Photoelectric switch

Abstract

Abstract PURPOSE: To prevent erroneous operation by changing the pulse lighting period of a light emitting element when noisy light is incident. CONSTITUTION: A control circuit composed of TR13 and resistances 11 and 12 is connected to a CR oscillator composed of resistances 14 and 16 to 19, a capacitor 15, diodes 20 and 22, and a comparator 21. The output from a pulse oscillator makes LED27 emit through an amplifier composed of resistances 23 and 24 and TR25. The phototransistor 29 of a light receiving part IR receives the emitted light and the output from the phototransistor 29 is waveformed and digitally integrated through FF36 to 40, an OR gate 41 and an AND gate 42 to enter FF composed of NAND gates 43 and 44, an NOR gate 46 and an NOT circuit 45. When 5 pulses are inputted to FF36 to 40 successively, a signal is outputted from a point G. When stray light is entered in the phototransistor and overlapped with a pulse signal, TR15 is turned off and the output from the point G is stopped because the pulse is delayed, preventing erroneous operation. COPYRIGHT: (C)1982,JPO&Japio

Inventors

• 👤 Toshibumi Fukuyama
• 👤 Norio Onchi

Bibliographic Details