PURPOSE: To drive a light emitting diode with high voltage drop without increasing the source voltage of a photoelectric switch by operating a light emitting diode driving circuit and a switching circuit simultaneously by a pulse generation circuit.

CONSTITUTION: Such configuration is employed that a capacitor 92 and a charging circuit 91 are connected in series between the switching circuit 8 driven by the pulse generation circuit 1 and a circuit power source, and the output voltage of the switching circuit 8 and the charging voltage of the capacitor 92 can be fed to the light emitting diode LED driving circuit 3 when the switching circuit 8 is turned on. In other words, the LED driving circuit 3 and the switching circuit 8 are comprised so as to be operated simultaneously by the pulse generation circuit 1. Thereby, it follows that the voltage about twice as high as the circuit voltage is applied to the LED driving circuit 3, and even a LED element with high voltage drop such as a red LED and a green LED, etc., can be driven by the circuit voltage, and the voltage drop when the photoelectric switch is turned on using the LED in a flooding circuit can be reduced, therefore, the circuit can be operated by a low source voltage.