Thomas Henry Moray
Thomas Henry Moray (August 28, 1892 - May 18, 1974) was an inventor from Salt Lake City, Utah. He received a US patent 2,460,707 in February 1949, after a process of 17 years in discussions with the patent office. The main components of the patent were a LC circuit resonator and a set of vacuum power tubes of diode type using uranium and radium power sources and doped germanium semiconductors on the cathodes. It was an early example of doped semiconductors and a fore runner of radioactive power supplies using radioactive isotopes in space research. Moray's device followed other work on nuclear batteries first done in 1913 by Henry Moseley using a radium source.
Moray's invention was not commercially successful because of the high manufacturing cost compared to the amount of power produced and the small market for atomic powered batteries. Many unsubstantiated claims have been made in connection with attempts to sell books or ask for money. One claim was five kilowatts of electricity produced from a device costing sixty thousand dollars to build in 1926. If true, it represents a high cost for electricity compared to other sources, except in special situations like space research 
A counter culture has developed with claims about alternative energy, citing Moray as a leading example of lost opportunity and of free energy suppression. Since Moray patented his invention with detailed drawings and further described his ideas in books he wrote, the economics and technical operation can be understood with conventional science and engineering. A substantial reduction of manufacturing cost would be required to make wider use of power supplies based on Moray's invention. Vacuum tube circuits have been replaced by solid state electronics in most applications.
- G. Friedlander, J. Kennedy, J. Miller, "Nuclear and Radiochemistry," John Wiley and Son, Inc., New York, 1966.
- "Moray Web".
- D. J. Anderson, "NASA Radioisotope Power Conversion Technology NRA Overview," National Aeronautics and Space Administration, NASA/TM-2005-213981, November 2005.