A control device includes a plurality of LED arrays connected to a ground and connected in parallel to one another, each of the plurality of LED arrays including one or more LEDs connected in series and a resistance element connected in series to the LEDs, a first switching circuit disposed between each of the plurality of LED arrays and a power source, a second switching circuit disposed between each of the plurality of LED arrays and the power source, a capacitor having one end connected to the first switching circuit and another end connected to the plurality of LED arrays, a voltage detection circuit having an end connected to the other end of the capacitor, and a control circuit that controls switching of conduction states of each of the first and second switching circuits, and reads a voltage from the voltage detection circuit.