Abstract: The present invention relates to a photoelectric switch which has a light projecting means that projects light pulses as a result of a pulse signal and a light receiving means that receives the light pulses and outputs a light receiving signal. In one arrangement an enhanced voltage of about two times the supply voltage is applied to a light projecting element, such as an LED, thereby making it possible to provide a photoelectric switch which operates at a reduced power supply voltage. By providing a composite LED drive voltage the drop in supply voltage, inherent in conventional photoelectric switches when the output circuit is activated (thereby reducing the voltage to the light emitting element) does not inhibit operation.