Patent classifications
H05B45/385
SOLID-STATE LIGHT EMITTER POWER SUPPLIES, DIMMABLE SOLID-STATE LIGHT SOURCES, AND METHOD OF POWERING SOLID-STATE LIGHT EMITTERS
A solid-state light emitter power supply includes a first rectifier circuit, a second rectifier circuit, a power factor correction (PFC) stage, a first flyback converter, a second flyback converter, and a microcontroller. The rectifier circuits are configured to receive phase-cut signals from respective dimmer circuits as inputs and output respective phase-cut rectified power signals. The PFC stage is configured to receive a sum of the phase-cut rectified power signals as input and output a power-factor corrected electrical power to the flyback converters. The flyback converters are connected in parallel and are configured to power respective loads including a respective solid-state light emitter. The microcontroller is configured to receive signals derived from the phase-cut signals as inputs and to output respective pulse-width modulation (PWM) control signals to each of the flyback converters. Each flyback converter receives a respective power output portion of the power-factor corrected electrical power in accordance with the respective PWM control signals.
Electronic device with adjustable illumination
This application discloses an electronic device (e.g., a camera) that a plurality of light sources and a light source driver. The light sources are configurable to a plurality of light source subsets to illuminate a field of view. At least two of the light source subsets include distinct light source members and are configured to illuminate different regions of the field of view. The light source driver is coupled to the plurality of light sources and configured to drive the plurality of light source subsets. In some embodiments, the electronic device includes or is coupled to a camera module configured to capture visual data of the field of view, and the plurality of light sources is configured to provide illumination for the camera module.
Electronic device with adjustable illumination
This application discloses an electronic device (e.g., a camera) that a plurality of light sources and a light source driver. The light sources are configurable to a plurality of light source subsets to illuminate a field of view. At least two of the light source subsets include distinct light source members and are configured to illuminate different regions of the field of view. The light source driver is coupled to the plurality of light sources and configured to drive the plurality of light source subsets. In some embodiments, the electronic device includes or is coupled to a camera module configured to capture visual data of the field of view, and the plurality of light sources is configured to provide illumination for the camera module.
Dimming control circuit, dimming control method and LED driver thereof
A dimming control circuit for an LED driver, can include: an adjusting circuit configured to generate an adjusting signal in accordance with a PWM dimming signal; and where a switching state of a power transistor of the LED driver is adjusted in accordance with the adjusting signal and a constant current control signal. A dimming control method for an LED driver, can include: determining a first threshold in accordance with a frequency of the PWM dimming signal and a frequency range of audio noise; generating an adjusting signal having a first duty cycle when a duty cycle of a PWM dimming signal is not greater than the first threshold; and controlling, by the adjusting signal, a switching state of a power transistor in the LED driver, where the first duty cycle is greater than the duty cycle of the PWM dimming signal.
Lighting module having field-replaceable optics, improved cooling, and tool-less mounting features
A lighting module includes a heat sink with a sidewall and a partition defining two cavities, a LED light source disposed in one cavity to emit light, a driver module disposed in the other cavity with driver circuitry to provide electrical power to the light source, and an optical assembly to provide a desired emission profile. The optical assembly is field-changeable and includes a cover lens with snap-fit connectors to facilitate removal and replacement. The optical assembly further includes either a reflector coupled to the cover lens or an optical lens coupled to the heat sink via an optic holder. In some examples, the driver circuitry facilitates dimming of the light source. The heat sink also dissipates heat generated by the light source and the driver circuitry to maintain desired operating temperatures and thereby facilitate increased light output.
AVERAGE CURRENT CONTROL CIRCUIT AND METHOD
A control circuit includes: a flip-flop having an output configured to be coupled to a control terminal of a transistor and for producing a first signal; a comparator having an output coupled to an input of the flip-flop, and first and second inputs for receiving first and second voltages, respectively; a transconductance amplifier having an input for receiving a sense voltage indicative of a current flowing through the transistor, and an output coupled to the first input of the comparator; a zero crossing detection (ZCD) circuit having an input configured to be coupled to a first current path terminal of the transistor and to an inductor, where the ZCD circuit is configured to detect a demagnetization time of the inductor and produce a third signal based on the detected demagnetization time; and a reference generator configured to generate the second voltage based on the first and third signals.
AVERAGE CURRENT CONTROL CIRCUIT AND METHOD
A control circuit includes: a flip-flop having an output configured to be coupled to a control terminal of a transistor and for producing a first signal; a comparator having an output coupled to an input of the flip-flop, and first and second inputs for receiving first and second voltages, respectively; a transconductance amplifier having an input for receiving a sense voltage indicative of a current flowing through the transistor, and an output coupled to the first input of the comparator; a zero crossing detection (ZCD) circuit having an input configured to be coupled to a first current path terminal of the transistor and to an inductor, where the ZCD circuit is configured to detect a demagnetization time of the inductor and produce a third signal based on the detected demagnetization time; and a reference generator configured to generate the second voltage based on the first and third signals.
TWO-STAGE POWER SUPPLY ARCHITECTURE WITH FLYBACK/LLC AND BUCK CONVERTER FOR LED DISPLAY
In an example, a system includes a single-output flyback/LLC converter adapted to be coupled to an alternating current (AC) power supply. The system also includes a buck regulator coupled to the single-output flyback/LLC converter. The system includes a first LED including an anode coupled to the single-output flyback/LLC converter and a cathode coupled to the buck regulator. The system also includes a second LED including an anode coupled to the single-output flyback/LLC converter and a cathode coupled to a ground terminal.
TWO-STAGE POWER SUPPLY ARCHITECTURE WITH FLYBACK/LLC AND BUCK CONVERTER FOR LED DISPLAY
In an example, a system includes a single-output flyback/LLC converter adapted to be coupled to an alternating current (AC) power supply. The system also includes a buck regulator coupled to the single-output flyback/LLC converter. The system includes a first LED including an anode coupled to the single-output flyback/LLC converter and a cathode coupled to the buck regulator. The system also includes a second LED including an anode coupled to the single-output flyback/LLC converter and a cathode coupled to a ground terminal.
Lighting apparatus
A lighting apparatus includes a light source, a rectifier circuit, a DC-DC converter, an adjustment circuit and a controller. The rectifier circuit converts an AC power to a raw direct current. The adjustment circuit provides an adjustment signal corresponding a light intensity setting of the light source. The controller is coupled to the DC-DC converter and the adjustment circuit. The controller receives the adjustment signal for generating a first PWM signal. The DC-DC converter receives the first PWM signal. The DC-DC converter converts the raw direct current to an output current according to a first duty ratio of the first PWM signal. The output current is supplied to the light source corresponding to the light intensity setting.