Patents by Inventor Fred Tamjidi

Fred Tamjidi 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).

  • Method and apparatus for transfer of a critical load from one source to a back up source using magnetically latched relays
    Patent number: 7535129
    Abstract: An automatic transfer switch includes first and second magnetically latched relays that respectively connect first and second voltage sources to a critical load. The first and second relays are magnetically latched in their respective opened or closed positions by a permanent magnet so that no holding current is supplied to the relays after switching is completed. As such, no holding current is required for either relay in the non-transferred or the transferred state of the automatic transfer switch, which reduces heat generated by the relays which can lead to relay failure. A switching method uses the automatic transfer switch to switch voltage sources without requiring relay holding currents in either the non-transferred or transferred state. A method of reducing contact bounce is also disclosed.
    Type: Grant
    Filed: May 16, 2007
    Date of Patent: May 19, 2009
    Assignee: TwinSource, LLC
    Inventors: David R. Phelps, Fred Tamjidi
  • Method and apparatus for transfer of a critical load from one source to a back up source using magnetically latched relays
    Publication number: 20080054722
    Abstract: An automatic transfer switch includes first and second magnetically latched relays that respectively connect first and second voltage sources to a critical load. The first and second relays are magnetically latched in their respective opened or closed positions by a permanent magnet so that no holding current is supplied to the relays after switching is completed. As such, no holding current is required for either relay in the non-transferred or the transferred state of the automatic transfer switch, which reduces heat generated by the relays which can lead to relay failure. A switching method uses the automatic transfer switch to switch voltage sources without requiring relay holding currents in either the non-transferred or transferred state. A method of reducing contact bounce is also disclosed.
    Type: Application
    Filed: May 16, 2007
    Publication date: March 6, 2008
    Inventors: David Phelps, Fred Tamjidi