Estimated remaining lamp life indicator system
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsRobert V. Belenger, Gennaro R. Lopriore
Life of this patent
Estimating the term…
Abstract
The present invention relates to a system and method for estimating the remaining life of a light bulb. The system broadly comprises a device for determining a physical condition of the light bulb while the light bulb is in a non-operating mode, a comparison device for comparing the determined physical condition of the light bulb to a reference physical condition for a light bulb of the same type near an end of its life, and a device for displaying an indication of a life expectancy for the light bulb. The system may be integrated into a vehicle or may be portable.
Claims21
A system for indicating an estimated remaining life for a light bulb comprising:
- means for determining a physical condition of said light bulb while said light bulb is in a non-operating mode;
- means for comparing the physical condition of said light bulb to a reference physical condition of a light bulb near an end of its life;
- and
- means for displaying an indication of a life expectancy for said light bulb.
A circuit for determining the remaining life of at least one light bulb comprising:
- a source of electrical power;
- an ohmmeter for measuring cold filament resistance of said at least one light bulb;
- a difference circuit for comparing the measured cold filament resistance of each said light bulb to a reference near end of life filament resistance and for outputting at least one difference signal;
- and
- a life expectancy indicator for receiving said at least one difference signal and for displaying the remaining life for each said light bulb.
A method for estimating the remaining life of a light bulb comprising:
- determining a cold filament resistance for a light bulb being tested;
- and
- comparing said determined cold filament resistance to a reference near end of life filament resistance and outputting a difference signal representative of the remaining life expectancy of said light bulb.
Dependencies are inferred from the claim text.