| 摘要 |
<p>An apparatus comprises: a permanent magnet 2 providing magnetic flux, an electric field generator 12 comprising at least one conductive loop 14 and high permeability material 16 configured to direct magnetic flux preferentially through the at least one conductive loop 14 adjacent a first portion 17 but not past a second portion 18 of a length of the at least one conductive loop and a supporting system 20 comprising springs 20 configured to support the permanent magnet 2 at a distance from the electric field generator and enable relative movement between the permanent magnet and the electric field generator. The apparatus may comprise an elliptical form having the high permeability material forming a section 32 of the elliptical shell and low permeability material forming section 34. Eddy current may be reduced by insulating parallel strips forming barriers within the high and low permeability material (figs 5a,5b), which strips may overlap adjacent the boundary 40. The suspension may comprise four springs (fig 4) and addition mass may augment the inertia of the magnet (figs 6a,6b). The boundary of the high permeability section may deviate from the locus 42 (figs 3a,3b,3c).</p> |
