Patents by Inventor Friedrich Lippl

Friedrich Lippl 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: 4737721
    Abstract: The invention relates to a frequency doubling circuit for the sinusoidal and cosinusoidal signals emitted by an angular step generator. According to the invention, four comparators are provided, while the sinusoidal signal is located at the non-inverting inputs of the first and the second comparator, the inverted sinusoidal signal is located at the inverting input of the first comparator and at the non-inverting input of the fourth comparator, the cosinusoidal signal at the non-inverting input of the third comparator, and the inverted cosinusoidal signal at the inverting inputs of the second to fourth comparator. Further, two XOR gates are provided, while the outputs of the first and third comparator are located at the inputs of the first XOR gate and the outputs of the second and fourth comparator are located at the inputs of the second XOR gate.
    Type: Grant
    Filed: August 13, 1987
    Date of Patent: April 12, 1988
    Assignee: Siemens Aktiengesellschaft
    Inventor: Friedrich Lippl