He’s using an armature growler (YouTube link) to test the armature from a generator. Armature growlers (or just growlers for short) were commonplace years ago. Back when cars had generators ...

Maximum efficiency can easily rise another 5 to 10% by optimizing the magnet, housing, and armature lamination dimensions. FEA helped evaluate another design iteration that employed magnet arcs ...

Maximum efficiency can easily rise another 5 to 10% by optimizing the magnet, housing, and armature lamination dimensions. FEA helped evaluate another design iteration that employed magnet arcs ...