Inductive Sensors:- Inductive Proximity Switches, self contained, depend on the output of an oscillator for their operation. The oscillator resonant circuit uses an open core coil to produce a concentrated high frequency electromagnetic (RF) field, which emerges from the active surface of the sensor. If a metal target (or other electrically conductive material) enters this field, eddy currents will be induced in it, causing the resonating oscillator to be damped.
The associated electronic circuitry detects the damping of the oscillator, triggers the switching action, and amplifies the output to drive devices such as Relays, Counters, etc. When the target is removed from the sensing field, the reverse action takes place, the undamping of the oscillator is detected and the switch is returned to its original state.
Introduction - 3 Wire DC & 4 wire DC SW 3051/4051/5051/6051/7051:- These switches operate on DC voltages from 5 volts to 240 volts. Standard models operate on 10-30 V DC and can be used
with Logic Circuits, Counters or to drive Relay Coil directly. The output of these switches can be
either PNP or NPN or both. With PNP output, the switching is in the sourcing mode and the load must be connected between the Output and the Negative of the supply. Conversely, with NPN output the switching is in sinking mode & the load must be connected between the output & the positive of the supply. All 3 wire & 4 wire DC switches are internally protected against Inductive voltage peaks, Spurious line pulses, Reverse polarity & Short circuit conditions.