I was working recently on a design where I needed custom high-temperature magnetics for a new application. Nothing like what I needed was available off the shelf. My vendor had some different high-temperature magnetics, but they weren't in the correct size or shape. The task was to come up with a design that met my requirements using the factory's tooling and cores. Then came the hard part: coming up with a design that would meet the new operating inductance and frequency requirements on the old core.
Coming up with the design (wire size and turns) that would do this without sending the production department through a batch of trial-and-error tests was more difficult than it first seemed. I took a couple of approaches. First, I used the magnetics design software described below to take a pass at the problem. I then compared this answer to the results from a set of formulas from a paper from the University of Colorado's Department of Electrical, Computer, and Energy Engineering.
The software I used is Magnetics Designer from Intusoft. The company says the software is intended for designing single- and multi-layer inductors and transformers. It will also generate a Spice model. Intusoft goes into lots more detail on its site — core material, bobbin size, wire types, PC board trace dimensions, etc. This quote pulled from the site should provide a bit more background.
Typical design applications include high frequency switching regulator transformers and output chokes for off-line, full-wave and forward converters, 60 Hz single-phase line transformers, AC inductors, planar magnetics and 400 Hz aircraft transformers. Virtually any single phase, layer wound inductors or transformers that range from 10Hz to over 5MHz can be synthesized with Magnetics Designer.
It looks like the program gives you plenty of flexibility to change every design parameter you could conceive and a few more that you couldn't.
And it provides reasonable information for the simulation.
After some back and forth, the two answers were reconciled, and I completed a successful first pass prototype.
What is your experience with inductor design?