Patents by Inventor Lothar Roth

Lothar Roth 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).

  • Speed control and braking circuit for a series connected DC machine
    Patent number: 4264846
    Abstract: A continuous speed control and braking circuit for a DC propulsion motor having armature and field currents set largely independent of each other to permit operation in the field weakening region of the motor. A direct current control element is pulsed for setting the armature current; a series circuit containing the field winding and a switch is connected in parallel to the DC control element; and a field current bypass diode is shunted across the field winding.
    Type: Grant
    Filed: December 11, 1978
    Date of Patent: April 28, 1981
    Assignee: Siemens Aktiengesellschaft
    Inventors: Helmut Sauer, Peter Loderer, Lothar Roth, Klaus Breuer