Automatic door openers are extremely helpful in households, as well as commercial buildings. The way they work is actually quite simple. Usually there is a button or controller the door opener is connected to. When the button is pressed, the opener receives a signal to open the door. The mechanism is then in action. The motor is activated and it drives the pulley and belt of the device. Automatic doors also feature sensors. Those allow them to detect if there is a person or object in the way. If there is nothing in the way, the door will close.