Patent ID: 9131555
Filing Date: 2015-09-08
Classification: H05B,Y02B

Abstract:
1. A lighting device that is connected to a DC power source and supplies an electric current to a solid-state light-emitting element whose forward voltage ranges from Vfmin to Vfmax, the lighting device comprising: a DC/DC converter; and a control unit, wherein the DC/DC converter includes: the control unit includes a comparator that compares the current detection value with an electric current reference value, is configured to (i) switch the switching element from the ON state to an OFF state when the control unit senses that the current detection value reaches the electric current reference value based on an output signal from the comparator, and (ii) switch the switching element from the OFF state to the ON state in fixed cycles, each of which being a period where timing at which the inductor finishes releasing the electric current and timing at which the switching element is switched from the OFF state to the ON state coincide with each other when the forward voltage of the solid-state light-emitting element connected to the lighting device is the Vfmax.