The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 13, 1993
Filed:
Mar. 26, 1991
James C Johnson, Conyers, GA (US);
National Service Industries, Inc., Atlanta, GA (US);
Abstract
An emergency lighting system operable on line voltage under normal conditions and on battery power upon failure of line voltage, the system comprises a battery, a battery charging circuit, a line monitor, a lamp/ballast interface and a switching transistor inverter circuit in addition to an electric discharge lamp, ballast and conventional associated circuitry as well as mechanical packaging and connections to line voltage. Advantages in installation and operation of the present emergency lighting system occurs through use of the switching transistor inverter circuit which starts and operates the discharge lamp from the battery on line voltage failure. The emergency lighting system of the invention is rapidly installable through wiring of an associated lighting fixture to the system using power input leads to conventional ballast, thereby substantially simplifying installation of the inverter circuit.