A self-adjusting luminaire whose primary operation is to provide ambient or focused lighting in a hazardous environment is configured to modify (e.g., continuously) the energization intensity levels of its on-board illumination sources based on magnitudes of difference between an amount of light in the environment of the luminaire (e.g., including both light produced by the luminaire and ambient light) as measured by on-board sensors and a setpoint amount of light corresponding to the luminaire. Further, the self-adjusting luminaire may detect that its on-board sensors are malfunctioning when the illumination sensors fail to sense a change in the amount of light in the environment of the luminaire after the luminaire has modified the energization intensity levels of its illumination sources. Upon detecting a sensor malfunction, the self-adjusting luminaire may generate an alarm, and/or may automatically modify the intensity of its illumination sources to mitigate effects of the detected malfunction.

The present disclosure provides an LED straight light including a light tube with two pins at both ends, an LED installed in the light tube and a driving circuit. The driving circuit includes a mains branch and a signal branch. The mains branch is coupled to the pins at one end of the light tube for transmitting power to the LED for power supply. The signal branch is coupled to the pins at the other end of the light tube for transmitting external driving signals to control the on/off of the mains branch. The LED straight light of the present disclosure is powered by two ends, one of the two ends supplies power to the LED through the mains branch, and the other end receives driving signals to control the on/off of the mains branch.

A retrofit LED system for a lighting system allowing ease of replacement or installation of an LED lighting system in a grid ceiling. An adapter for providing easy installation of an LED lighting system within a room. A driver for operating directly from any standard AC voltage.

A lamp driver circuit for driving a lamp is provided. The lamp driver circuit includes: an under voltage protection circuit; a control circuit coupled to the under voltage protection circuit; and a driver transistor coupled to the control circuit for driving the lamp under the control of the control circuit. The under voltage protection circuit detects an operation voltage. When the operation voltage is lower than a threshold, the under voltage protection circuit outputs an enable signal. The control circuit receives the enable signal to shut down the control circuit and shut down the driver transistor.

A lamp driver circuit for driving a lamp is provided. The lamp driver circuit includes: an under voltage protection circuit; a control circuit coupled to the under voltage protection circuit; and a driver transistor coupled to the control circuit for driving the lamp under the control of the control circuit. The under voltage protection circuit detects an operation voltage. When the operation voltage is lower than a threshold, the under voltage protection circuit outputs an enable signal. The control circuit receives the enable signal to shut down the control circuit and shut down the driver transistor.

A method of overpower protection in a power supply system for driving a light source includes determining a voltage drop across a voltage-controlled resistor (VCR) coupled in series with the light source, calculating a power dissipation of the VCR based on the voltage drop and an output current of the power supply system, determining whether the power dissipation is greater than a power threshold, and in response to determining that the power dissipation is less than or equal to the power threshold, determining that an accumulated energy of the VCR is greater than zero, and decrementing the accumulated energy based on the power threshold and the power dissipation of the VCR.

A method of overpower protection in a power supply system for driving a light source includes determining a voltage drop across a voltage-controlled resistor (VCR) coupled in series with the light source, calculating a power dissipation of the VCR based on the voltage drop and an output current of the power supply system, determining whether the power dissipation is greater than a power threshold, and in response to determining that the power dissipation is less than or equal to the power threshold, determining that an accumulated energy of the VCR is greater than zero, and decrementing the accumulated energy based on the power threshold and the power dissipation of the VCR.

To promptly detect a failure of a light source. A vehicle headlight system includes a plurality of light sources, a power supply supplying a drive voltage to the light sources, a controller individually controlling a lit/off state of each light source, and a failure detection circuit connected to the controller and detects a failure of the light sources, where, in response to a start of the vehicle, the controller executes a control operation in which all light sources are controlled from the off state to the lit state and then the light sources are controlled to the off state sequentially and individually, and where, while the control operation is executed, at least during the period of transition from the off state to the lit state of each light source, the controller acquires failure detection result and generates a warning signal when the failure is detected.

To promptly detect a failure of a light source. A vehicle headlight system includes a plurality of light sources, a power supply supplying a drive voltage to the light sources, a controller individually controlling a lit/off state of each light source, and a failure detection circuit connected to the controller and detects a failure of the light sources, where, in response to a start of the vehicle, the controller executes a control operation in which all light sources are controlled from the off state to the lit state and then the light sources are controlled to the off state sequentially and individually, and where, while the control operation is executed, at least during the period of transition from the off state to the lit state of each light source, the controller acquires failure detection result and generates a warning signal when the failure is detected.

Embodiments of the present disclosure provide a backlight control circuit, a method for driving the same, a backlight module and a display apparatus. The backlight control circuit includes: an undervoltage protection circuit, electrically connected with a power supply voltage input end and a ground, and configured to output a closing control signal through an output end of the undervoltage protection circuit according to a voltage at the power supply voltage input end and an undervoltage threshold value; and a backlight driving circuit, electrically connected with a voltage supply end, a backlight driving output end and the output end of the undervoltage protection circuit separately, and configured to enable a port of the backlight driving circuit when receiving an enabling control signal for processing a voltage at the voltage supply end and outputting the processed voltage to the backlight driving output end, and stop working when receiving the closing control signal.