by using this approach the inductive components can be miniaturized to physical sizes compatible with the requirements of modem surface mount technology for integrated circuitry this process also allows these components to be fabricated using mass production techniques thereby avoiding the need to handle discrete devices during the manufacturing process in another preferred embodiment a series of thin concentric high permeability rings are etched on a substrate to provide high permeability transformers and inductors having minimal eddy current effects application_number US 99490204 A description fig2 illustrates a typical prior art transformer with a toroidal core 30 for simplicity this transformer has two windings of insulated wire a two turn winding 32 and a four turn 34 winding each turn 36 encircles the material of the core 30 such that when electrical current is passed through one winding an encircling magnetic flux path 38 flows within the core 30 fig2 a illustrates the windings 32 34 passing through the center of the core 30 and around the outside of the core 30 preferred embodiments of the present invention have a very different core and winding arrangement in one of these preferred embodiments shown generally in fig3 slab 50 of ferromagnetic material has a top surface 52 and bottom surface 54 and shown in cross sections two outer holes vias 56 and one inner hole via 64 within the slab 50 as described below for miniature inductors and transformers the slab 50 is advantageously a thin layer of ferrite having a relatively high resistivity fig3 a and 3b show a u201c virtual u201d toroid transformer constructed in accordance with one of the preferred embodiments of the invention using the slab 50 with.