Patents by Inventor Earl R. Fredrich

Earl R. Fredrich 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).

  • Tornado warning system
    Patent number: 4812825
    Abstract: A tornado warning system uses a superhetrodyne receiver to detect electromagnetic energy produced by a tornado. The automatic gain control signal of the receiver is used to generate an intermediate signal having a time duration corresponding to the time when the automatic gain control is at or above a predetermined level. The intermediate signal is of constant amplitude and is integrated. Upon the integration reaching a predetermined level, an alarm initiate signal is produced which turns on an alarm drive and, in turn, sounds an alarm.
    Type: Grant
    Filed: February 10, 1987
    Date of Patent: March 14, 1989
    Assignee: K Electronics, Inc.
    Inventors: Richard E. Kennedy, Earl R. Fredrich