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:
Jan. 14, 2003
Filed:
Sep. 25, 2001
Robert Alexander Erhardt, Schaumburg, IL (US);
Steven Pilgrim, Waukegan, IL (US);
Raymond Kulka, Chicago, IL (US);
Ching-Yao Hung, Palatine, IL (US);
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
Control circuitry for controlling the output power of an electronic ballast system having a power supply branch circuit having power lines comprising a line voltage line and a common line, and a ballast stage having (i) inputs connected to the power lines for providing power to the lamp, (ii) internal power control feedback circuitry that defines a feedback loop for controlling the amount of power applied to the lamp, and (iii) a control signal input for receiving a control signal that affects operation the internal power control feedback circuitry and the level of power outputted by the ballast stage. The control circuitry comprises a first circuit having an input for connection to one of the power lines. The first circuit generates a control signal for input into the control input of the ballast stage. The control circuitry having a first predetermined magnitude when one of the power lines is connected to the input of the first circuit and a second predetermined magnitude when the power lines are isolated from the input of the first circuit. The control circuitry further comprises a second circuit having a first state for reducing the first and second predetermined magnitudes of the control signal by a predetermined increment so as to effect step dimming of the lamp and a second state that maintains the first and second predetermined magnitudes of the control signal.