Design Of Data Acquisition And Transmission System On High-Speed Changes Electric Field

In nature, engineering and scientific research, there are some high-speed changes the physical process. It is a great significance to collect and record the signals generated by these processes on the analysis of their formation mechanism and evolution. Lightning is a universal phenomenon in nature, it occurs often accompanied by strong light and sound effects. In lightning research, it is need to record the fast changes in the electric field when lightning occurs, and sometimes it needs multi-point simultaneous data acquisition for the analysis of the evolution process and the impact of various electronic products. For this demand, the paper designs a data acquisition system to conditioning and collect high-speed changes electric field signals when lightning occur, which can be used for outdoor multi-point simultaneous data acquisition.Lighting comes from the cumulonimbus, there is become the electronics field of breakdown the atmospheric, when the cumulonimbus amounts of certain electric charges. These electric fields are present in the atmosphere in the form of high-speed changes. In recent years, there are a lot of disasters occurrences on the ground for the acts of lighting, especially in the construction, electronics industries. Therefore, it is a great significance to record timely these high-speed electric signal changes for the study of the course of lighting discharge. The traditional method of high-speed data acquisition is mainly based on PCI high-speed data acquisition. However, this system has many shortcomings, such as large, expensive and interference. It can not be applied to multi-point simultaneous data acquisition in the field.The paper designs a high data acquisition system of small size, low power consumption. It consists of metal plate as the sensor system, ARM9(S3C2440) as a core control chip, using AD9248 to complete data acquisition. AD9248 is ADI company's dual-channel pipelined AD converter. It can be achieved fast and slow electric field synchronous data acquisition. The system storages and transmissions data by the USB interface and network interface, multi-point synchronization by GPS. It can be high-speed data acquisition and storage with 64MB memory.The design of system consists:the electric field sensor of high-speed changes, front-end signal conditioning circuit, high-speed A/D conversion, the main logic control, data storage and display modules. Electric field sensor is mainly used to sense the fast change signals when the lightning occurs; signal conditioning circuit is to complete analog signal amplifying and filtering to ensure adequate dynamic range; A/D converter circuit is mainly to convert analog signal to digital; logic control section is to complete the data acquisition and processing system, the synchronization control and other logic control; data storage module is timely to store in the U disk or send data through the network interface; display module is to complete the data or the resulting waveform display obtain the required results display the waveform.