Electric power supply system for portable miniature size power consuming devices

An electric power supply system for portable miniature size power consuming devices, comprising an AC generator, a rechargeable battery and a charging device to be fed from the AC generator and maintaining the battery charging level, the AC generator comprising a multi-polar rotor wheel having permanently magnetized poles, a stator having one or more windings providing an AC current and an eccentric mass driving the permanently magnetized rotor wheel;

• the rotor wheel, the stator and the eccentric mass being mounted coaxially, a transmission being arranged between the eccentric mass and the rotor wheel characterized in that the transmission is a loose coupling means that selectively engages the rotor wheel by overcoming magnetic fields interacting between the poles of the rotor wheel and the respective poles of the stator, wherein the loose coupling means comprises a plate attached to the rotor wheel carrying along its periphery a torus-shaped tube divided into one or more sealed sections, the eccentric mass comprising an amount of material distributed over the tube sections, the volume of the distributed material in each tube section being considerably less than the volume of the respective tube section so as to be able to move within said tube section, such movement causing a lurching movement of said plate which, in turn, overcomes the magnetic fields interacting between the poles of the rotor and the poles of the stator to cause rotation of said rotor wheel until the poles of said rotor wheel against interact with the respective poles of said stator.