Understanding Inductors in Parallel

In electrical engineering, when inductors are connected in parallel, the total inductance (equivalent inductance) decreases, similar to how resistors behave when connected in parallel. This configuration is commonly used in RF circuits and power supply filters where a specific inductance value is required that isn't available as a standard single component.

The Formula for Parallel Inductance

The formula for calculating the equivalent inductance (L_eq) for multiple inductors in parallel, assuming no mutual inductance (coupling) between them, is:

1 / L_eq = 1 / L₁ + 1 / L₂ + 1 / L₃ + ... + 1 / L_n

Essentially, the reciprocal of the total inductance is equal to the sum of the reciprocals of each individual inductor's value. If you have only two inductors, you can use the simplified "Product over Sum" formula: (L1 × L2) / (L1 + L2).

How to Use This Calculator

1. Enter the value of your first and second inductor in the respective input fields.
2. Choose the correct unit (Henry, Millihenry, or Microhenry) for each component.
3. Click "+ Add Inductor" if you have more than two components in parallel.
4. Hit the "Calculate" button to see the total equivalent inductance displayed in various units.

FAQs

Does parallel connection increase current capacity?

Yes, connecting inductors in parallel allows the total current to be split between the branches, which can be useful for high-power applications, provided the inductors are rated correctly.

What happens if there is mutual inductance?

This calculator assumes no magnetic coupling between the inductors. If the inductors are placed very close to each other, their magnetic fields may interact, requiring a more complex formula that includes the coupling coefficient (k).

Why is my total inductance lower than the smallest inductor?

That is mathematically correct. In a parallel circuit, the total inductance will always be smaller than the value of the smallest inductor in the parallel group.