Coil Topology Optimization for Transducers Based on Cylindrical Magnets

Abstract

The previous chapters have been concerned with the optimization and comparison of eight different coupling architectures in electromagnetic vibration transducers. In summary, geometrical dimensions were found which yield to a maximum output power and output voltage, respectively. The comparison of the maximum performance limits yield the most efficient architectures which should consequently be favoured in the application whenever possible. However a basic characteristic of all the architectures (independent of the architecture class) is that the topology of the coil has always been predefined to be cylindrical. Hence the underlying optimization approach is strictly speaking a sizing optimization. Obviously this makes sense because cylindrical coils, especially made of enamelled copper wire, are state of the art and easy to fabricate. Moreover the optimized dimensions (especially for the “Magnet across coil” architecture class) show that the resulting coils are rather thin. Consequently there is not much space left for an optimization of the coil topology. But for all that an interesting question arises from this: