Patent ID: 7081708
Filing Date: 2006-07-25
Classification: H05B

Abstract:
1. A lighting circuit for lighting a vehicular lamp comprising a plurality of light source blocks respectively comprising a plurality of light-emitting diodes connected in series, comprising: a selection unit operable to select at least one of the plurality of light source blocks, thereby selecting a number of light-emitting diodes to be connected in said vehicular lamp based on an external instruction; a switch operable not to flow a current through at least one of the light source blocks not selected according to the selection of said selection unit; a switching regulator operable to apply an output voltage based on a power-supply voltage output by an external DC power supply to said selected number of light-emitting diodes, to supply a supply current to said selected number of light-emitting diodes; and an output controlling unit operable to control said output voltage of said switching regulator based on said supply current, wherein