Low leakage filtered power supply

In an AC power supply system having a transformer structure that includes primary and secondary windings and a core, and a filter structure including capacitors and inductors, wherein said filter structure has an electrical center which is normally connected to system ground, the improvement for reducing leakage current with respect to system ground comprising a center tap on said secondary transformer winding connected to said electrical center of said filter structure, said transformer and filter structures being electrically isolated from system ground, in which said filter structure includes a conductive housing which is electrically connected to said center tap.