Patent ID: 10136483

Abstract:
An LED lamp, comprising a first full-wave rectifier, a ballast operation circuit, an LED driving circuit, LED array(s), and an optocoupler, replaces a fluorescent tube or a conventional LED tube lamp in lamp fixture sockets that are wired to connect to either AC mains or a ballast. The ballast operation circuit, comprising two frequency sensitive devices, a second full-wave rectifier, and two or more diodes connected in series, auto-selects an input AC voltage to operate the LED lamp without ambiguity and safety issues. When the input AC voltage is from the ballast, the optocoupler is enabled to disable the LED driving circuit, whereas the LED array(s) are powered by the second full-wave rectifier. When the input AC voltage is from the AC mains, the optocoupler is disabled to maneuver the LED driving circuit, whereas the LED array(s) are operated by the LED driving circuit, pre-powered by the first full-wave rectifier.