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 controller that monitors a rectified voltage and detects whether the rectified voltage comes from a TRIAC dimmer or an on/off switch dimmer is disclosed. The controller controls dimming of a light source according to the rectified voltage if the rectified voltage comes from the TRIAC dimmer. The controller controls dimming of the light source according to an operation of the on/off switch dimmer if the rectified voltage comes from the on/off switch dimmer.

Abstract: A circuit for driving a light-emitting diode (LED) light source includes a converter, a saw-tooth signal generator, and a controller. The converter includes a switch which is controlled by a driving signal. The converter provides a sense signal indicating the current through said LED light source. The saw-tooth signal generator generates a saw-tooth signal based on the driving signal. The controller generates the driving signal based on signals including the saw-tooth signal and the first sense signal to adjust the current through the LED light source to a target level and to correct a power factor of the driving circuit by controlling an average current of the input current to be substantially in phase with said input voltage.

Abstract: Embodiments of the invention provided a driving circuit for powering a light-emitting diode (LED) light source. The driving circuit includes a rectifier, a s filter capacitor, and a control circuit. The rectifier converts an AC voltage from an AC power source to a rectified AC voltage. The filter capacitor coupled to the rectifier filters the rectified AC voltage to provide a DC voltage. The control circuit controls power supplied to the LED light source. The control circuit enables a discharging current periodically to discharge the filter capacitor if a switch coupled between an AC power source and a rectifier is turned off and disables the discharging current if the control circuit determines that the switch is turned on.

Abstract: Embodiments in accordance with the present invention provide circuits and methods for driving light sources, e.g., a light-emitting diode (LED) light source. In one embodiment, a lamp includes a rectifier rectifying an AC voltage to a rectified AC voltage, an LED light source, and a switch coupled to the LED light source in series controlling a current through the LED light source according to a predetermined current reference. The LED light source and the switch coupled in series receive the rectified AC voltage while the switch is controlled linearly.

Abstract: A controller for controlling dimming of a light-emitting diode (LED) light source includes a switch monitoring pin, a current monitoring pin, and a control pin. The switch monitoring pin monitors an operation of a power switch which transfers an AC voltage to a rectifier when the power switch is on. The current monitoring pin receives a current monitoring signal indicating a current flowing through the LED light source. The control pin generates a control signal to control a second switch coupled in series with the LED light source to adjust the brightness of the LED light source according to the operation of the power switch.

Abstract: A circuit for driving a light source, e.g., an LED light source, includes a converter, a sensor, and a controller. The converter converts an input voltage to an output voltage across the LED light source based upon a driving signal. A duty cycle of the driving signal determines an average current flowing through the LED light source. The sensor is selectively coupled to and decoupled from the converter based upon the driving signal. The sensor generates a sense voltage indicative of a current flowing through the LED light source when the sensor is coupled to the converter. The controller is coupled to the converter and sensor. The controller compares the sense voltage to a reference voltage indicative of a predetermined average current through the LED light source to generate a compensation signal and generates the driving signal based upon the compensation signal.

Abstract: A differential driving circuit for powering a light source is disclosed. The differential driving circuit includes a first set of switches and a second set of switches. A first current from a power source flows through the first set of switches to charge a first energy storage element when the first set of switches are turned on. A second current from the first energy storage element flows through the second set of switches to power the light source when the second set of switches are turned on. The differential driving circuit further includes a second energy storage element coupled to the light source in parallel and for providing a differential voltage to the light source.

Abstract: A circuit for driving a load includes a power line, converter circuitry, and a controller. The power line is operable for providing an input current and an input voltage. The converter circuitry coupled to the power line is operable for converting the input voltage to a regulated voltage to drive the load, and for providing a current detection signal indicating whether a converter current flowing through the converter circuitry drops to a predetermined level. The controller coupled to the converter circuitry is operable for correcting a power factor of the circuit based on the current detection signal and the input voltage such that a waveform of the input current follows a waveform of the input voltage.

