PURPOSE: To reduce an output voltage at the time of turning on a photoelectric switch and to add hysteresis to switching characteristics when a light beam is cut off or made incident.
CONSTITUTION: A light emitting diode 5, output transistor Q1 and the parallel circuit of a resistor R1 are connected between terminals 1 and 2. A light receiving circuit 6 receives the light of the light emitting diode 5 and when any object is detected, a signal processing circuit 7 outputs a signal at an H level. At such a time, the transistor Q1 for switching is conducted, and a driving current flows to a load 3 connected to a DC power source 4. In this case, the current of the light emitting diode 5 is increased, and the quantity of lights is increased. At the same time, the driving currents of the light receiving circuit 6 and signal processing circuit 7 are increased as well. Therefore, the switching characteristics at the time of ON are stablized, and the adverse influence of noise from the load or power source is reduced.
SHIBATA KUNIHARU
ISHIBASHI KEISUKE
