POWER SOURCE DEVICE AND LIGHT RADIATION SYSTEM EQUIPPED WITH SAME

The present invention intends to increase a number of a type of a light source 12 that can be determined by widening a range of the resistance value of a resistance that can be used as an identification resistance 13. The power source device 20 is to be connected to a light radiation device 10 which is equipped with: a light source 12 having one or a plurality of LEDs 11; and an identification resistance 13 whereof the resistance value differs for each type of the light source 12. The power source device 20 comprises: an identification resistance determination circuit 23 having a voltage dividing resistance 231 to be connected in series to the identification resistance 13; and a control unit 24 for measuring the divided voltage applied to the voltage dividing resistance 231, determining the type of the light source 12 based on the divided voltage value, and controlling the power to the light source 12 according to the type thereof. The identification resistance determination circuit 23 has a configuration in which a plurality of voltage dividing resistances 231 are provided, each having a different resistance value from one another, and the voltage dividing resistance 231 to be connected to the identification resistance 13 can be switched 231.