Disclosed herein are systems and methods for powering light sources to reduce optical and/or electrical interference between the light sources and optical components in the same environment. The light sources may be powered using power modulation signals, whose frequency may be varied across modulation periods. Optionally, the frequency may be varied randomly or pseudo randomly. The systems and methods may additionally or alternatively introduce phase modulation into the control signals for driving channels of light sources. A phase difference in the control signals to at least two channels can reduce or avoid simultaneous or synchronous driving of the channels. The systems and methods described herein can vary one or more properties (e.g., frequency, phase shift, delay, duty cycle, power, etc.) of the power modulation signals.

The present disclosure provides apparatuses and methods for bulb detection for a lighting control system. The apparatus includes a lighting control module configured to cause a transmission of a quantity of electrical energy to a lighting circuit of a light fixture electrically connected to the lighting control module. The apparatus includes a detector circuit positioned in the lighting control module. The detector circuit is configured to measure a response of the lighting circuit to the transmission of the quantity of electrical energy. The apparatus also includes a controller in electrical communication with the detector circuit. The controller is specially programmed to correlate the quantity of electrical energy transmitted to the lighting circuit to the response of the lighting circuit. The controller is further programmed to determine the bulb type of a bulb electrically coupled to the lighting circuit of the light fixture.

A light projecting device may include an LED, an LED power supply, and a drive circuit. The LED emits light in a specific direction. The LED power supply supplies power to the LED. The drive circuit subjects the waveform of the drive current modulated at a specific frequency to DC offset and inputs the result to the LED.

A light projecting device may include an LED, an LED power supply, and a drive circuit. The LED emits light in a specific direction. The LED power supply supplies power to the LED. The drive circuit subjects the waveform of the drive current modulated at a specific frequency to DC offset and inputs the result to the LED.

LED drive control circuitry according to one embodiment outputs an LED drive control signal serving as driving a light emitting diode included in a photocoupler that performs insulation communication in synchronization with a reference clock signal. The LED drive control circuit includes a duty cycle changer that changes a duty cycle of the LED drive control signal in accordance with the reference clock signal and a signal synchronized with the reference clock signal.

LED drive control circuitry according to one embodiment outputs an LED drive control signal serving as driving a light emitting diode included in a photocoupler that performs insulation communication in synchronization with a reference clock signal. The LED drive control circuit includes a duty cycle changer that changes a duty cycle of the LED drive control signal in accordance with the reference clock signal and a signal synchronized with the reference clock signal.

A light source driving method is applied to a light source driving module electrically connected to a light source and a controller. The light source driving module includes a frequency setting module, a driving circuit, and a conversion module. The frequency setting module generates a frequency setting signal according to a switching signal. The driving circuit generates a light source driving signal after receiving the switching signal and a current control signal. The conversion module selectively generates a driving current flowing through the light source in response to the light source driving signal. The driving current increases continuously during a rising duration, and the light source driving signal has a first operating frequency during the rising period. The driving current remains unchanged during a stable duration, and the light source driving signal has a second operating frequency during the stable period.

A light source driving method is applied to a light source driving module electrically connected to a light source and a controller. The light source driving module includes a frequency setting module, a driving circuit, and a conversion module. The frequency setting module generates a frequency setting signal according to a switching signal. The driving circuit generates a light source driving signal after receiving the switching signal and a current control signal. The conversion module selectively generates a driving current flowing through the light source in response to the light source driving signal. The driving current increases continuously during a rising duration, and the light source driving signal has a first operating frequency during the rising period. The driving current remains unchanged during a stable duration, and the light source driving signal has a second operating frequency during the stable period.

An LED tube lamp includes a lamp tube receiving an external driving signal; a rectifying circuit rectifying the external driving signal to produce a rectified signal; a filtering circuit filtering the rectified signal to produce a filtered signal; an LED lighting module comprising a driving circuit and an LED module, the driving circuit, in a first driving mode, receiving the filtered signal to produce a first driving signal for driving the LED module to emit light; and a mode switching circuit receiving the filtered signal as a second driving signal in a second driving mode for driving the LED module to emit light. Wherein, the first driving mode and the second driving mode are determined based on the external driving signal.

The apparatus of a progressive direction indicator, especially for a car headlight or lamp, comprises the main connector (1) as the input electric interface, an LDM power supply module (2) for the power supply of the LED light sources (7), an LED board (4) where the LED light sources are mounted, and an interface (3) interconnecting the LDM power supply module with the LED board. The apparatus further comprises a current controller (9) for setting the current of the LED light sources, with the LDM power supply module comprising a DC/DC converter (5) generating the output voltage V out, which is the voltage source for the LED board. The LED board comprises discrete switching elements (8) for switching of individual LED light sources depending on the input voltage, so that the LED light sources are sequentially switched depending on the output voltage V out.