An inductive energy harvester comprises a permanent magnet magnetic field source attached by a pair of compact spiral disk springs to an induction coil. The springs position the magnet so that the induction coil surrounds one end of the magnet where the flux density is greatest. In addition, the magnetic flux emerging from that end of the magnet is enhanced by a disk of magnetic material having high permeability and high flux density. In another embodiment, the magnetic field source comprises two dipole magnets arranged in opposing flux relationship with a thin layer of high flux density, high magnetic permeability material located in a gap between the magnets.