【摘要】 针对油基泥浆的不导电特点,采用Microchip公司生产的单片机PIC16F876和XILINX公司的CPLD XC9572设计实现了一种频率和幅度均可调的调幅波激励源。对于井下恶劣的环境和测井的不同需求,重点讨论了激励源的信号频率和幅度的调节以及对发射信号的实时监控方法。系统由控制电路、载波调制波获取电路、调幅波获取和电压检测电路组成。实验结果表明:激励源的调幅波频率和幅度可程控,信号发射稳定,带负载能力强,信噪比达到30dB。更多还原

【Abstract】 According to the non-conductive characteristics of oil-based mud,the authors design and implement AM wave excitation source whose frequency and amplitude can be adjusted by using SCM PIC16F876 from Microchip and CPLD XC9572 from XILINX.For the hostile environment of the underground and the different needs of the well logging,it emphatically discussed the adjustment method of the frequency and amplitude of the signal and the real-time monitoring method of transmitting signals.The system consists of control circuit,carrier and modulation wave acquisition circuit,amplitude modulation wave acquisition circuit and the voltage detection circuit.Finally,the experimental results show that the excitation source is stable with high load drive,its signal to noise ratio reaches 30 dB,and the frequency and amplitude of excitation signal are programmable.更多还原