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:
Mar. 16, 1993
Filed:
Jul. 19, 1991
Robert H Richardson, Hayesville, NC (US);
Lee R Webster, Indialantic, FL (US);
Other;
Abstract
The level of brightness of rapid-start fluorescent lighting is modulated over a range from full brightness at 100% lamp power consumption to minimum brightness at near 0% lamp power consumption. Fluorescent lamp brightness is modulated by controlling the amount of time during cycles of voltage application, such as 60 hz, when current flows through the lamp. An input signal voltage in a given range, for example, from 0 to 5 volts dc, is processed to provide an output which controls the duration of current flow. A cut-off circuit prevents any line voltage from being applied to the lamp at chosen values of input voltage. The cut-off circuit contains hysteresis elements which prevents the lamp from fluttering between off and on states. Modules connected to the lamp's heater elements maintain proper heater element voltage to ensure operation of the lamp form 0% to 100% brightness.