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Main >> Applications >> Sample problems >> Inductive sensor

Inductive position sensor is based on a principle of measuring the electric voltage on the resistor in the circuit with variable inductance, which depends on the mutual position of the sensor components.

**Problem type:**

Plane-parallel problem of AC magnetics.

**Geometry:**

**Given:**

The number of turns in the coil *N* = 210

AC voltage frequency *f* = 400 Hz

Source voltage *U* = 24 V (root mean square)

Load resistor *R* = 1 Оhm

Air gap 0.1 - 0.6 mm.

**Task**

Calculate the voltage across the load resistor of the sensor as a function of the air gap size.

**Solution**

When the position of the rotor changes, the inductance of the coil changes. The joint simulation of the magnetic field and the electric circuit is performed.

In the electric circuit, the amplitude value of the source voltage must be specified, i.e. U * sqrt (2).

To automate the calculations, the LabelMover add-in is used, which moves the rotor by 0.1 mm increments, solves the problem and measures the voltage drop across the load resistor.

**Result**

Magnetic flux density distribution in the core, electrical circuit with load resistor and output voltage for various air gap sizes.