Now showing items 1-5 of 5

    • Adaptive on-time control for power factor correction stage light load efficiency 

      Virginia Tech Intellectual Properties, Inc.; Lee, Fred C.; Wang, Chung-Hsing Hsuan; Xu, Ming Gang; Li, Qian (United States Patent and Trademark Office, 2014-08-12)
      Light load efficiency of a power factor correction circuit is improved by adaptive on-time control and providing for selection between a continuous conduction mode and a discontinuous conduction mode wherein the discontinuous ...
    • Method and apparatus for automatic average current mode controlled power factor correction without input voltage sensing 

      SGS-Thomson Microelectronics S.R.L.; Virginia Tech Intellectual Properties, Inc.; Lee, Fred C.; Rajagopalan, Jayendar; Nora, Paolo (United States Patent and Trademark Office, 1999-07-06)
      A method for preparing power factor control integrated circuits which generate linear pulse width modulation (PWM) waveforms is presented. The method of pulse width modulation waveform generation involves providing a ...
    • Reducing common mode noise of power factor correction converters using general balance concept 

      Virginia Tech Intellectual Properties, Inc.; Lee, Fred C.; Wang, Shuo; Kong, Pengju (United States Patent and Trademark Office, 2010-09-28)
      Common mode (CM) noise is substantially canceled in a switching power supply circuit such as a boost converter by providing a split inductor and analyzing the switching power supply circuit as a bridge circuit formed of ...
    • Single-stage input current shaping technique with voltage-doubler rectifier front-end 

      Virginia Tech Intellectual Properties, Inc.; Delta Electronics, Inc.; Lee, Fred C.; Jovanovic, Milan M.; Huber, Laszlo; Zhang, Jindong Henry (United States Patent and Trademark Office, 2000-11-14)
      A single-stage input-current-shaping (S.sup.2 ICS) converter of the present invention integrates a voltage-doubler-rectifier front-end with a DC/DC output stage. Two families of voltage-doubler S.sup.2 ICS converters are ...
    • Universal system structure for low power adapters 

      Virginia Tech Intellectual Properties, Inc.; Li, Qiang; Lee, Fred C.; Huang, Xiucheng (United States Patent and Trademark Office, 2017-12-19)
      A two-stage power converter architecture including an isolation transformer and rectification of the isolation transformer output by an LLC resonant circuit and methodology for operating the same feeds an output voltage ...