Patents by Inventor Wenlin Sun

Wenlin Sun 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).

  • PWM speed-control apparatus for elevators
    Patent number: 5932979
    Abstract: A PWM speed regulating apparatus for DC elevator comprises a rectifier-filter (1), voltage suppressor (2), chopper voltage regulator (3), system controller (4) and a driving protector (5). The speed of DC motor is regulated by a pulse width modulating mode so that the current of the motor is maintained continuously and the ripple of current and torque is lower, and which ensures a good riding quality and a high floor arrival accuracy.
    Type: Grant
    Filed: July 11, 1997
    Date of Patent: August 3, 1999
    Inventor: Wenlin Sun