Signify Holding B.v.

Philips Lighting Holding B.v.

Shiguang Sun

Jie Fu

Zhiquan Chen

Marcus Cornelis Van Meel

Raimundo De Heer Galisteo

Gang Wang

Paul R Veldman

Dmytro Viktorovych Malyna

Yuanqiang Liu

Yu Wang

Zhi Quan Chen

Tijmen Cornelis Van Bodegraven

Simon Jacobus Maria Kuppens

Feng Ju

Liwen Zhou

Luna X Zhang

Yun Fei Duan

Yuangiang Liu

Gu Yuan Chen

Lyle Liu

Fan Zheng

To provide a safer over voltage protection, it is provided a driving circuit for a light emitting source, comprising an input adapted to receive a power supply; a conversion circuit, adapted to convert the power supply and provide a converted power, comprising a power switch (M); an output, adapted to output the converted power; an output capacitor (C) connected at the output; a first control circuit coupled to the output and connected to the power switch (M), adapted to sense a voltage corresponding to the voltage on the output capacitor and control the power switch operate in a power-reducing mode to reduce the converted power when the voltage corresponding to the voltage on the output capacitor sensed by the first control circuit exceeds a first level; and a second control circuit (D) connected to the output capacitor (C) and connected to a control terminal of the power switch (M), adapted to sense a voltage at the output capacitor (C) and damage and make the power switch (M) unoperational permanently when the voltage at the output capacitor (C) sensed by the second control circuit exceeds a second level.

LED driving circuit and LED lighting circuit

An LED driver that is operable with two different types of power source originally designed for a high-intensity discharge lamp. The LED driver directs current of an input power provided by the power source down a first current path if it is determined that the power source comprises a functional ignitor. The LED driver directs current of an input power provided by the power source down a second current path if it is determined that thepower source does not comprise a functional ignitor.

LED driver for LED lighting units for replacing a high-intensity discharge lamp

A device for determining a type of a power source for powering a LED lighting unit, wherein one possible type comprises a ballast originally designed for a high intensity discharge lamp and repurposed for use with an LED lighting unit. The power source type determiner monitors at least one electrical parameter of either a load or the power source itself after a power drawn by the load whose characteristic is set to a critical value. A value of the electrical parameter is used to identify a type of the power source. A value of the electrical parameter is the pulse generated by the traditional ballast for gas discharge lamp, which pulse is detected to determine the type of the power source.

Power source type determiner

A retrofit lamp is to be used with a ballast. A shunt switch is provided in parallel with an output load and is adapted to shunt input terminals of the lamp using pulse width control so as to tune the current through the lighting element. This current control is used to enable compatibility with different ballasts and to provide dimming control. A detection circuit is used to detect an abnormal drive condition of the retrofit lamp and the pulse width control of the shunt switch can then be overridden by holding the shunt switch at a stable state for a certain duration. This prevents overload conditions and avoids DC signals in the event of component failures.

Retrofit lamp and a lighting system using the same

An LED driver, comprising: an inductive switch mode converter having an inductive component (), an LED output () for an LED load and a main converter switch () for controlling a current flowing through the inductive component; a sensor () for generating a sensor signal indicative of the output current or voltage provided to the LED output; a feedback element () which provides a feedback path for feeding back the sensor signal for control of the main converter switch (); and a processing circuit () for processing the sensor signal which has been fed back, wherein the processing circuit is adapted to generate an output when there is no sensor signal so as to limit the current flowing through the main converter switch when no sensor signal is present.

LED driver and an LED driving method

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Shanghai, China

Shiguang Sun