Magnetic Proximity Switches

Magnetic Proximity Switches

Magnetic Proximity Switches have two overlapping flat contacts which are sealed into a glass tube filled with inert gas. When approached by a permanent magnet the contact ends attract each other and make contact. When the magnet is removed, the contacts separate immediately.Reed Switches have an expected life of more than 3 billion switching operations.

When metal passes in front of the switch the magnet inside either makes or breaks an electrical connection depending on if it is a normally open or normally closed type switch. When the metal is removed the switch moves back to its normal position. These are particularly useful in applications where it might be exposed to water since the switch is completely enclosed. Connected to a relay the switch can activate or stop a hydraulic valve when a part has reached its proper position.

Magnetic proximity switches detect magnetic fields at greater distances of up to 60 mm, even through non-ferromagnetic materials like stainless steel. Depending on the permanent magnets used, different sensing distances can be implemented. The permanent magnet can be installed independent of polarity and with large tolerances, which allows many different installation options, even in cramped spaces. Precise switching is thus guaranteed even when used in dirty or damp environments. This means that applications in cranes or heavy vehicles are also easy to implement.