Research And Development Of The Semiconductor TEC Test System

Semiconductor cooler is used of the Seebeck effect and the Peltier effect. Compared with the traditional refrigeration modes, it has no pollution, no noise, cooling and heating state reversible characteristics. In a lot of electronic equipment and engineering applications, temperature is an important factor to affect their work performance. So a efficient device to control the temperature is becoming a hot spot developed by the refrigeration industry. In this paper, the design of semiconductor TEC parameter test system is based on the theoretical basis of the TEC cooling technology. It’s for testing and evaluating of parameters characteristic of the TEC components.At first, the paper analysis of the working principle of the semiconductor TEC cooler, then proposed the TEC relevant performance parameters’derivation algorithm. The relevant parameters include:the device resistance R, the figure of merit Z, the maximum temperature difference ΔTmax and the parameters of maximum operating condition and so on. Then, according to the various parameters’associated algorithm,the paper designed a test program. The program mainly includes:the H-bridge drive circuit module,the circuit module of the constant current source, the acquisition signal amplifying circuit module, the microprocessor control module. Then combined with the actual test accuracy and used the hardware simulation to determine the various parts of the device in the circuit.Then, accoring to the design of the various test parameters of the algorithm derivation,the paper write the STM32processor drivers. The drivers mainly include:the DAC,the ADC,the PWM module and data algorithms solving various parameters. In this part,the DAC used to control the work of the current source circuit module;the PWM used to control the work of the H-bridge circuit module;the12-bit ADC used to acquisite the signal. Using RS232communication interface, paper realized the computer communication with the equipment. It allows the test system is more practical.The design of the subject than the traditional method of testing has the following advantages:First, using a program of micro-current and alternating to test the resistance of the device, it minimize interference of the thermal electromotive force. The second point is that used the multi-stage operational amplifier processing, which could improved weak signal testing accuracy. The third is add the efficient derivation of data processing algorithms to improve the accuracy of the test results. System by designed have completed the testing of the main parameters of the TEC, and the paper analysis of the test results of the system.Test result show than the TEC component resistor R measurement error is less than0.02ohm, the maximum temperature difference ΔTmax measurement error is less than1.0℃. Other parameters through the algorithm derivation,errors are within3%.