Abstract:
A circuit for driving a light source includes a voltage converter, a switch and a controller. The voltage converter converts an AC input voltage signal to a first rectified AC voltage signal. The voltage converter further generates an average signal proportional to an average voltage level of the first rectified AC voltage signal. The switch is coupled to the light source in series. The controller coupled to the voltage converter and the switch compares the first rectified AC voltage signal with the average signal to generate a pulse signal. The controller further generates a dimming control signal based on the pulse signal to control the switch thereby controlling dimming of the light source.
Abstract:
A driving circuit for powering a light-emitting diode (LED) light source includes a converter circuit, an energy storage element and a switch element. The converter circuit provides a first output voltage on a first power line to provide power to the LED light source and provides a second output voltage on a second power line that is less than the first output voltage. The energy storage element is charged and discharged to regulate a current through the LED light source. The switch element operates in a first state during which the energy storage element is charged and operates in a second state during which the energy storage element is discharged. The converter circuit provides the second output voltage to maintain an operating voltage across the switch element less than the first output voltage during both the first state and the second state.
Abstract:
A method according to one embodiment may include providing power to at least one light source. The method of this embodiment may also include detecting the frequency of at least one vertical synchronization signal, among a plurality of different synchronization signals, and controlling the power to at least one light source based on, at least in part, the detected frequency of at least one vertical synchronization signal. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
Abstract:
A driving circuit for driving a light source includes a converter and a dimming controller. The converter coupled to a power source is operable for receiving power from the power source and for providing regulated power to the light source according to control signals. The dimming controller coupled to the converter is operable for monitoring a power switch coupled between the power source and the converter, for receiving a color change signal indicating a first set of operations of the power switch and a dimming request signal indicating a second set of operations of the power switch, for controlling the control signals to change the color of the light source in response to the color change signal, and for controlling the control signals to adjust the brightness of the light source in response to the dimming request signal.
Abstract:
A controller for controlling dimming of a light source includes a detection pin, an input signal pin, and a monitoring pin. The detection pin is operable for monitoring a rectified voltage and for detecting whether the rectified voltage comes from a TRIAC dimmer or an on/off switch dimmer. The input signal pin is operable for receiving an input signal indicative of the rectified voltage and the controller controls dimming of the light source according to the input signal if the rectified voltage comes from a TRIAC dimmer. The monitoring pin is operable for receiving a monitoring signal indicating an operation of the on/off switch dimmer and the controller controls dimming of the light source according to the monitoring signal if the rectified voltage comes from an on/off switch dimmer.
Abstract:
A controller for controlling dimming of a light source includes a detection pin, an input signal pin, and a monitoring pin. The detection pin is operable for monitoring a rectified voltage and for detecting whether the rectified voltage comes from a TRIAC dimmer or an on/off switch dimmer. The input signal pin is operable for receiving an input signal indicative of the rectified voltage and the controller controls dimming of the light source according to the input signal if the rectified voltage comes from a TRIAC dimmer. The monitoring pin is operable for receiving a monitoring signal indicating an operation of the on/off switch dimmer and the controller controls dimming of the light source according to the monitoring signal if the rectified voltage comes from an on/off switch dimmer.
Abstract:
There is provided a driving circuit for powering a plurality of light sources. The driving circuit includes a power converter, a plurality of switching regulators and a plurality of switching balance controllers. The power converter is operable for receiving an input voltage and for providing a regulated voltage to the light sources. The switching regulators are operable for adjusting forward voltages of the light sources respectively. The switching balance controllers are operable for generating pulse modulation signals to control the switching regulators respectively.
Abstract:
A method according to one embodiment may include supplying power to an LED array having at least a first string of LEDs and a second string of LEDs coupled in parallel, each of the strings includes at least two LEDs. The method of this embodiment may also include comparing a first feedback signal from the first string of LEDs and a second feedback signal from the second string of LEDs. The first feedback signal is proportional to current in said first string of LEDs and said second feedback signal is proportional to current in said second string of LEDs. The method of this embodiment may also include controlling a voltage drop of at least the first string of LEDs to adjust the current of the first string of LEDs relative to the second string of LEDs, based on, at least in part, the comparing of the first and second feedback signals. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
Abstract:
A circuit for driving a light source includes a voltage converter, a switch and a controller. The voltage converter converts an AC input voltage signal to a first rectified AC voltage signal. The voltage converter further generates an average signal proportional to an average voltage level of the first rectified AC voltage signal. The switch is coupled to the light source in series. The controller coupled to the voltage converter and the switch compares the first rectified AC voltage signal with the average signal to generate a pulse signal. The controller further generates a dimming control signal based on the pulse signal to control the switch thereby controlling dimming of the light source.
Abstract:
There is provided a driving circuit for controlling power of a light source. The driving circuit includes a power converter and a dimming controller. The power converter is coupled between a power source and the light source, and can receive power from the power source and provide a regulated power to the light source. The dimming controller is coupled to the power converter, and can receive a switch monitoring signal. The switch monitoring signal can indicate an operation of a power switch coupled between the power source and the driving circuit. The dimming controller is further operable for adjusting the regulated power from the power converter by controlling a switch coupled in series with the light source according to the switch monitoring signal.