# Inductance Calculation for a Toroid Core?

I have a Toroid Core listed here: LINK , i have T130-52 . I have all the values of the core from this sheet. Now i need to build an inductor out of this toroid. How do i determine which wire to wound, and how many turns would give me what inductance?

Look under $A_L$ to see the core's inductance factor, which is the expected inductance (in nanohenries) per turns squared.

$A_L = \dfrac{L}{turns^2}$

So, with some algebra:

$L = A_L \cdot turns^2$

$turns = \sqrt{\dfrac{L}{A_L}}$

As for the wire size, choose appropriately based on your expected current (which you haven't specified), the diameter of the wire and the available space on the core.

• Thanks. Does the wire size/gauge thickness also effect the inductance? Commented Sep 22, 2013 at 23:24
• Not really. A turn is a turn when it comes to inductance factor. How you wind the inductor influences things like stray capacitance and leakage inductance (if you have multiple windings). Commented Sep 22, 2013 at 23:58
• I havent made inductors myself before. Is leaving some gap between the wires a good practice to counter the stray caps and inductances. Anything else i should keep in mind while making it? Commented Sep 23, 2013 at 0:01
• Generally, uniformly spreading the wire around the toroid and keeping the turns as uniform as possible is a good practice. Try to keep things in a single layer if possible as well. Machines exist that wind turns onto toroids but doing it by hand is possible (with practice). Commented Sep 23, 2013 at 0:08