Reed Switches

Reed switches consist of two or three ferromagnetic blades (or reeds) hermetically sealled insidea glass envelope. The construction ensures protection from the external environment. Two types are generally available : Form A (normaly open) and Form C (changeover). Sensitivity of a reed switch is measured in ampere turns and it should be noted that lower switch ratings are more sensitive as they require less magnetic field strength to operate them. Various voltage and current switching levels are available and contact plating materials can be varied to accomodate specific types of load. Operation Reed switches are operated by a magnetic field, this may be a magnet or a current carrying coil. When the field is removed the switch reverts to its previous state. Operating by magnet can be achieved in a large variety of ways either moving the magnet toward an away form the reed either perpendicularly of parallel to the glass. Reed switches are used in a variety of Assmetech products including proximity switcches, float swithces and Reed realys. They are also available in moulded packages affording protection from damage and surface mount styles.