How to Calculate the Inductance of a Ferrite Inductor

Ferrity inductors are common place in electronics.
••• Hemera Technologies/PhotoObjects.net/Getty Images

Things You'll Need

  • Calculator
  • Inductance meter

Ferrite inductors have a ferrite core. Ferrite is a class of ceramic material with strong electromagnetic properties such as high permeability in combination with low electrical conductivity. Ferrite inductors are deployed in a variety of electric circuit applications such as broadband, power conversion and interference suppression.

    Make a simple ferrite inductor by wrapping at least 20 turns of wire around a ferrite rod. Using an inductance meter, measure the inductance of that rod. Record the inductance as "L" and the 20 turns as "N."

    Calculate the AL value of the ferrite inductor. The AL value is the base relationship between the inductance, with a given ferrite core, and the number of turns. Calculate the AL value using the following formula: AL = [(100/N)^2)] x L.

    For example, if your measured value of L in Step 1 is 25 uH, the corresponding AL value will be: AL = [(100/20)^2] x 25uH =( 5^2) x 25uH = 25 x 25uh = 625 uH.

    Use your AL value to calculate the inductance for various values of N using the following formula: L = AL/[(100/N)^2].

    For example: If N is 15, L = 625/[(100/15)^2] = 625/[6.66^2] = 625/44.4 = 14uH.

    If N is 25, L = 625/[(100/25)^2] = 625/[4^2] = 625/16 = 39uH.

    If N is 30, L = 625/[(100/30)^2] = 625/[3.33^2] = 625/11.1 = 56.3uH

    As you can see, the inductance increases as N increases. This is because by placing more turns of wire around a loop, it concentrates the magnetic field into a smaller space, where it can be more effective and create more inductance.

Related Articles

Homemade Resistors
How to Calculate Toroidal Transformers
What Is a Ferrite Clamp?
How to Calculate Induced Armature Voltage
How to Measure the Ohm Value for an Inductor
How to Find Wattage With Voltage & Frequency
Three Ways to Make an Electromagnet Stronger
How to Store Energy by Using Dynamo
How to Calculate the Henrys in a Coil
How to Calculate the Field Current in a DC Motor
How to Calculate CT Ratio
What Is a Toroid Coil?
How to Calculate the Length of Wire to Make a Coil
How to Calculate the Inductance of a Coil
How to Type a Mixed Fraction in a TI-83 Plus
How to Size a Transformer KVA
How to Calculate the Length of Cable on a Drum
How to Strengthen an Electromagnetic Field
How Does a Toroidal Transformer Work?
What Is Zinc Alloy?

Dont Go!

We Have More Great Sciencing Articles!