Patents by Inventor Todd N. Johnstone

Todd N. Johnstone has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Current controlled inductor
    Patent number: 4825184
    Abstract: A current controlled inductor (1) having an inductor coil (4) in one state of alteration attached at one end to a displacing coil (6) in an opposite state of alteration to that of the inductor coil (4). Both coils are formed of a shape memory alloy that when heated to a predetermined temperature will return to an original configuration from an altered configuration. An electric current from a DC source (11) passing through the displacing coil (6), heats the displacing coil (6), causing the coil to contract to an original length and simultaneously pull the inductor coil (4) from its original length thereby changing the inductance effect of the inductor coil (4) on the signal source (12).
    Type: Grant
    Filed: July 6, 1987
    Date of Patent: April 25, 1989
    Assignee: The Boeing Company
    Inventors: Joseph T. Bloch, Todd N. Johnstone