Ledvance Gmbh

Osram Gmbh

Shaoping Chen

Wei Tan

Shijun Nie

Yuli Chen

Jing Lin

Jin Hu

Xiongqiang He

Xusheng Yang

Hui Ye

ShiYu Ding

Huaming Chen

Junnan He

Luca Bordin

Fan Xin

Dandan Hou

Qingfu Zhang

Yandan Lin

A ripple reduction circuit for reducing a current ripple of a driver is provided. The driver circuit comprises an input section with input contacts for connecting the driver circuit to an AC power supply providing an AC input current and a power section for providing an output power, the power section comprising a power transformer and a power switch connected in series with a primary winding of the power transformer. The driver circuit further comprises a ripple reduction circuit with an inductance and a capacitive and two diodes, the ripple reduction circuit being configured such that, in operation, the inductance and the capacitance can be alternately charged and discharged, depending on the switching state of the power switch.

Driver circuit with reduced current ripple

A dynamic light control method for controlling at least one adjustable illumination parameter at a target location has been suggested. The method comprises setting the value of at least one adjustable illumination parameter at a first predetermined level, maintaining the value of the at least one adjustable illumination parameter at the first predetermined level for a first predetermined time period, varying the value of the at least one adjustable illumination parameter from the first predetermined level to a second predetermined level, maintaining the value of the at least one adjustable illumination parameter at the second level for a second predetermined time period, and varying the value of the at least one adjustable illumination parameter from the second level to a third predetermined level, wherein the varying the at least one adjustable illumination parameter comprises monotonously varying the at least one adjustable illumination parameter with a predefined maximum variation rate.

Dynamic light control method for controlling at least one illumination parameter

A lighting system comprises a primary luminaire and a secondary luminaire each having a light source. Electrical power can be transmitted wirelessly via an inductive wireless power transmission from the primary to the secondary luminaire. Electrical power can also be transmitted wirelessly via an RF wireless power transmission from a RF wireless power transmitter to both luminaires. Energy can be stored in energy storage means. Thus, true wireless lighting can be achieved.

Lighting system with wireless power supply

A boost power factor correction circuit, a driving circuit for light-emitting diodes and a lighting device are provided. The boost power factor correction circuit includes: a PFC controller; a PFC switch controlled by an output of the PFC controller; and an equivalent variable resistor connected between the PFC switch and the ground. A feedback current input of the PFC controller is connected to a node between the PFC switch and the equivalent variable resistor. The resistance of the equivalent variable resistor is controlled by the output voltage of the PFC circuit. In case that the PFC circuit operates under an mains AC or CCG input, the resistance keeps constantly minimum, and in case that the PFC circuit operates under an ECG input, the resistance increases as the output voltage of the PFC circuit decreases. The boost power factor correction circuit, the driving circuit for light-emitting diodes and the lighting device according to the present disclosure are able to be compatible with mains AC, CCG and ECG power supplies.

Boost power factor correction circuit, driving circuit for light-emitting diode and lighting device

The invention provides a driver circuit, an LED lighting tube and a method for providing a controlled DC output power. An open loop control is used for controlling the DC output power in the case that a voltage of an AC input power is in a first voltage range. A closed loop control is used for controlling the DC output power in the case that the voltage of the AC input power is in a second voltage range.

Driver circuit for an LED lighting tube, LED lighting tube and method for providing a controlled DC output power

A load drive circuit may include a DC power source configured to provide a DC output voltage for at least one load based on an output voltage of an AC/DC converter, the DC output voltage having a ripple, a variable resistance module connected to the load, a ripple reduction module that generates, based on a reference voltage and a feedback signal from the load, a variable resistance adjusting signal for adjusting the resistance of the variable resistance module so as to reduce a ripple of the load current, wherein the reference voltage is generated based on the DC output voltage, and a reference voltage adjusting module that adjusts the average value of the reference voltage based on the variable resistance adjusting signal, so as to make the average value of the reference voltage approach the average value of the feedback signal as much as possible.

Load drive circuit, load drive method, and luminaire

A dimmable LED driver adapted to be operated with a dimmer that is configured to generate a predetermined conductive angle, wherein the dimmable LED driver comprises: a rectifier configured to convert an alternating current output by the dimmer to a direct current, a buck PFC block configured to adjust an output voltage of the direct current so as to obtain a stable output voltage, a second buck DC/DC block configured to realize output of a constant current after the stable output voltage is realized, a dimming block configured to, after realizing output of the constant current, accomplish a dimming function jointly with the second buck DC/DC block, and an MCU configured to control the buck PFC block, the second buck DC/DC block and the dimming block.

Dimmable LED driver and method for controlling the same

The present invention relates to a control circuit for an illuminating device, characterized in that the control circuit comprises a detecting unit, a central control unit and an illumination mode control unit, the detecting unit detects ambient brightness and generates a detection signal, the central control unit controls the illumination mode control unit, according to the detection signal, to generate a plurality of first driving signal enabling the illuminating device to operate in a first illumination mode or a plurality of second driving signal enabling the illuminating device to operate in a second illumination mode. The control circuit can automatically adjust the illuminating device to be in different operation modes according to different ambient brightness.

Growing community of inventors

Guangdong, China

Shaoping Chen