Often coils have to be custom made for your application. I started making my first coil by simply taking a bobbin and wire and winding the coil by hand (see left). This can be a very boring job. So it was time for a simple winder that is cheap and easy to build. I didn’t want to wind by hand and count the windings in my head any more. So the winder had to have a motor, a rotary encoder and an arduino to do the counting job. Continue reading →