US Patent 7254938 Power supply and transformer

A circuit for providing a potential difference across a gap between two electrodes of a fuel reformer, oxides of nitrogen trap or soot filter regenerator for an internal combustion engine or the like. The circuit includes a power source, a transformer including a primary winding and a secondary winding for coupling across the electrodes. The power source is coupled to the primary winding. A switch or switches is/are coupled to the primary winding.