Proximity switches represent a broad class of sensors.  Various types include optical, electrostatic, thermal, or magnetic devices.  Magnetic sensors may be divided into the induction or dynamic type and the direct field detectors or static type.  A proximity switch, activated either by an electromagnet (coil) or a permanent magnet, is most often classified as a relay  when it incorporates electrical contacts.  The general concept is that a switching action takes place without any physical contact.

The reed relay hermetically sealed in a glass envelope is a classical example of a static magnetic proximity switch.  Most references to it may be found in literature related to relays.

The Jackson proximity switch or proximity relay may be actuated by either electromagnets or permanent magnets.  It may be substituted for Hall Effect Sensors or Induction Proximity Sensors, depending upon the application.  Reliability is limited only by the quality of the electrical contacts used in a particular design.  This technology has unlimited power handling capability.  It can be ruggedized to handle virtually any environment.  It radically out performs the reed switch.

Typical fields of application are:

• Automotive
• Electronic Physical
• Industrial position sensors
• Security Radio Frequency circuits
• Telecommunications relays