Abstract: An automatic power generating flash wheel assembly comprises at least a fly wheel and at least a coil unit. The fly wheel is enclosed by a transparent outer wheel. At least an inserted groove is formed in the inner periphery of the fly wheel to receive a set of the coil unit. Each of the coil unit has a couple of electrodes at one side and a light-emitting device at the opposite side. The electrodes are disposed toward a pivot. An annular magnet has a recess formed in the inner periphery of the magnet. A protrusion rib on the pivot is inserted through the recess. The magnet touches the electrodes slightly. The magnet is disposed between the first and second annular pivot sockets. The pivot passes through the first pivot socket, the magnet and the second pivot socket. The first pivot socket, the magnet and the second pivot socket are disposed in the fly wheel.