How To Build a Magnet Charger for $40

There have been at least two magnet charger papers in Gas Engine Magazine over the years. The first, which I consider to be the gold standard charger, was written by John Rex in the January 1989 issue of GEM. The second being Build Your Own Magneto Charger by Peter Rooke in the April/May 2020 GEM. Both of these are major projects to build, especially the Rooke unit, requiring a lathe for metal working and coil winding. They weigh in the neighborhood of 150 pounds and are large and difficult to move. And to build them is expensive, as the copper wire required costs several hundred dollars.

This paper uses new rare earth magnet technology to build a bare bones charger that is stronger than the Rex and Rooke chargers, can be built in 5 minutes, costs less than $40 to build, measures 2-1/2-by-12-inches, and weighs less than 5 pounds. In summary, it works well, is easy to build, and is inexpensive and portable.

As the magnets in old magnetos by Peter Rooke in , April/May 2020.