光电开关（国外英文资料）.docVIP

光电开关（国外英文资料） Basic knowledge of photoelectric sensors and technical terms Sensors, photoelectric sensors, basic knowledge, professional term photoelectric sensor information, instruction, maintenance of engineering control based business to provide you with the most professional sensor information, quotation, specification, maintenance, use common sense 2009-02-23 source: Internet browsing: the 50 photosensor is a small electronic device that can detect changes in the intensity of the light it receives. Early used to detect objects in the presence of photoelectric sensor is a small metal cylindrical equipment, transmitters with a calibrated camera, the light focusing at the receiver, the receiver out of the cable to the device to a vacuum tube amplifier. There is a small incandescent lamp in the metal cylinder as a light source. These small, rugged incandescent sensors are the prototype for todays photoelectric sensors. LED (LED) Leds first appeared in the 1860s, and now we can often see them on electrical and electronic devices as indicators. An LED is a semiconductor device that has the same electrical properties as a normal diode, and is different because it glows when the LED is plugged in. Because the LED is solid, it can extend the life of the sensor. Leds could be made smaller and more reliable than incandescent sensors. Unlike incandescent bulbs, leds resist shocks and dont have filament. In addition, leds emit light that is only part of the light energy produced by the same size. (with the exception of a laser diode, it works the same way as an ordinary LED, but can produce several times as much light energy as possible, and can reach further detection distances). Leds emit infrared light invisible to the human eye and can also emit visible green, yellow, red, blue, blue or white light. Modulated LED sensors In 1970, it was discovered that leds also had a better advantage than life expectancy, which was that it was able to switch at a very fast speed, which