If you build electronics, you will eventually need a coil. If you spend any time winding one, you are almost guaranteed to think about building a coil winder. Maybe that’s why so many people do.

Finding just the right off-the-shelf part to complete a project is a satisfying experience – buy it, bolt it on, get on with business. Things don’t always work out so easily, though, which often ...

The resulting charge can be stored in a battery cell or other power reservoir. Alternatively, the device might use the same magnetic field to wind a spring or coil. Similar to a timepiece, the coil ...