Patents by Inventor Siew E. Wong

Siew E. Wong 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).

  • Electronic ballasts
    Patent number: 5426344
    Abstract: A ballast circuit for fluorescent lamp which comprises an additional D2 located just after the rectifier bridge D1 and before smoothing capacitors C5, C6. The diode D2 is matched to the value of a mylar capacitor C3 connected across the output of the rectifier bridge and the fluorescent lamp load whereby the fluorescent lamp draws current over substantially the whole of the supply voltage waveform to thereby improve the power factor and reduce the current harmonic distortion.
    Type: Grant
    Filed: February 7, 1994
    Date of Patent: June 20, 1995
    Assignee: Ultralite International Pty Limited
    Inventors: Siew E. Wong, Thien S. Yang