Leotek Electronics Corporation

Han-Jen Chuang

Chen-Ho Wu

Chen H Wu

A light emitting diode module for attaching to a surface of a sign, which includes a mounting plate having top and bottom surfaces, a plurality of light emitting diodes mounted to the top surface of the mounting plate, a housing having top and bottom surfaces, a first electrical connector attached to the bottom surface of the mounting plate and electrically connected to the plurality of light emitting diodes, a second electrical connector attached to the top surface of the housing for engaging with the first electrical connector, a third electrical connector attached to the housing and electrically connected to the second electrical connector, and a power supply for providing a voltage to the third electrical connector. As the bottom surface of the mounting plate is placed on the top surface of the housing, the first electrical connector engages with the second electrical connector for electrically connecting the plurality of light emitting diodes to the third electrical connector. Alternatively, the mounting plate could be integrally formed as part of the housing, and the first and second electrical connectors omitted.

Light emitting diode modules for illuminated signs

A circuit for driving a plurality of light emitting diodes (LEDs) that includes a power supply and a voltage divide circuit utilizing positive and negative temperature coefficient thermistors to boost the drive voltage to the LEDs as the ambient temperature deviates from room temperature, which compensates for increased electrical resistance of the LEDs at low temperatures and decreased LED light output efficiency at high temperatures. The circuit also provides a signal voltage to indicate the drive current through the LEDs, and includes a transistor to shut down the power supply when the signal voltage drops below a predetermined level (i.e. the number of burned out LEDs exceeds a predetermined number). A compensation circuit utilizes a thermistor to boost the signal voltage as the ambient temperature drops to compensate for the characteristic turn-on voltage of the transistor that increases as the temperature of the transistor drops.

Growing community of inventors

Kee-Lung, Taiwan

Han-Jen Chuang