The paper presents the results of an investigation was the general purpose of characterization and thermo-graphic evaluation electronic power semiconductor devices used in cyclo converters subjected to electric charges.To answer the question What is the thermal behavior of power electronic devices used for implementing a cycloconverter AC -DC and AC -AC, the framework of the cyclo converters AC -DC and AC -AC require power electronic devices such as diodes, transistors, and thyristors.These devices allow controlling current electrical power.Therefore it is necessary to characterize and evaluate the thermal performance of devices designed to show their behavior and thus determine the need for cooling systems to improve the energy efficiency of the system.The temperature of the power electronic devices, uncontrolled causes the device to become saturated causing damage to the intrinsic performance.Therefore by thermography technique, it is possible to characterize the behavior of the device and thus selecting a suitable option for heat dissipation.The methodology was divided into five phases and concluded that analyzes resulting from the application of the thermography technique indicated that the thermal behavior of the device is linear and not dependent on the type of load.