The Improvement Of PTCR Voltage Effect Testing System And Study On Its Anti-interference

PTCR has three main electronic characteristics which are R-T characteristic, V-I characteristic, I-T characteristic. V-I characteristic includes static V-I characteristic and Zero-power V-I characteristic which is called Voltage Effect. The determination of the main parameters of PTCR plays an important role in its application and research work. In this paper, we design a system, based on the previous work, realized auto-testing of the Voltage Effect.The system adopts PCI-1710HG card which is based on PCI local bus as the controller of peripheral equipment. The PCI-1710HG provides strong platform for the system. The pulse source is improved through extension of the hardware, auto-change circuit and filtering. Meanwhile it is easier to control. While focus on the large interference, wide signal range, we design a strong data acquisition module which has comprise four different resistors to adapt different signal, two different proportion to sample voltage of different range, difference input circuit to reduce interference and programmable gain amplifier for magnify faint signal. The design of alarm module and ability to show running state and mechanism design enhance security and reliability of the system. The anti-interference design is realized though isolation of different modules, shielding, filtering and ground design, which result in the limitation of interference.Software is programmed on the VC++ design platform. First, the main program and functional module of the software is consummated; Second, we design some modules include automatic range switch program, digital data processed program, multi-curve drawing program, auto-debug system which brings convenience to the user and realizes auto-functioning.In this dissertation, According to the relativity of PTC, the analysis of the processing data and the results of different testing condition including R-T curve, zero-power V-I curve and Voltage Effect curve brings significant meaning of the deep study of PTCR Voltage Effect.