Patents by Inventor Adrian J. Morgan

Adrian J. Morgan 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).

  • Electret microphone circuit
    Patent number: 4361735
    Abstract: An electroacoustic transducer for a microphone comprises an electret wherein an additional capacitance substantially greater than the capacitance normally inherent in the electret is connected in parallel with the electret. The additional capacitance may be of the order of 10 times greater than the capacitance normally inherent in the electret and may be produced inherently in the transducer or by a separate component connected to the transducer.
    Type: Grant
    Filed: May 5, 1980
    Date of Patent: November 30, 1982
    Assignee: The Post Office
    Inventors: Edward G. T. Johnson, Adrian J. Morgan
  • Electret transducer backplate, electret transducer and method of making an electret transducer
    Patent number: 4249043
    Abstract: An electret transducer backplate is made of a thermo-softening plastics material rendered electrically conducting by electrically conducting particles distributed therethrough. An electret foil diaphragm is mounted on the backplate and the relative flexural rigidities of the diaphragm and the backplate are such that, in use, the deflection of the diaphragm is at least twenty times as great as the deflection of the backplate. A method of making the transducer involves heating an electret foil, bonding the electret foil to a retaining ring while the foil is hot and securing together the retaining ring and the backplate.
    Type: Grant
    Filed: November 28, 1978
    Date of Patent: February 3, 1981
    Assignee: The Post Office
    Inventors: Adrian J. Morgan, John K. Williams, Ronald Else