Automatic doors pop wide open as you come near. They shut behind you after you walk through. What makes the doors move all by themselves?
Automatic doors may seem simple, but they are not. They are complex machines. They have many parts that work together to open and close the doors safely. Some use a sensor and motor system. The sensor above the door sends out a special light that can tell if something is near the door. When you walk toward the door, that something is you. The sensor sends out a signal that tells a motor to open the doors. A timer keeps the doors open long enough for you to walk into the store.
Suppose you stop to tie your shoelaces in the middle of the doorway. Lucky for you, most doors also have another set of sensors that keep you safe. These sensors are found along the inside edge of the doors. They will “see” you between the door. Then the timer resets until you move through the doorway.
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"How do automatic doors work?" was posted on Wednesday, September 19th, 2007 at 11:54 pm.