Photoelectric switches have been used for level detection, level control, product counting, width discrimination, speed detection, fixed length shearing, hole identification, signal delay, automatic door sensing, color mark detection, punching and shearing, and Security protection and many other areas. In addition, the use of infrared concealment can also be used as a burglar alarm in banks, warehouses, shops, offices and other places where it is needed.
The commonly used infrared photoelectric switch uses the principle of reflection of the near-infrared beam by the object, and the presence or absence of the object is detected by the intensity of the reflected light reflected by the synchronous loop. The photoelectric sensor first emits an infrared beam to reach or transmit. The object or mirror is reflected by the infrared beam, and the photoelectric sensor receives the reflected beam, and judges the existence of the object according to the strength of the beam. There are many types of infrared photoelectric switches, generally there are several main types of mirror-reflective photoelectric switches, diffuse reflection, trough, through-beam, and fiber-optic. Photoelectric switch quick and easy automatic selection has been included.
Different photoelectric switches are used in different occasions. For example, optical-type photoelectric switches are often used on electromagnetic vibrating feeders. Diffuse reflective photoelectric switches are often used in the supply of intermittent packaging machine packaging films, in continuous high-speed packaging machines. Trough photoelectric switches are often used.
An optocoupler is an electric-optical-electrical conversion device that transmits electrical signals by means of light. It consists of two parts: a light source and a light receiver. The light source and the light receiver are assembled in the same sealed casing and separated from each other by a transparent insulator. The pin of the light source is the input end, and the pin of the light receiver is the output end. The common light source is the light emitting diode, and the light receiver is a photodiode, a phototransistor and the like. There are many types of photocouplers, such as photodiode type, phototransistor type, photoresistor type, light control thyristor type, photoelectric Darlington type, integrated circuit type, etc. Working principle: The electric signal is applied to the input end of the optocoupler to make the illumination source emit light. The intensity of the light depends on the magnitude of the excitation current. After the light is irradiated onto the light-receivers packaged together, the photocurrent is generated due to the photoelectric effect. The output of the device is taken out, so that the conversion of electricity, light and electricity is realized.