Patents by Inventor Choi Yeongha

Choi Yeongha 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).

  • Multi-channel digital amplifier for shifting phases of PWM signals
    Patent number: 6731162
    Abstract: Disclosed herewith is a multi-channel digital amplifier. The multi-channel digital amplifier includes a PWM converter, switching circuits, and low pass filters. The PWM converter converts an input signal to N low power PWM signals (N is two or more). The switching circuits amplifies the N low power PWM signals to generate N high power PWM signals. The low pass filters convert the N high power PWM signals to analog signals inputted to a plurality of speakers. The phases of the N low power PWM signals are made to be different from each other to make the on/off times of the semiconductor switching elements of the switching circuit to be different.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: May 4, 2004
    Inventors: Choi Yeongha, Park Kyoungsoo, Sung Koeng-Mo
  • Multi-channel digital amplifier for shifting phases of PWM signals
    Publication number: 20030006838
    Abstract: Disclosed herewith is a multi-channel digital amplifier. The multi-channel digital amplifier includes a PWM converter, switching circuits, and low pass filters. The PWM converter converts an input signal to N low power PWM signals (N is two or more). The switching circuits amplifies the N low power PWM signals to generate N high power PWM signals. The low pass filters convert the N high power PWM signals to analog signals inputted to a plurality of speakers. The phases of the N low power PWM signals are made to be different from each other to make the on/off times of the semiconductor switching elements of the switching circuit to be different.
    Type: Application
    Filed: June 3, 2002
    Publication date: January 9, 2003
    Inventors: Choi Yeongha, Park Kyoungsoo, Sung Koeng-Mo