A Measuring System Studying On Characteristic Parameters Of Thermoelectric Cooler

With the increasing use of TEC(Thermoelectric cooler)in the field of temperature control,there are more and more low-end and mid-range chillers produced by TEC in the domestic market.At present,domestic TEC characteristic parameter testing instruments are mostly imported from abroad,and the price is very expensive.Most domestic TEC manufacturers are unable to purchase expensive imported instruments,and the lack of suitable TEC performance testing instruments has caused great problems for the quality inspection of these manufacturers.Therefore,the development of a test system that is cost-effective,stable in performance,accurate in meeting domestic industrial production requirements,and capable of quickly and reliably measuring various characteristic parameters of the TEC has important significance and application value for the development of the domestic semiconductor refrigeration industry.Based on the refrigeration principle of the TEC,the paper designs the measurement methods of different characteristic parameters,improves the measurement accuracy,and improves the measurement methods of device resistance and figure of merit.When measuring the resistance of the device,the paper use small current AC to drive the TEC to eliminate the influence of Seebeck effect.When measuring the coefficient of merit,a rapid measurement method is adopted.In the construction of the measurement system,the paper designs the system functional circuits using STM32 as the system controller.The key circuits are: programmable constant current source,signal acquisition and amplification circuit,temperature measurement circuit,H-bridge inverter circuit and so on.In this paper,a special temperature control device is designed,which can accurately control the temperature of the measured TEC and further improve the precision of the measurement system.The temperature control device adopts LADRC as a control strategy,and uses genetic algorithm in LADRC parameter tuning.In this paper,the measurement system is tested in modules,and the precision,stability and repeatability of the measurement system are verified.The experimental results show that the measurement system performs well in precision,stability and repeatability.The cost of the measuring device is far lower than the traditional measuring instrument,and the device is smaller in size and more convenient to operate.Although the test precision is still insufficient compared with the imported advanced instruments,it can basically meet the industrial production testing requirements and has some application prospects.