Desenvolvimento de um sistema de aquecimento controlado: uma aplicação da pastilha de Peltier

Abstract

This work describes the development of a heating system, using the thermoelectric Peltier module as a heat source. The system consists of three main stages, the power electronic circuit, the control electronic circuit and the communication interface with the user. The power electronic circuit is responsible for electrically activating a Peltier module, which is composed of a DC-DC buck converter, which varies its output voltage from 2.7 V to 11.4 V according to the duty cycle that range from 20 % to 80 %. The converter is also composed of a bootstrap circuit, which supplies this MOSFET with a 25 kHz PWM signal from the unit control circuit. The communication interface has an LCD reader and the three cycle rate selection buttons. The complete designed system underwent the same test done with the DC-DC buck converter. The collected data were compared in order to verify if the designed system would be able to deliver the parameters operating targets. The voltage and current parameters were close to the desired ones, but the efficiency of the DC-DC buck converter reached the desired values only above 40% of the duty cycle of the PWM signal. The temperature of the Peltier tablet was also close to that measured using the bench function generator.