Patents by Inventor Thomas Stefan

Thomas Stefan 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 circuit arrangement for sensor-less detection of the rotational angle of a damper-less synchronous machine, preferably excited by a permanent magnet, and supplied by a rectifier
    Patent number: 5339012
    Abstract: A method and circuit arrangement for the sensor-less detection of the angle of rotation of a synchronous machine without a damper is disclosed. According to the disclosed method and circuit arrangement, measuring signals are used which correspond to voltage jumps or pulses generated by a rectifier and the measuring data obtained are provided to a calculating device which calculates the position of the rotor from the dependence of the stator reactance, whereby premagnetization is set when the synchronous machine is started and a measurement is made on each field weakening and strengthening effect. The advantage of the invention resides in both its high precision and the fact that no additional analog current sources are needed to locate the magnet wheel. In addition, the magnet wheel can be located at any load.
    Type: Grant
    Filed: February 11, 1993
    Date of Patent: August 16, 1994
    Assignee: Elin Energieanwendung GmbH
    Inventors: Manfred Schroedl, Thomas Stefan