Reedschakeling

Reedschakeling, also known as reed switching, is a form of electromechanical switching that utilizes a hermetically sealed glass tube containing two ferromagnetic contacts. These contacts are typically in the form of flat reeds, which are springy metallic strips. When a magnetic field is brought near the glass tube, the reeds become magnetized and attract each other, causing them to bend and make electrical contact. When the magnetic field is removed, the inherent springiness of the reeds causes them to return to their original position, breaking the contact.

This design offers several advantages. The sealed nature of the glass tube protects the contacts from environmental factors such as dust, moisture, and corrosive gases, leading to a long operational life and high reliability. The absence of exposed moving parts also makes them suitable for use in hazardous or explosive environments. Reed switches are often used as sensors. For example, they can be incorporated into security systems to detect the opening of doors or windows, as their activation can be triggered by a magnet attached to the moving object. They are also employed in level sensors, where a float with a magnet rises or falls with a liquid, actuating a reed switch at a specific level.

The actuating magnetic field can be generated by a permanent magnet, an electromagnet, or even by the magnetic field produced by current-carrying conductors. The sensitivity of a reed switch is determined by the magnetic field strength required to close the contacts. Different types of reed switches are available, varying in size, contact rating (the maximum voltage and current they can switch), and sensitivity. Applications range from simple on/off switching in consumer electronics to more complex industrial automation tasks.