A new double frequency dimmer for lighting device

This paper proposes a new double frequency dimmer for lighting devices, especially for fluorescent lamps and light-emitting diodes (LEDs). Compared with the conventional phase-controlled TRIAC dimmer, dummy load or bleeder resistor is not required in the new double frequency dimmer, moreover, there is no R-C delay circuit in the proposed dimmer, and hence, some lighting flicker phenomena caused by the R-C delay circuit can be avoided. The biggest feature of the proposed dimmer is that the frequency of the output of the dimmer is twice than that of the TRIAC dimmer, which will eliminate the lighting flicker caused by line frequency operation in some cases and may filer capacitor requirement of the AC/DC converter.