Old School Proximity Sensor Implementation

Most inductive proximity sensors have a set of standardized behaviors and a designer's understanding of these behaviors can lead to successful implementation while avoiding the pitfalls typically associated with these sensors. Inductive proximity sensors generate a magnetic field from their detection faces. Whenever a detectable object moves into the sensor's field of detection, Eddy currents build up in the target and dampen the sensor's magnetic field. This effect triggers the sensor's output. Since a current in the target is needed for detection, inductive proximity sensors are uniquely suited for detection of all types of metals. Inductive proximity sensors come in two forms, shielded and unshielded. A shielded inductive proximity sensor can be embedded flush in its mounting material without affecting the sensor's field of detection. The unshielded inductive proximity sensor has the advantage of longer sensing distances, but the disadvantage of not being embeddable.