POWER SOURCE DEVICE AND LIGHT RADIATION SYSTEM EQUIPPED WITH SAME

The present invention intends to increase the type of a light source that can be determined by widening a range of an identification resistance value. The power source device is connected to a light radiation device which is equipped with: a light source having one or a more LEDs; and an identification resistance whereof the resistance value differs for each type of the light source. The power source device comprises: an identification resistance determination circuit having a voltage dividing resistance connected in series to the identification resistance; and a control unit for measuring the divided voltage applied to the voltage dividing resistance, determining the type of the light source based on the divided voltage value, and controlling the power to the light source according to the type thereof. The identification resistance determination circuit has a plurality of switchable voltage dividing resistances are provided, each having a different resistance value.