Projeto e implementação de um conversor estático chaveado com fonte recarregável para alimentação de microfones condensadores

Abstract

Alongside the technological advance of mechanical wave transduction in electrical stimuli, the condenser microphones appeared. This microphone has a "capacitor" that receives the mechanical stimulus of the audio wave and changes its capacitance at each moment of the disturbance. In this way, a circuit polarization (approx. 48V) is required to generate an electric stimulus and then, transmit it to the sound mixer. The most popular way of feeding this device is the use of linear sources, due to the reliability and reduced incidence of noise provided by it. On the other hand, the existence of switching sources provides other option to replace the use of a linear source. The following work aims to provide a DC voltage to a condenser microphone using a 9 volt-battery, in addition to promote closed-loop control of the DC-DC converter (BOOST) used. In addition, it will be reviewed the mathematical modeling of the converter based on the two states of the switch operation to serve as reference in the design of the compensator. In this work, it will be also briefly approached the methods of control used and the auxiliary circuits that make up the prototype, as the instrumentation circuit, the driver circuit, the microcontroller and the decoupling capacitors.