Dimming system and operating method thereof

摘要

A dimming system comprises a controller and an AC-to-DC converter. The controller outputs a control signal in response to a dimming signal. The controller comprises a frequency adjustment circuit and a duty cycle adjustment circuit. The frequency adjustment circuit adjusts the frequency of the control signal in response to the dimming signal. The duty cycle adjustment circuit adjusts the duty cycle of the control signal in response to the dimming signal. The AC-to-DC converter converts an external power and to output a DC signal in response to the control signal so as to drive a light source by the DC signal. When the controller is operated at a first mode, the control signal has a first frequency and a first duty cycle. When the controller switches to a second mode, the control signal has a second frequency and a second duty cycle.

主权项

1. A dimming system, comprising:
a controller, outputting a control signal in response to a dimming signal, comprising: a frequency adjustment circuit, adjusting the frequency of the control signal in response to the dimming signal; and a duty cycle adjustment circuit, adjusting the duty cycle of the control signal in response to the dimming signal; and an Alternating Current (AC)-to-Direct Current (DC) converter, converting an external power and generating a DC signal according to the control signal so as to drive a light source via the DC signal; wherein when the controller is operated at a first mode, the frequency of the control signal is a first frequency and the duty cycle of the control signal is a first duty cycle; when the controller switches to a second mode, the frequency of the control signal and the duty cycle of the control signal are simultaneously changed, the frequency of the control signal is changed to a second frequency and the duty cycle of the control signal is changed to a second duty cycle.