Fábio Vincenzi Romualdo da Silva

Proposal of a DC-DC converter with wide conversion range used in photovoltaic systems and utility power grid for the universal voltage range

This paper describes the design and implementation of a Boost connected in cascade with a Quadratic Buck converter, with just one active switch, used to drive a LED string for public and private lighting purposes. The proposed converter supports a wide input voltage range that makes it possible to be supplied from 12 VDC to 340 VDC (240 VAC), without any additional adjustment. It can be used in hybrid electrical systems supplied by photovoltaic systems or 110/220 VAC from the utility power grid. Experimental results from an 11 W prototype are also presented.

Class D power amplifier used as an electronic ballast

This paper presents a class D power amplifier used as an electronic ballast topology that can be used to supply one or more high pressure sodium lamps. It is ideal for poles luminaries with one or more High Pressure Sodium lamps used in private or public lighting. The proposed ballast supplies the lamps using synthesized waveform with fundamental frequency below 1 kHz in order to avoid acoustic resonance and minimize luminous flux oscillation. Control strategy, design guide line and experimental results are also included in this paper proposal.

Proposal of a dc-dc converter with wide conversion range used in photovoltaic systems and utility power grid for the universal voltage range

This paper describes the design and implementation of a Boost connected in cascade with a Quadratic Buck converter, with just one active switch, used to drive a LED string for public and private lighting purposes. The proposed converter supports a wide input voltage range that makes it possible to be supplied from 12 VDC to 340 VDC (240 VAC), without any additional adjustment. It can be used in hybrid electrical systems supplied by photovoltaic systems or 110/220 VAC from the utility power grid. Experimental results from an 11 W prototype are also presented.

Amplificador classe d para subwoofer

This paper proposal presents a high power Class-D audio amplifier for subwoofer applications with efficiency above 90%. A regulated dc voltage supply is not needed as well as a low pass output filter overcoming the disadvantages of ordinary Class-D audio amplifiers structures. A 1 kW laboratory prototype was implemented and it was found that efficiency above 90 % and THD below 1 % could be achieved. Detailed design guide lines, principle of operation analysis and control strategy are also included in this paper proposal.