Shanghai Bright Power Semiconductor Co., Ltd.

Weijia Yu

Minmin Fan

Shungen Sun

Zhen Li

Shunfa Zhang

Wenkai Zhao

An LED dimming method, a dimming controller and system are disclosed. In a phase where a duty cycle of a PWM signal does not exceed a first threshold, every n periods of the PWM signal is taken as one set, taking a set as an output unit, and the duty cycle of the PWM signal is changed by incrementing or decrementing a average duty cycle by a first predetermined amount ΔP1 (0<ΔP1<0.2%), thereby adjusting an output current of an LED. In this way, the duty cycle of the PWM signal can be configured to increment by the first predetermined amount ΔP1 that is smaller than 0.2%. Moreover, when the first threshold is 10%, it can be ensured that each period of the PWM signal with duty cycle value within the range of 0-10% can be identified.

LED dimming method, dimming controller and system

A full voltage sampling circuit includes a main sampling circuit, an assist sampling circuit and a processing circuit. The main sampling circuit receives first and second input voltages, and outputs a first sampling signal according to the first and second input voltages. The first sampling signal represents a differential voltage which indicates a difference between the first input voltage and the second input voltage. The assist sampling circuit receives the first and second input voltages, and outputs a second sampling signal according to the first and second input voltages. The second sampling signal represents the differential voltage. The processing circuit is coupled to the main sampling circuit and the assist sampling circuit, and selects a larger one of currents or voltages of the first and second sampling signals as a sampling result to be outputted.

Full voltage sampling circuit, driving chip, LED driving circuit and sampling method

The present disclosure provides a leakage protection circuit, a method and a drive device. The leakage protection circuit is used for being electrically connected with the power supply line of a load, and may be configured to sample the power supply line at intervals, detect the voltage of the sampled electrical signals to determine whether the voltage of the AC input power is divided, and provide leakage protection based on the determined result. The present disclosure can prevent human from electric shock through sampling the electric signals from the power supply line at intervals and performing voltage detection and comparasion to determine whether the voltage of the accessed AC input power is divided, when the voltage of the accessed AC input power is determined to be divided, the power supply line will be controlled in non-conductive state.

Leakage protection circuit, method and drive device

The present disclosure provides a leakage protection circuit, a method and a drive device. The leakage protection circuit is used for being electrically connected with the power supply line of a load, and may be configured to sample the power supply line at intervals, detect the voltage of the sampled electrical signals to determine whether the voltage of the AC input power is divided, and provide leakage protection based on the determined result. The present disclosure can prevent human from electric shock through sampling the electric signals from the power supply line at intervals and performing voltage detection and comparison to determine whether the voltage of the accessed AC input power is divided, when the voltage of the accessed AC input power is determined to be divided, the power supply line will be controlled in non-conductive state.

Provided are a TRIAC dimmer detection circuit, chip and method, and an LED driving chip and system. A bus voltage reflecting signal is received, and a TRIAC dimmer detection signal is generated according to the bus voltage reflecting signal, a first reference voltage and a second reference voltage, the dimmer detection signal being used to detect whether a dimmer exists and to determine the type of the dimmer. The TRIAC dimmer detection circuit, chip and method, and the LED driving chip and system consistent with the present invention can detect whether a TRIAC dimmer is contained in an LED illuminating system, so as to determine a working state of a bleeder, thereby reducing the power consumption of the entire LED illuminating system and improving the efficiency thereof.

TRIAC dimmer detection circuit, chip and method, and LED driving chip and system

The present disclosure provides a line voltage compensation circuit, an LED drive system and a drive method. The line voltage compensation circuit is configured to receive signal reflecting bus voltage and output line voltage compensation signal based on the received signal reflecting bus voltage, a preset baseline voltage and at least one reference voltage, wherein the line voltage compensation signal has a multi-segment linear relationship with the received signal reflecting bus voltage. In the technical solution provided by the present application, the linear relationship between the feedback voltage of the LED load and the built-in baseline voltage is adjusted based on at least one preset threshold to output segment-based line voltage compensation signal. Compared with the line voltage compensation technology with a single slope, better input voltage line regulation and better LED current line regulation can be obtained by adopting the technical solution provided by the present application.

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Shanghai, China

Weijia Yu