does anyone know how automatic doors work its my homework i need help?
There are many types of automatic doors (roll up, sliding, swinging). All have a signal input that, once activated, sends a signal to a control unit that will actuate the motor. The motor then turns how ever fast the control unit has been adjusted to make it turn. The motor will slow down when it either hits a limit switch (a mechanical switch that tells the control that it has been activated) or when the control tells the motor to slow or stop because it has a revolution counter (a counter on the motor that communicates how many turns the motor has made so the control can know where the door is) and it communicates with the control. This is commonly known as a micro processed system and it is what prevents a motor from making a door slam open or closed. There can be many ways to activate an automatic door (key switch, handicap push button, sensor, a reception desk type switch, or even a timer) There are also several different types of sensors, safety sensors, activation sensors, and inside of those two categories there are many more. Hope this helps :)
Automatic doors use a very simple form of radar to detect when someone passes near the door. The box above the door sends out a burst of microwave radio energy and waits for the reflected energy to bounce back. When a person moves into the field of microwave energy, it changes the amount of reflected energy or the time it takes for the reflection to arrive, and the box opens the door.
it works when..when u step infront of it and it will open...it is powered with electricity and force..
Infrared motion detectors see you walk to the door, and send a signal to a computer which open the doors and keep them open until no motion is detected.
