An electronic AC power system with buck PFC and linear regulator to drive and control the current of power LEDs

This paper presents an electronic AC power system, with power factor correction, to drive and control the current of LEDs (Light Emitting Diodes). The power factor correction and the controlled DC bus voltage are performed by a Buck stage. A transistorized linear regulator coupled to the Buck will drive and control the LEDs. A study is presented considering the variation of the current ripple of LEDs as a function of the DC bus voltage ripple. A design methodology is presented for reducing losses in the linear regulator. Experimental results are presented to demonstrate the proposed design methodology.