Home / Applications / Technologies / Inductive loop

Induction loop

“Induction loop" is a term used to describe an electromagnetic detection system, which relies on the fact that a moving magnet will induce an electrical current in a nearby conductive wire.

Inductive loops generally consist of a resonant circuit, formed by a circuit (loop(s) of copper wire) with a certain inductance combined with a specific capacitance. The latter one is defined by a particular electric resonant frequency, which is monitored by a microcontroller.

If a conductive object is approaching the resonant circuit, the latter one is "detuned” (i.e. the inductance of the copper wire and therefore the resonant frequency of the capacitance is changed) by the wire’s proximity to the conductive object. This change is monitored/detected by the microprocessor.

The detected object may be metallic (metal and cable detection, detection of forklifts, pallet trucks, cars, trucks, etc.) or conductive/capacitive (stud/cavity detection). Configurations of this equipment using two or more receiving coils are also possible. In this case the detected object modifies the inductive coupling or alters the phase angle of the voltage induced in the receiving coils relative to the oscillator coil.

Although this technology is well established, it does not fit all kinds of environment and situations; furthermore, its installation and implementation are consistent.