiting current through the light emitting diodes, the single circuit element comprising the only effective limiting impedance in the circuit and comprising a capacitor;
- and,
- a diode bridge disposed within the circuit between the light emitting diodes and the single circuit element.
A lamp capable of operation on standard line voltages and particularly useful as a replacement lamp in an emergency sign and the like, comprising:
- a plurality of light emitting diodes arranged in series and comprising a circuit locatable wtihin the spatial confines of the lamp;
- a single circuit element arranged in the circuit for limiting current through the light emitting diodes, the single circuit element comprising the only effective limiting impedance in the circuit;
- and,
- a diode bridge disposed within the circuit between the light emitting diodes and the single circuit element, the single circuit element comprising a capacitor.
Dependencies are inferred from the claim text.