An LED lamp and it power source module are provided. The LED lamp includes an LED module and a power source module. The power source module includes two rectifying circuits, a filtering capacitor, a plurality of fuses, two filament-simulating circuits, and a discharge device. Each of the filament-simulating circuits is configured to allow a current to flow from one pin to the other pin via the corresponding first and second filament-simulating circuits during a pre-heat process executed by a ballast.

This application provides a constant-current drive circuit. First, the voltage at the input end is collected through peak-voltage sample and hold module to generate the input-voltage sampling signal, and the hold voltage at the current moment is obtained by calculating an average of the peak voltage of the input-voltage sampling signal and the hold voltage at the previous moment, and output as the output voltage signal to the voltage-controlled current source module. Then, a corresponding current signal is generated through the voltage-controlled current source module according to the output voltage signal and the preset second threshold voltage, and a mirror operation is performed on the current signal through the constant-current threshold control module to generate the mirrored current signal, and according to the mirrored current signal, the constant-current threshold is adjusted, so as to maintain the operation current flowing through the load a constant-current.

System and method for controlling one or more light emitting diodes. For example, the system for controlling one or more light emitting diodes includes a current regulation circuit coupled to a cathode of one or more light emitting diodes. The one or more light emitting diodes include the cathode and an anode configured to receive a rectified voltage. Additionally, the system includes a control circuit coupled to the cathode of the one or more light emitting diodes. The control circuit is configured to receive a first voltage from the cathode of the one or more light emitting diodes, compare a second voltage and a threshold voltage, and generate a control signal based at least in part on the second voltage and the threshold voltage. The second voltage indicates a magnitude of the first voltage.

A grounded voltage protection circuit for a linear drive circuit includes an AC-DC power supply module, a first voltage protection module, an LED module, a drive IC and a linear current adjustment module. Through the cooperation of the first voltage protection module, the drive IC and the linear current adjustment module, when a DC voltage signal output by the AC-DC power supply module exceeds a first preset voltage value, the first voltage protection module outputs the first preset voltage signal to prevent the drive IC and the LED module from being damaged due to the overvoltage output by the AC-DC module, and avoid the transient impulse voltage in the entire voltage protection circuit, thereby enabling the voltage protection circuit to pass the CEC certification.

An apparatus includes a controller (such as associated with a power converter). The controller is operative to receive input control settings. Based on the input control settings, the controller controls a magnitude of an output current generated by the power converter. The output current from the power converter powers light emitting hardware. The controller transitions between operating the power converter in an asynchronous mode and a synchronous mode to produce the output current.

A method for controlling a lighting system of a motor vehicle including a generator for generating a pulse-width modulated signal having a first peak intensity or a second peak intensity higher than the first peak intensity, and a light source. The method includes reception of an instruction to emit a light beam according to a given target luminous flux, selection of a peak intensity from the first and second peak intensities depending on the given target luminous flux. Also included is determination of a target duty cycle of a pulse-width modulated signal having the selected peak intensity depending on the given target luminous flux and the efficiency of the light source, and generation of a target signal having the selected peak intensity and the determined target duty cycle and provision of the target signal to the light source.

A method for controlling a lighting system of a motor vehicle including a generator for generating a pulse-width modulated signal having a first peak intensity or a second peak intensity higher than the first peak intensity, and a light source. The method includes reception of an instruction to emit a light beam according to a given target luminous flux, selection of a peak intensity from the first and second peak intensities depending on the given target luminous flux. Also included is determination of a target duty cycle of a pulse-width modulated signal having the selected peak intensity depending on the given target luminous flux and the efficiency of the light source, and generation of a target signal having the selected peak intensity and the determined target duty cycle and provision of the target signal to the light source.

A lighting control data generation method for generating lighting control data for controlling light sources in a HUD device includes: a measurement point specifying step for specifying measurement points in accordance with the brightness of light from a light source at each of output levels set to different values by a light source control unit which controls the light source with reference to lighting control data; and an output characteristic acquisition step for acquiring output characteristics by performing interpolation between the specified measurement points, wherein in the measurement point specification step, measurement points of a first specific point number are specified in a high-brightness mode in which the required brightness exceeds a threshold value, and measurement points of a second specific point number larger than the first specific point number are specified in a low-brightness mode in which the required brightness is the threshold value or low.

A system and method to determine a health status of a LED light string. The system (100) includes a circuit that includes a LED light string (110) and a pulsed current driver (115) of the LED light string. The circuit is connected to a power source (105). The system includes a current sensor (120) measuring a current through the circuit. The system includes a detecting device (130) determining a state of the circuit. The detecting device determines an expected current expected to be passing through the circuit where the expected current is associated with the state. The detecting device receives a current measurement from the current sensor during a time when the circuit is in the state. The detecting device determines a comparison between the current measurement and the expected current. The detecting device generates an output indicative of a health status of the circuit based on the comparison.

A light-emitting diode (LED) luminaire phase-dimming driver comprises a first power supply circuit, a second power supply circuit, and an interface control circuit. The second power supply circuit is configured to convert a constant voltage generated from the first power supply circuit into an output direct-current (DC) voltage to dim an external LED luminaire in response to a phase-dimming signal abstracted from a phase-cut mains voltage no matter whether the external LED luminaire is originally dimmable or not. The second power supply circuit is further configured to receive a pulse-width modulation (PWM) signal and to control the output DC voltage in response to the PWM signal. The interface control circuit comprises a relay switch configured to sense the phase-dimming signal and to control switching between an intermediate voltage and the output DC voltage to operate the external LED luminaire without flickering.