Patent ID: 8669718

Claim:
An LED lighting device comprising: a power source unit for stepping down a DC input voltage to a predetermined DC output voltage and supplying the DC output voltage to a light-emitting diode; a control unit for adjusting the DC output voltage by controlling the power source unit; and a control power source unit for supplying a control power to the control unit, wherein the control power source unit generates the control power based on the DC output voltage from the power source unit, the control power source unit includes: a current-limiting resistor for limiting an electric current that flows from the power source unit to the control unit; a constant voltage unit for converting a voltage to be applied to the control unit through the current-limiting resistor unit to a constant voltage; and a switching unit for switching a resistance value of the current-limiting resistor unit among a plurality of resistance values, and the switching unit switches the resistance value of the current-limiting resistor unit to a smaller resistance value as the DC output voltage decreases.