Apparatus, method and system for providing AC line power to lighting devices

摘要

An apparatus, method, and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (LEDs). A representative apparatus comprises: a plurality of LEDs coupled in series to form a first plurality of segments of LEDs; a plurality of switches coupled to the plurality of segments of LEDs to switch a selected segment into or out of a series LED current path in response to a control signal; a current sensor; and a controller which, in response to a first parameter and during a first part of an AC voltage interval, generates a first control signal to switch a corresponding segment of LEDs into the series LED current path; and during a second part of the AC voltage interval, generates a second control signal to switch the corresponding segment of LEDs out of the first series LED current path.