Patents by Inventor Roland H. Fichtner

Roland H. Fichtner 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).

  • Loudspeaker protection network
    Patent number: 4023074
    Abstract: A conventional complementary symmetry push-pull type of current amplifier is modified by the inclusion of a diode which permits the predriver transistor, which otherwise would be turned off, to be turned on, when one of the fuses between the power supply and the amplifier blows, thereby maintaining the D.C. input to and hence the D.C. output of the amplifier at essentially zero volts and keep D.C. off the direct coupled loudspeaker.
    Type: Grant
    Filed: November 21, 1975
    Date of Patent: May 10, 1977
    Assignee: Electrohome Limited
    Inventor: Roland H. Fichtner