Patents by Inventor Dacon Chow

Dacon Chow 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).

  • Publication number: 20050062494
    Abstract: A stall detection circuit and method for a stepper motor. The circuit has an H-bridge configuration with an additional circuit pathway to ground being connected at a point between two center windings. During the transition between step sequences, the circuit employs a monitoring phase in which the previously active low side driver is turned off such that current passes through only the first winding and then is diverted to ground via the additional pathway. While the phase voltage is thus momentarily extinguished, the second coil is used to monitor the motor's back EMF, from which it can be determined whether the rotor is in a normal running mode, a stall, or a reverse condition.
    Type: Application
    Filed: September 24, 2003
    Publication date: March 24, 2005
    Inventors: Tanh Bui, Dacon Chow