The Development Of Current Recorder For The Modular High-Powered Down-Hole Transmitter System

The current recorder is a subsystem for the modular high-powered down-hole transmitter system, it’s designed for the accurate record of the current and voltage signal transmitted by the down-hole system, using both the 32 k Hz and 40 MHz sample rate. The 32 k Hz rate sample the wave form of current and voltage, the 40 MHz rate sample the edge, both with high accuracy, GPS synchronization technology, and low time drift. The current record sensor sampling signals in a contactless way, the operator can control the sampling procedure through the wireless network. The high-sample and low-sample speed data will be stored in the SD card, the files contains both the ADC data information and time information, for the needs of the later data processing.The system is designed to solve the problem of sampling large current and voltage signal, with GPS synchronization and low time drift. I have carried on the investigation to every module circuit and program evaluation. First the sensor is the precondition of system performance, it also can be high integrated and is safe. The ADC is produced by TI and ADI, they have a high performance, convenient design, and don’t need complex peripheral devices The control circuit adopts the combination of FPGA with the superiority of fast signal processing and ARM with rich on-chip interface resources, can save our design cycle, improve the performance of the system. The OCXO is designed as the main clock to provide stable and reliable clock source for the whole collection process for the time accuracy and low-time drift of data acquisition system.The final design of the recorder system is formed by front sensor, ADC sampling circuit, power circuit, clock circuit, FPGA and ARM core control circuit, the WIFI control module, interface circuit, and the Surface Pro hardware, the software is designed based on the MFC class library, control the procedure through the network communication, the recorder has been assembled and debugged, and achieved the basic performance test, completed the requirements of the system design.