Ok, so you know at a grocery store how when you walk close to the door, it opens? Does a computer power them? Exactly how do they work? Thanks
prefect example stanley doors one of the manufacture of automatic doors, the automatic doors work off motion the same process as motion sensors lights on the side of a house in this case two sensors are mounted on both sides of the door at the top some look like a oval shape mount on the door once someone walks in front of the door the sensor detects their movement sends a signal through the circuit card to the motor to open the door the same process when someone exits, these doors are now replacing the old photoelectric eye beam that are mounted lower is still being use ,i'm not stating that some on the market is control by a pc but the basic doors that you see at walmart ,krogers,targets,etc are now days control by motion
There is a laser beam, when you break the laser beam!! BAM!! the dorr opens!! their is a mini computer in a sence tho, you could just use google
They have infrared sensors in them. Your body emits infrared radiation. Basically they measure the level of infrared radiation and when it changes significantly they trigger the door to open.
