Many low frequency inductors used in long and medium wave receiver design require a few hundred turns of wire. Winding the coils by hand can be troublesome, especially if you lose count along the way. This simple coil winder is easy to build and spins the coil former clockwise or anticlockwise while keeping track of the turns and displaying the exact value with a resolution of one tenth of a turn.
 
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This coil winder design, as the name suggests, is used to wind coils. It keeps track of the number of turns and the direction of rotation with the help of an encoder disc mounted on a motor shaft. The disc is divided into ten sections alternating black and white. Two opto-sensors are used to register the turn of the disc in either direction. Clockwise rotation of the motor shaft increments the value shown on an LED turns-counter display while counter-clockwise rotations decrement the value.