The secret of free energy was never quite revealed. Skeptics often make intelligently-cheeked remarks about this topic. Older documents may refer to it as the Hummel Machine .
More info is available at The Mad Scientist's Lair .
Technical Sites These have machine descriptions, pictures, and theory. John Bedini's Page This has plans and pictures for several devices, including several of his own design. Bill Beaty's Weird Science page. This has links to many other sites. The Mad Scientist's Lair David Jonsson's Elektromagnum electromagnetics page.