How does a reed switch operate?

A reed switch operates by opening and closing in response to the presence of a magnetic field. It consists of two ferromagnetic blades that are sealed within a glass envelope. When no magnetic field is present, the reed blades remain separated. However, when a magnet approaches the switch, the magnetic field causes the blades to come together, completing the circuit and allowing current to flow. This function makes reed switches particularly useful in various applications, including security systems and sensors, where magnetic activation is desired. By reacting to changes in the magnetic field, the reed switch provides a reliable means of control or signal transmission in electrical circuits.