| 摘要 |
A dimmer circuit and a lighting apparatus using the same are provided. The dimmer circuit comprises a dimmer, a rectifier, a sample-and-hold unit, an integral unit and a current holding circuit. The dimmer is coupled to an AC for modulating the AC into an alternating signal. The rectifier couples the dimmer and the AC for rectifying the alternating signal into a DC signal. The sample-and-hold unit is coupled to the rectifier for sampling the DC signal to obtain an average positive wave pulse. The integral unit is coupled to the sample-and-hold unit for integrating the average positive wave pulse to generate a DC voltage. The current holding circuit comprises a switch and a bleeder. The current holding circuit determines the on/off state of the switch according to a comparison between the DC voltage and a reference voltage, such that the DC signal passes through the bleeder or the switch. |
