Abstract: An LED dimming method, a dimming controller and system are disclosed. In a phase where a duty cycle of a PWM signal does not exceed a first threshold, every n periods of the PWM signal is taken as one set, taking a set as an output unit, and the duty cycle of the PWM signal is changed by incrementing or decrementing a average duty cycle by a first predetermined amount ?P1 (0<?P1<0.2%), thereby adjusting an output current of an LED. In this way, the duty cycle of the PWM signal can be configured to increment by the first predetermined amount ?P1 that is smaller than 0.2%. Moreover, when the first threshold is 10%, it can be ensured that each period of the PWM signal with duty cycle value within the range of 0-10% can be identified.

Abstract: An interface control circuit, a control method and an interface control device. The interface control circuit is suitable for use in a dimming system compatible with both DALI dimming and push-button dimming. The interface control circuit includes a DALI signal reception control module having a first switch element. The DALI signal reception control module is configured to be enabled, upon a voltage at a power supply terminal of the interface control circuit reaching a pre-start voltage, to turn on or off the first switch element according to the magnitude of a voltage on a DALI bus. The pre-start voltage is lower than a start voltage of the interface control circuit. This invention can ensure accuracy and reliability of rapid communication reestablishment over a period of time from a power-off to the next power-on of the DALI bus.

Abstract: An LED dimming method, a dimming controller and system are disclosed. In a phase where a duty cycle of a PWM signal does not exceed a first threshold, every n periods of the PWM signal is taken as one set, taking a set as an output unit, and the duty cycle of the PWM signal is changed by incrementing or decrementing a average duty cycle by a first predetermined amount ?P1 (0<?P1<0.2%), thereby adjusting an output current of an LED. In this way, the duty cycle of the PWM signal can be configured to increment by the first predetermined amount ?P1 that is smaller than 0.2%. Moreover, when the first threshold is 10%, it can be ensured that each period of the PWM signal with duty cycle value within the range of 0-10% can be identified.