A Measuring Method & System Studying On Characteristic Parameters Of Thermoelectric Module

With the improvement of the human environmental awareness and the difficult techniques of Semiconductor refrigeration have been overcome,Range of the thermoelectric module's applications becomes more and more widely.At present,testing instruments of thermoelectric module mostly monopolized by foreign equipment companies,the manufacturers of thermoelectric module unable to afford these expensive instruments in China,it's difficult to complete the inspections of thermoelectric module without these instruments.Therefore,it has important significance and practical value to develop a cheap testing system for thermoelectric module that can test characteristic parameters of thermoelectric module quickly and the method should be simple,the results should be reliable,the precision should meet the requirements of industrial production in China.The paper firstly analyzed the deficiencies of traditional testing methods in testing the characteristic parameters of thermoelectric module,the traditional testing methods have been optimized and improved by the paper.Which focuses on the testing methods of0 R and Z,In order to improving the accuracy of the test for0 R,the paper using the small AC power to driving the thermoelectric module.when testing the Z,the paper proposes a quick testing method of Z On the basis of derivation of heat balance equation on the hot and cold ends of thermoelectric module and the analysis of the characteristics of voltage when the constant current source driving the thermoelectric module.The paper applies STM32 as the core controller of the testing system.It also designs four important circuits that are constant current source circuit,inverter circuit,signal acquisition circuit and temperature acquisition circuit.The paper focuses on the design of constant current source circuit,by thecomparisons of different designs of constant current source,the paper chose the constant current source circuit based on the mechanism of current series negative feedback.On software,write the driver of STM32 for each module combined with hardware and using C# to write the PC program.Modules of the test system that may affect the test results have been tested,the paper also gifted the suggestions for improvement of each module;The precision,repeatability and stability of the test system has been tested,the errors of sources have been analyzed.The test results show that the testing system can quickly test the characteristic parameters of thermoelectric module,the precision,repeatability and stability of test system although has disparities compared with foreign advanced level,but basically meet the basic requirements of the manufacturers of thermoelectric module chip in China,it has some practical value.