over- +‎ unity (the number "1"), referring to the fact that an over-unity device should produce more energy than it receives as input. Coined to avoid patent rules that prevent impossible technologies such as perpetual motion machines being patented.


over-unity (not comparable)

  1. (euphemistic) Free-energy; supposedly capable of perpetual motion
    • 1994, David Hatcher Childress, The Free-energy Device Handbook: A Compilation of Patents & Reports, Adventures Unlimited Press →ISBN, page 90
      Look for the "over-unity" ratio when calculating energy output versus input as a proof of free energy.
    • 2007, Florentin Smarandache, V. Christianto, Hadron models and related New Energy issues, Infinite Study →ISBN, page 96
      The system behaves as an over-unity device producing energy from atomic hydrogen by a repeated dissociation and recombination of hydrogen atoms. MAHG tube contains a vacuum tube filled with hydrogen at 0.1 atm and cooled by water.
    • 2008, Mark P. Silverman, A Universe of Atoms, An Atom in the Universe, Springer Science & Business Media →ISBN, page 25
      "The Potapov device," the experimenters reported ruefully, "did not show any evidence of over-unity performance in our tests. We can find no explanation for the failure of this Potapov device to perform as reported (300% over-unity)."