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Unformatted text preview: esonant circuit coil (4) High-frequency magnetic field (2) Energy is drawn from the high-frequency magnetic field (5) Active surface (3)
a) Proximity sensor unactuated (oscillator unattenuated)
b) Proximity sensor actuated (oscillator attenuated) Fig. 4.1.2: Method of operation of an inductive proximity sensor Only electrically conductive materials can be detected by means of inductive
Depending on switch type (normally open contact or normally closed contact), the
final stage is switched through or inhibited if a metallic object is present in the active
switching zone. The distance to the active area, where a signal change of the output
signal occurs, is described as the switching distance. The important criteria for
inductive proximity sensors is therefore the size of the coil incorporated in the
switching head. The bigger the coil, the greater the active switching distance.
Distances of up to 250 mm can be achieved. 50 © Festo Didactic GmbH & Co. KG • FP 11...
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- Spring '12