| 摘要 |
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. The duty cycle of the driving signal is adjusted based upon the compensation signal to adjust the average current flowing through the LED light source to the predetermined average current.
|
