The cascaded thermoelectric cooler driven by pulse width modulation method

Abstract

Thermoelectric coolers (TECs) work according to the Peltier effect. The effect produces a temperature difference by transferring heat between two electrical junctions. TECs are not only used in single mode but can also be in cascade. To drive or control the TECs, variable voltage or current circuits are needed. In this study, the TECs were simply controlled by the H-bridge driver, where the voltage applied to each TEC was modulated by the pulse width modulation (PWM) method. Three TECs were stacked each other. Each electrode is connected to the H-bridge drivers which are connected to the Arduino MEGA microcontroller. The result was that the PWM can effectively drive the cascaded TECs from a small PWM duty cycle. The performance of the cascaded TEC was studied, where the interface between TECs had temperatures far higher from the coolest side. Furthermore, the higher PWM duty cycles applied make temperature difference linearly higher. However, the temperatures of the modules were increased slowly by time and were relatively unstable.