Patents Assigned to ADD Microtech Corp.
  • LED driving device
    Patent number: 6989807
    Abstract: A LED driving device includes a plurality of LEDs, a voltage detecting circuit, and a current switching circuit. When the voltage detecting circuit detects the different voltage level of power source without coupling to a filtering capacitor, it sends a signal to the current switching circuit and then the current switching circuit is automatically activated to electrically rearrange the configuration of LEDs with a predetermined current value by lighting the greatest number of LEDs that improving the power factor and efficiency.
    Type: Grant
    Filed: May 19, 2003
    Date of Patent: January 24, 2006
    Assignee: ADD Microtech Corp.
    Inventor: Johnson Chiang
  • LED driving device
    Publication number: 20040233145
    Abstract: A LED driving device includes a plurality of LEDs, a voltage detecting circuit, and a current switching circuit. When the voltage detecting circuit detects the different voltage level of power source without coupling to a filtering capacitor, it sends a signal to the current switching circuit and then the current switching circuit is automatically activated to electrically rearrange the configuration of LEDs with a predetermined current value by lighting the greatest number of LEDs that improving the power factor and efficiency.
    Type: Application
    Filed: May 19, 2003
    Publication date: November 25, 2004
    Applicant: ADD MICROTECH CORP.
    Inventor: Johnson Chiang