Home security door sensors operation principle

The door sensor system is a safety alarm system. If the home security door sensors not noticed, the door sensor will not be easy to see. The so-called home security door sensors is actually a door sensor switch consisting of two parts: the smaller part is a permanent magnet that is used to generate a constant magnetic field. The larger is the door magnet body, which has a normally open type inside. 

 
When the permanent magnet and the reed are close to each other (less than 5 mm), the door magnetic sensor is in a waiting state. When the permanent magnet leaves the reed for a certain distance, it is always open.

The magnet and the reed switch are respectively installed in the door frame (window frame) and the door leaf (window leaf), and are basically embedded (also surface-mounted), so people in the industry are generally not aware of these. 

Open the split door and the outer window, look at the top of the split door door frame and the window frame of the outer window, and you can see the round and generally white components. In fact, this is the so-called door magnet,we also called home security door sensors.