PTCR Multi-channel Comprehensive Parameters Test System Based On STM32

PTCR(Positive Temperature Coefficient of Resistance)is a kind of component or semiconductor material with large positive temperature coefficient.When the temperature exceeds a certain limit,its resistance value will increase rapidly.PTCR has been widely used in many fields,including delaying start,automatic degaussing,automatic keeping the temperature and so on.So its efficiency and reliability cause a high degree attention of the manufacturers.For producing eligible PTCR,it is necessary to test the performance of PTCR product.The traditional PTCR performance testing of voltage-withstanding cannot meet the needs of the factory.We also need to make aging characteristics test and measure the comprehensive parameters of PTCR to make a more accurate judgment of its quality.In this paper,the PTCR Multi-channel Comprehensive Parameters Test System Based on STM32 is designed,for making aging characteristics test and the comprehensive parameters measuring of PTCR automatically and in batches in the base of voltage-withstanding test.And the architecture,hardware design,software design are emphatically discussed.The hardware of the testing system consists of STM32 primary control board and STC secondary control board,overcurrent protection board.The STM32 primary control board realizes the control of STC secondary control boards through the RS-485.Through this way,the testing system can get the working status of the sample,the switching of reference voltage and sampling channel,the reading of overcurrent status,and the acquisition of data.So the testing system completes the job of voltage-withstanding test,aging characteristics test and the measure of the comprehensive parameters.The software of the system includes two parts,one is the STM32 and STC software,the other one is PC software.The STM32 and STC software is written by C language,which is very concise and understandable,and improving the efficiency of programming greatly.The PC software is written by C++ language.Using the Visual Studio C++ asdevelopment platform,which provides a very perfect application framework and strong class libraries.The data is received from the secondary machine through the RS-232 serial port,and the data is also processed methodically,such as display the curve,overcurrent status,each parameter and save the data.