The working principle and application of photoelectric switch

A photoelectric switch is a sensor that uses a photoelectric element as a detection element. It first converts the measured change into a change in an optical signal, and then further converts the optical signal into an electrical signal with the help of a photoelectric element. The photoelectric switch is generally composed of a light source, an optical path, and a photoelectric element. It consists of three parts. The photoelectric detection method has the advantages of high accuracy, fast response, non-contact, etc., and there are many measurable parameters, the structure of the sensor is simple, and the form is flexible and diverse. Therefore, the photoelectric sensor is widely used in detection and control.

The optical measurement and control system made by the different principle of light flux on the photoelectric element is diverse. According to the output nature of the photoelectric element (optical measurement and control system), it can be divided into two categories, namely, analog photoelectric sensor and pulse (switch) photoelectric Sensor. The analog photoelectric switch converts the measured into a continuously changing photocurrent, which has a single value relationship with the measured. The analog photoelectric sensor can be divided into the transmission (absorption) type according to the method of being measured (detecting the target object), There are three types: diffuse reflection type and shading type (beam blocking). The so-called transmission type means that the measured object is placed in the light path, and the light energy emitted by the constant light source passes through the measured object, and after part of it is absorbed, the transmitted light is projected to On the photoelectric element; the so-called diffuse reflection type means that the light emitted by the constant light source is projected onto the measured object, and then reflected from the surface of the measured object and then projected onto the photoelectric element; the so-called shading type refers to when the light flux emitted by the light source passes through the measured object The light shields a part of it, so that the luminous flux on the projection photoelectric element changes, and the degree of change is related to the position of the measured object in the light path.