A screw-in LED lamp which derives its power from a socket connected to an A-C power line, the lamp being screwed into the socket to produce a light of high intensity useful as a traffic signal or as a warning signal. The lamp includes a screw-in plug connected to a regulator in which the A-C is converted...http://www.google.ca/patents/US5850126?utm_source=gb-gplus-sharePatent US5850126 - Screw-in led lamp
