Editing Door (section)

=== Automatic ===
'''[[Automatic door|Automatically opening doors]]''' are powered open and closed either by electricity, spring, or both. There are several methods by which an automatically opening door is activated:

# A [[sensor]] detects traffic is approaching. Sensors for automatic doors are generally:
#* A [[pressure sensor]] – e.g., a floor mat which reacts to the pressure of someone standing on it.
#* An [[infrared]] [[curtain]] or beam which shines invisible light onto sensors; if someone or something blocks the beam the door is triggered open.
#* A [[motion sensor]] which uses low-power microwave [[radar]] for the same effect.
#* A remote sensor (e.g. based on infrared or radio waves) can be triggered by a portable [[remote control]], or is installed inside a vehicle. These are popular for garage doors.
# A [[switch]] is operated manually, perhaps after security checks. This can be a push button switch or a swipe card.
# The act of pushing or pulling the door triggers the open and close cycle. These are also known as power-assisted doors.

In addition to activation sensors, automatically opening doors are generally fitted with safety sensors. These are usually an infrared curtain or beam, but can be a pressure mat fitted on the swing side of the door. The safety sensor prevents the door from colliding with an object by stopping or slowing its motion. A mechanism in modern automatic doors ensures that the door can open in a power failure.