Patent ID: 9161401
Filing Date: 2015-10-13
Classification: H05B,Y02B

Abstract:
1. A lighting circuit, comprising: a plurality of series-connected light-emitting diodes, wherein the series-connected light-emitting diodes are coupled between an input voltage source and an input voltage return associated with the input voltage source; a switching power converter having a magnetic storage element and a switching element for controlling a current supplied through the plurality of series-connected light-emitting diodes; a control circuit for controlling the switching element of the switching power converter, wherein a power supply input of the control circuit is provided by a power supply voltage generated from a terminal of the plurality of series-connected light-emitting diodes having a voltage substantially less than a voltage of the input voltage source; a switching circuit coupled in series with the plurality of series-connected light-emitting diodes and the input voltage source, wherein the switching circuit alternatively couples the terminal of the plurality of series-connected light-emitting diodes to the input voltage return in a first switching state and to the power supply input of the control circuit in a second switching state; and a second plurality of series-connected light-emitting diodes coupled between the switching circuit and the input voltage return, wherein the switching circuit alternatively supplies current to the second plurality of series-connected light-emitting diodes and to the power supply input.