Patent Protection

Five patents have been granted on this technology.  Raven Technology holds exclusive license rights to this technology and these patents.  International patents are pending.  (The US Government has a stated interest and royalty-free-right in those patents marked with a (*).)

  • (*) US Patent 6,051,959 “Apparatus for Resonant Excitation of High Frequency Alternator Field” – Christopher N. Tupper April 18, 2000.
  • US Patent 6,133,699 “Low-Loss Magnet Core for High Frequency Claw-Pole-Type Alternator” – Christopher N. Tupper, October 17, 2000.
  • US Patent 6,177,746 B1 “Low Inductance Electrical Machine” – Christopher N. Tupper and Duncan G. Wood, January 23, 2001.
  • US Patent 6,175,178 B1 “Low Inductance Electrical Machine for Flywheel Energy Storage” Christopher N. Tupper and Duncan G. Wood, Jan 16, 2001.
  • (*)US Patent  6,570,370 B2 “Apparatus for Automatic Tuning and Control of Series Resonant Circuit”  – Christopher N. Tupper and Duncan G. Wood, May 27, 2003.
  • US Patent 7,071,657 B2 “Method and Apparatus for the Production of Power Frequency Alternating current Directly form the Output of a Single-Pole Type Generator” – Christopher N. Tupper and Duncan G. Wood, July 4, 2006.


Raven recently filed an additional patent covering generator configurations that will produce three phase grid quality power from variable speed inputs.