SAN ANGELO, TX — A San Angelo manufacturer won a patent infringement lawsuit for one of its key products. Principal Lighting Group, known also as Principal LED, located in the San Angelo Business and Industrial Park at 3940 Venture Dr., patented an adaptor that allows commercial business signs to be easily converted from traditional fluorescent lighting to more efficient LED lighting diodes. It is marketed by Principal as the Stik series and is an important revenue generator for the company.