hi,
the simplest door sensor is a couple of magnet and a sensor switch that is closed when the magnet is near to switch and open when it is far...attache the magent to your door and the switch on wall near to door, when the door open the switch is opened...its reliable, no connection between door and any circuit and also cheap.
why not use some light sensors like LED+LDR
or IR LED+photo diode or some 38K IR+TSOP. They are cheaply available and easy to implement compared with other sensors
I think the original poster was asking about lift/elevator door. As I know the elevator door has some sensor mechanism to eliminate accident by closing the door when there is an object in between the door.
Perhaps following website could be used as reference:
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The sensor mechanism also found on the subway train door.
hi,
i m still in dark with door sensor.
i am working with IR.
Problem is—
-I am not getting the response i want,
-Receiver does not respond to emitter, it works fine with any tv/cd remote.
But not with emitter. I tried and burnt several emitters.
If you use IR TV receiver (like TSOP) then you must modulate the signal transmitted with 38KHz. Read the documentation from following link and the pdf file from receiver circuit.
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