Compared to bipolar coils, unipolar coils cause cross-coupling between any two coils, not only those inside the same unit but also those among different units. To compensate for the cross-coupling ...

He’s taken a large array of moving-coil panel meters and hooked them up to a microcontroller board that’s triggered by a PIR sensor. Normally the readings are random, but get too close to it ...

Instructables user [birdycrazy] built a winding rig from a PVC pipe and a bunch of K’Nex. He had recently started a Tesla coil project and needed an efficient way to wind the secondary coil.