Huizhou Light Engine Limited

Chung Ping Kevin Lo

Kam Wah Siu

Wa Hing Leung

Wa-Hing Leung

Kwok Hung Poon

Multiple LEDs connected in series are driven by DC voltage that is provided by a diode rectifier connected to a three-phase power source. In order to reduce ripple in the DC voltage, the series-connected LEDs can be divided into a first set and a second set, and a first constant current source is provided that drives the first set, and a second constant current source is provided that drives the second set. The first and second constant current sources are both connected across the outputs of the rectifier circuit, and operate to drive the respective sets of light emitting diodes in alternation. The capability for dimming can be provided, as well as back-up single phase operation. The light emitting diodes can be situated remote from said rectifier and connected thereto by a single phase power transmission system, formed by only two wires.

Method and arrangement for remotely driving light emitting diodes from a three-phase power source via a single phase cable system

Multiple LEDs connected in series are driven by DC voltage that is provided by a diode rectifier, the diode rectifier being connected to a three-phase power source and converting the three-phase currents from the three-phase power source into the DC voltage that is used to drive the light emitting diodes. In order to reduce ripple in the DC voltage, the series-connected light emitting diodes can be divided into a first set and a second set, and a first constant current source is provided that drives the first set, and a second constant current source is provided that drives the second set. The first and second constant current sources are both connected across the outputs of the rectifier circuit, and operate to drive the respective sets of light emitting diodes in alternation. The capability for dimming can be provided, as well as back-up single phase operation.

Method and circuit for driving light-emitting diodes from three-phase power source

A circuit for driving a light emitting diode (LED) comprises: an alternating voltage power supply, comprising a triac dimmer having a firing angle and output terminals that provide power to the LED; a zero crossing detector that detects a polarity change of the alternating voltage provided by the alternating voltage power supply and provides a zero crossing output signal indicative of the zero crossing; a timer triggered by the zero crossing output signal that generates a timer output signal during a time period of the timer; and LED power circuitry that reduces current to the light emitting diode based upon timing characteristics of the timer output signal.

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Hong Kong, China

Chung Ping Kevin Lo