Inductance for a Solenoid

The Inductance for a Solenoid calculator computes the inductance based on the relative permiability, cross-section area, number of coils on the bobbin and the length of the coil.

INSTRUCTIONS: Choose units and enter the following:

• (`mu`) Relative Permiability
• (A_C) Cross-sectional Area of the Core
• (n) Number of Coils on the Bobbin
• (l) - Length of the Coil

Solenoid Inducatance (L):  The calculator returns the inductance in Henries.  However, this can be automatically converted to compatible units via the pull-down menu.

The Math / Science

The Inductance for a Solenoid equation computes the inductance of a coil of wire on a bobbin. 

The bobbin is a spindle shape object that is often used in a transformer. In transformer terminology the bobbin is the structure on which a coil of wire is wound.  

A transformer is for stepping up or stepping down an AC power source by using the principle of magnetic induction between the transformer's two wire windings.   There are a number of calculations in designing or building a transformer.

In general inductors use a ferrite core.  Reducing the Inductance leakage will lead to increase of capacity.  The formula for the Inductance of a Solenoid is:

       `L = ( mu_0 * mu * A_c * n^2)/l`

where:

• L - Inductance for a Solenoid
• `mu_0` is the  permittivity of free space
• `mu` - relative permiability
• `A_C` - cross-sectional area of the core
• `n` - number of coils on the bobbin
• `l` - length of the coil