Performance characteristics of a shake flashlight

The paper deals with an analysis and experimental tests on a shake flashlight. A shake flashlight has a built-in linear moving-magnet generator with stationary coil. Analytical equations for the induced EMF, current, voltage, electromagnetic force and power have been derived. A special shaker for experimental tests have been designed and fabricated. The results of laboratory tests have been compared with analytical calculations. The output electric power, in comparison with other energy harvesting devices, is high; in the investigated shake flashlight from 10 mW do 170 mW. A NiMH battery that is charged by shaking the flashlight allows for lighting the LED from several seconds to a few minutes.