reedkontakter

A reed contact, also known as a reed switch, is an electrical switch operated by an applied magnetic field. It consists of two ferrous metal reeds, or contacts, hermetically sealed in a glass tube. The reeds are typically flat and overlap each other. When a magnetic field is brought near the switch, the reeds become magnetized and attract each other, causing them to bend and make electrical contact. When the magnetic field is removed, the elasticity of the reeds causes them to spring back to their original position, breaking the contact.

Reed contacts are commonly used in a variety of applications due to their simplicity, reliability, and low cost. They are often found in sensors for detecting the presence or absence of a magnet, such as in door and window alarms, proximity sensors, and level indicators. They are also used as limit switches in machinery and as components in relays. The activation distance of a reed switch can be adjusted by varying the strength of the magnet and the sensitivity of the reeds.

There are different types of reed switches, including normally open (NO), normally closed (NC), and changeover (CO) contacts. A normally open switch is open when no magnetic field is present and closes when a magnetic field is applied. A normally closed switch is closed when no magnetic field is present and opens when a magnetic field is applied. A changeover switch has a common contact and can switch between two other contacts. Reed contacts are sensitive to shock and vibration, and their lifespan can be affected by the amount of current they switch.