Design Of Automatic Laser Trimming Machine For Conductive Plastic Potentiometer

Conductive plastic potentiometer (CPP), a new type of high-precision potentiometer, is widely used in military industry, aeronautical and astronautical industry, auto industry, sophisticated manufacturing. The most important electrical parameter of CPP is its linearity, which can be improved by using automatic trimming machine that completes trimming process of CPP. This paper tries to explore automatic laser trimming technology considering the structure, function, trimming process of CPP and the requirements for the function trimming machine.Working principle of CPP is first introduced, followed by literature review of trimming technology for CPP at home and abroad, and the advantages of using laser technology for CPP are also elaborated. Subsequently, structural factors of CPP that influence the accuracy of the potentiometer are analyzed to determine trimming method. Overall plan of trimming for the system is designed according to the demands for system function, and precision requirements of each module are made through quantitative analysis on system precision.Given the characteristics of laser processing technology, mechanical structure of the system and electrical control module are devised following mechatronics technology. After that, mathematical model of resistor trimming is put forward, and optimization algorithm is then selected to design a powerful software module with user-friendly interface, completing the development of whole system.At last, this system is tested through experiments, the results of which indicate that such technology is able to significantly increase linearity of CPP. Conclusions are also drawn with prospect the future work presented.