Patents by Inventor Matthias Landgraf

Matthias Landgraf 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).

  • Pulse conditioning circuit for controlling electrically controllable valves in a hydraulic control apparatus
    Patent number: 4748345
    Abstract: Pulse conditioning device for electrically controlling valves in hydraulic control apparatus whereby a regulating signal is transmitted to the actuator of the respective electrically controllable valve. A filter is connected to the input side of an isolating transformer and a unidirectional rectifier is serially connected to an input side of the isolating transformer through the filter. An oscillator generates a sinusoidal output signal and a summing amplifier receives both the regulating signal and the sinusoidal signal to provide an output signal which is input to the unidirectional rectifier. To complete a modular pair of identical circuits for the control circuit, a second unidirectional rectifier is serially connected to a second filter and also connected to the output side of the isolating transformer.
    Type: Grant
    Filed: April 8, 1987
    Date of Patent: May 31, 1988
    Assignee: Klockner Ferromatik Desma GmbH
    Inventor: Matthias Landgraf