Patents by Inventor Michael T. Fegan

Michael T. Fegan 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).

  • Patent number: 4621240
    Abstract: In the horizontal drive of a raster scanned video display, a free running astable multivibrator responsive to a synchronization input signal provides a horizontal output signal to horizontal deflection circuitry for synchronizing the video display's raster scan with the video information presented thereon. The astable multivibrator includes a pair of coupled transistors which are alternately rendered conductive in accordance with the time constant of a respective RC network associated with each transistor. To compensate for the temperature-dependent operation of the transistor pair which causes the multivibrator's operating frequency to increase with increasing temperature, a pair of back-to-back coupled diodes are connected to provide the synchronization input signal to one RC network so as to increase the charge on a capacitor within the network, the time constant of which is similarly increased. The temperature-dependent change in voltage across the diodes compensates for the change in V.sub.
    Type: Grant
    Filed: June 28, 1985
    Date of Patent: November 4, 1986
    Assignee: Zenith Electronics Corporation
    Inventors: Robert J. Alvord, Robert Amberg, Michael T. Fegan, Joseph Kadlec