Hybrid inductor design

I found myself in need of an inductor with low inductance and high current capabilities. Most bigger inductors like the one below do have a big core but far to much windings causing the saturation current to be fairly low.

So I decided to make my own. I ordered the biggest cores I could find on eBay and some thin copper wire to experiment with. The core has a diameter of 35 mm.

I took a piece of wire and added one winding at a time, measuring the inductance between each turn. After the fourth winding I passed the inductance I was looking for.

Now for the thicker wire. This wire has a diameter of 2mm.

It was very difficult to get this tough wire around the core without damaging it, also I could not get the turns distributed evenly around the entire core. How could I ever get something like this attached to a circuit.

I decided to make a hybrid inductor. Part of the windings will be on the PCB and the rest will be made out of small pieces of copper wire. The PCB traces are on both sides of the board and as wide as possible.

The core goes on top.

And then the wire pieces are soldered in one at a time.

As you can see, this also keeps the core stuck to the board and as a bonus it has a lower profile.

-THE END-