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:
Jun. 26, 2012
Filed:
Sep. 04, 2009
Neil Orchowski, Philadelphia, PA (US);
Neil Orchowski, Philadelphia, PA (US);
Lutron Electronics Co., Inc., Coopersburg, PA (US);
Abstract
A load control device comprises a bidirectional semiconductor switch for controlling the amount of power delivered to an electrical load, and the bidirectional semiconductor switch further comprises two field effect transistors (FETs) in anti-series electrical connection. In the event that one of the FETs fails in a shorted state, and if the load control device is using a phase control dimming technique to control the load, the load control device may provide an asymmetric waveform to the electrical load. In order to determine whether this asymmetric waveform is present, a microprocessor of the load control device use voltage thresholds and/or offsets to monitor the voltage across the FETs. Thus, the microprocessor is operable to detect a fault condition of the load control device wherein the fault condition may comprise an asymmetry condition, or more particularly, a failure condition of one of the FETs.