The current enclosed by the dashed line is just the number of loops times the current in each loop. Therefore the slope of the current curve before and after the plunger movement will be different. The inductance can be calculated in a manner similar to that for any coil of wire. Approximate Inductance of a Toroid. For single turn loops, Maxwell's elliptic integral formula is used. This is a single purpose calculation which gives you the inductance value when you make any change in the parameters. The formula for calculating the inductance of an air-core single-layer solenoid is: The formula for calculating the inductance of an air-core multi-layer solenoid is: The formula for calculating the inductance of an air-core flat spiral coil is: WhereN = Number of turnsr = Coil radius in inchesl = Coil length in inchesd = Winding depth in inchesL = Inductance in microhenrys (μH), Coil Geometry: Select the geometry of your coil from the list. Coil Inductance Calculator This calculator helps you compute the inductance of a coil. The application of Faraday's law to calculate the voltage induced in the toroid is of the form. Inputs. Relative Permeability . Solenoid Inductance Calculator Rectangular Coil Calculator. It means that self-inductance L depends on how effective the current is in creating flux; the more effective, the greater ΔΦ/ ΔI is. Base Inductance is the Lorenz Current Sheet value which contains no corrections, or the Maxwell formula value, … This calculator uses the Lorenz solenoid current sheet formula for coils having more than one turn. Use the Coil Inductance Calculator to calculate the inductance of air-cored single-layer solenoid, multi-layer solenoid and flat spiral coils. Amperes law then gives the magnetic field at the centerline of the toroid as. Using the centerline value for magnetic field as an average introduces an error which is small if the toroid radius is much larger than the coil radius. You can choose from single-layer solenoid, multi-layer solenoid and flat spiral coil forms, Length: Enter the coil length, measured as depicted in the diagram above, Diameter: Enter the coil diameter, measured as depicted in the diagram above, Depth: Enter the winding depth, as depicted in the diagram. The algorithm explained in [6] measures the slope of the current curve at three different instances and compared to detect the position of This calculation is approximate because the magnetic field changes with the radius from the centerline of the toroid. For larger values of inductance and for transformers, iron is used as a core material. Finding the magnetic field inside a toroid is a good example of the power of Ampere's law. inductance of the solenoid depends on the plunger position.