Also known as an “infrared sensor,” this type of garage door sensor uses a beam of infrared light to detect if an object is in the way of the door. If the beam of light is broken, the sensor knows that there is something in the way and will not allow the door to close. Most automatic garage doors work using a system of sensors and switches. The sensors are usually located at the botto... https://dailyuploads.net/z9us72piz447/How_Modular_Design_Is_Shaping_the_Future_of_Technologyblesu.pdf