Light adjusting device with switching element

摘要

A light adjusting device for adjusting the luminance of a light source is provided. The light adjusting device comprises a rectifier module, a first switch element, a second switch element and a control module. The rectifier module receives an AC signal from a first power node and a second power node, and rectifies the AC signal to output a driving signal to the light source. The first switch element is coupled to the first power node. The second switch element is coupled to the second power node. The control module outputs a control signal to the first and second switch elements to control the conduction states of the first and second switch elements. When the first and second switch elements are turned on, the driving signal provided to the light source is interrupted.

主权项

1. A light adjusting device for rectifying the luminance of a light source, comprising:
a full-wave bridge rectifier for receiving an AC signal from a first power node and a second power node, and rectifying the AC signal to output a driving signal to the light source; a first switch element coupled to the first power node; a second switch element coupled to the second power node; and a pulse width modulation (PWM) signal generator for outputting a control signal to the first and second switch elements to control the conduction states of the first and second switch elements, wherein the first and second switch elements are turned off when the control signal is at a low level, and the first and second switch elements are turned on when the control signal is at a high level; wherein, when the first and second switch elements are turned on, the driving signal provided to the light source is interrupted; wherein one terminal of the full-wave bridge rectifier and one terminal of the light source are coupled to a common first node, the other terminal of the full-wave bridge rectifier and the other terminal of the light source are coupled to a common second node, the driving signal flows to the common second node from the common first node, and the first and second switch elements are coupled to the common second node.