Passage Detector
A passage detector is used to indicate that a person is walking through a door or entering a room.
use
The most common area of application is in stores where the entrance is not in front of the seller for the entire opening time. Informed by the signal noise, the salesperson can then go to the customer so that he does not feel left alone or can steal something unnoticed.
to form
In the electrical version, the sensors can be taken over by a light barrier , a motion detector or a door contact ( electrical contact attached to the door in such a way that it is actuated when the door is opened). This triggers a signal (e.g. electronic gong or bell ).
It is also possible to signal purely mechanically: The movement of the door is used to generate a noise. For example, a bell can be fastened over the door, which is struck by a lever that is pulled off the door when it is opened. Tubular bells serve a similar purpose . The purely mechanical variants have the advantage that they also work without electricity, but sometimes the noise can be avoided with a little skill by slowly and carefully opening the door, so that there is not necessarily security against unauthorized entry.
Sounds
Mechanical designs mostly use bells as sounders. With the electrical variant, the type of signal is varied.
See also
Web links
- Door bell with photosensor (accessed on February 12, 2016)