Communications: electrical – Condition responsive indicating system – Specific condition
Patent
1994-08-12
1996-12-03
Hofsass, Jeffery
Communications: electrical
Condition responsive indicating system
Specific condition
340628, 340629, 356339, 250573, 250574, G08B 1710
Patent
active
055812414
ABSTRACT:
A smoke detector that operates on the principle of scattered light is disclosed that has the capability of an operating sensitivity that is tens of times greater than that of smoke detectors presently available. Plural light sources are used, their light rays directed radially toward the center of a cylindrical detector chamber having a mirrored wall that reflects light back toward the chamber's center, thereby to brightly illuminate a central detection zone. Scattered light from smoke in this zone is detectable by a photocell at right angles to the converging multiple light rays. To obtain highly improved stability of the light output that enables ultra-high sensitivity, the light sources are light-emitting diodes in series connection and they are driven by a very stable constant voltage source that also powers the photocell detector. This system gains impressive sensitivity while reducing nuisance alarms that have been a common problem regarding efforts to increase smoke detector sensitivity. Whereas the goal of this invention is to improve the public safety, improvements are presented in smoke collection also, whereby ambient air is quickly and efficiently brought to the detector cell itself using convection currents that are enhanced by the aerodynamic design of the housing surrounding the cell.
REFERENCES:
patent: 3799670 (1974-03-01), Kohr
patent: 3914616 (1975-10-01), Mooibroek
patent: 4025915 (1977-05-01), Enemark
patent: 4121110 (1978-10-01), Solomon
patent: 4181439 (1980-01-01), Tresch et al.
patent: 4221485 (1980-09-01), Schulze
patent: 4469953 (1984-09-01), Fujisawa et al.
patent: 4678921 (1987-07-01), Nakamura et al.
patent: 4754150 (1988-06-01), Orioka et al.
patent: 4758733 (1988-07-01), Mochizuki
patent: 4769550 (1988-09-01), Dolnick
patent: 4857895 (1989-08-01), Kaprelian
patent: 4906978 (1990-03-01), Best et al.
patent: 5008559 (1991-04-01), Beyersdorf
patent: 5381130 (1995-01-01), Thuillard et al.
Jonathan Dahl, Disney Could Jump on This Idea By Offering a Jimminy Cricket Line, The Wall Street Journal, Thursday, Aug. 12, 1993.
Kaufman Michael
Thomas Richard W.
Bergquist Donald A.
Hofsass Jeffery
Mannava Ashok
Voice Products Inc.
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