Vibration Energy Harvesting Concept using a Balanced Armature Transducer.

摘要

Balanced armature transducers are used as the speakers in most hearing aids and in some small insert earphones. In this size range, the balanced armature speaker is a more efficient audio generator than other technologies. This project has investigated the possibility of using these same or similar balanced armature devices in a reciprocal configuration as the generator for vibration energy harvesting. Earlier work by Vitt Nikolas T. Vitt, 'Investigation of a balanced-armature transducer for vibrational energy harvesting,' M.S. thesis, Penn State University, 2011 has shown insufficient output if the device is mounted conventionally, but that a useful output of approximately 100-200 //W/g could be available if the transducer were mounted by its armature. Of course, Vitt knew that mounting by the armature alone is unrealistic, but suggested that possibility as a best case estimate of the output that might be available from a more realistic mounting. This paper examines that possibility in more detail, and suggests a conceptual mounting configuration that can generate an output in the range suggested by Vitt for single frequency vibration input, with output perhaps as great as 1 mW given a wideband vibration source providing 1 g/sqrt(Hz).