#### Glebiys

##### Newbie level 6

I'm selecting ferrite core to create a resonant inductor in an LLC converter.

Required parameters of the inductor:

1) Inductance - 18.2uH

2) Max current - 13A (3.3kW)

3) Frequency range(min-max) - 100-400kHz

I'm only now dealing closely with the construction of inductors.

After studying some information, I realized:

- The ferrite parameters indicate the value of the inductance per turn (AL), through it you can find out the final inductance: L = AL * N^2.

Since the inductor must be designed for high power and I have not yet quite accurately determined the method for calculating the overall power - I chose the PQ5050 (N87) ferrite, where the inductance of one turn is 6500nH. Based on the formula above and the required inductance, I got a value of 1.67 turns.

This confused me, since powerful inductors usually have many turns.

Ok, I thought it was due to the high cost of such ferrite and started looking for ferrites with lower AL values already having an air gap.

AL:

1) 1uH = 4.26 turns

2) 700nH = 5.09 turns

3) 100nH = 13.49 turns

Something is closer, but still it seems to me that something is wrong.

I found a similar powerful inductor. The diagram shows that it is big dimensional and there are many turns.

**Question:**Would a large number of turns on an inductor be better than a smaller number?

Or am I doing something wrong?

I have not seen powerful inductors with 1-2 turns.

Thank you!