The working principle of the reed switch is very simple. The magnetizable reeds overlapped at two ends and sealed in a glass tube. The distance between the two reeds is only about several micrometers. The glass tube is filled with high-purity inert gas. When not in operation, the two reeds are not in contact and the applied magnetic field produces different polarities near the end positions of the two reeds. As a result, two reeds of different polarities will attract and close each other. According to this technology, a very small size of the switching assembly can be made, and the switching speed is very fast and has very excellent reliability. The orientation and direction of the permanent magnet determine when and how many times the switch opens and closes.