Abstract: A driving circuit for controlling a light source includes a frequency controller and a switch module. The frequency controller is operable for receiving a first dimming signal for controlling the light source to achieve a predetermined brightness, and for generating a second dimming signal having a frequency out of one or more predetermined ranges according to the first dimming signal when the frequency of the first dimming signal is within the predetermined ranges. The switch module coupled to the frequency controller is operable for switching on and off alternately to achieve the predetermined brightness of the light source according to the second dimming signal when the frequency of the first dimming signal is within the predetermined ranges and according to the first dimming signal when the frequency of the first dimming signal is out of the predetermined ranges.

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 light source driving circuit for powering multiple light sources in a vehicle includes multiple current limiters and a balance controller. The current limiters are coupled to the light sources for adjusting currents of the light sources respectively. The balance controller coupled to the current limiters can control the current limiters such that a current flowing through each of the light sources is substantially the same as a first target current. Moreover, the balance controller can control the current limiters in response to a brake of the vehicle such that a current flowing through each of the light sources is substantially the same as a second target current.

Abstract: A driving circuit for controlling power of a light source includes a power converter coupled to a power source and the light source, and a dimming controller coupled to the power converter. The power converter can receive power from the power source and provide a regulated power to the light source. The power converter includes a control switch coupled in series with the light source. The dimming controller can monitor a power switch coupled between the power source and the driving circuit, and receive a dimming request signal and a dimming termination signal. The dimming request signal can indicate a first set of operations of the power switch. The dimming termination signal can indicate a second set of operations of the power switch.

Abstract: A dimming controller for controlling dimming of a light-emitting diode (LED) light source includes a monitoring terminal and a control terminal. The monitoring terminal receives a switch monitoring signal indicative of an operation of a power switch which transfers power from an AC power source to a bridge rectifier when the power switch is on. A power converter receives input power from the bridge rectifier and provides output power to the LED light source. The control terminal generates a control signal to adjust the output power according to the switch monitoring signal so as to control dimming of the LED light source.

Abstract: Coumarin compounds of formula (I): wherein R1, R2, R3, R4, R5, R6, and X are defined herein. Also disclosed is a method for treating cancer with coumarin compounds.

Abstract: An electric door lock including: a lock housing; an operating member having a holding part and a shaft part, the shaft part able to be placed in the lock housing, the shaft part connected to the holding part, the holding part defined as a long axis; a cog wheel able to be placed in the lock housing, the cog wheel having at least one bump; a coupling plate installed on the shaft part of the operating member, the coupling plate having at least one bulge and one protruding part, with the protruding part and the long axis of the holding part designed to move in alignment with each other; a motor placed in the lock housing; three sensor switches set separately in the lock housing; operating the motor causing the bump of the cog wheel to rotate and push the bulge of the coupling plate, so that the protruding part of the coupling plate of the electric door lock installed in the required position on a left-hand door or right-hand door, selectively touches the two sensor switches adjacent to each other, so as to reach

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.

Abstract: A controller for controlling dimming of a light-emitting diode (LED) light source provides a pulse signal by comparing a sensing signal indicative of a current flowing through the LED light source to a reference signal. The controller controls the current through the LED light source according to the pulse signal during a first state of a pulse-width modulation signal and cutting off the current through the LED light source during a second state of the pulse-width modulation signal. The controller receives a dimming request signal indicative of an operation of a power switch coupled between an AC power source and a bridge rectifier and adjusts both a level of the reference signal and a duty cycle of the pulse-width modulation signal based on the dimming request signal.

Abstract: A controller for controlling dimming of an LED light source includes a control terminal and dimming control circuitry coupled to the control terminal. The control terminal provides a driving signal to control a control switch coupled to the LED light source, thereby controlling the dimming of the LED light source. The dimming control circuitry generates the driving signal according to a set of operations of a power switch that transfers an AC signal. The dimming control circuitry further adjusts the driving signal by counting multiple waves of the AC signal to control the dimming of the LED light source.