Patent ID: 8760078
Filing Date: 2014-06-24
Classification: H05B,Y02B

Abstract:
1. A lighting system, comprising: one or more light-emitting devices; an alternating current to direct current (AC-DC) converter having an inductor, a first plurality of switches, a second plurality of switches, and a switch control circuit, said AC-DC converter configured to directly convert AC power from an AC power source to DC power without using a diode bridge rectifier and without using a synchronous bridge rectifier, said DC power used to power said one or more light-emitting devices; and a comparison circuit configured to determine times when the magnitude of an AC input voltage applied to an input of said AC-DC converter is greater than the DC output voltage produced at an output of said AC-DC converter and determine times when the magnitude of said AC input voltage is less than the negative of said DC output voltage, wherein the switch control circuit of said AC-DC converter is configured to turn the switches of said first plurality of switches to repeatedly turn ON and OFF during positive half cycles of said AC input voltage when said comparison circuit determines that the magnitude of said AC input voltage is greater than said DC output voltage and control the switches of said second plurality of switches to repeatedly turn ON and OFF during negative half cycles of said AC input voltage when said comparison circuit determines that the magnitude of said AC input voltage is less than the negative of said DC output voltage.