| Popis: |
The cased hole resistivity logging technology is one of high-tech logging technologies being studied in China. The signal source requires high voltage, high current, ultra-low frequency, high stability, high resolution, etc. Based on the characteristics, proposed were the ideas that the direct digital synthesis technique should be applied to produce the required sine logging exciting signals, and high-power FET were used to produce the signals with high power and high voltage. The results show that the output frequency of signal source is 0~ 10 Hz, frequency resolution 0. 002 Hz, output voltage range -300 V~+300V, output current less than 6 A. The design has been successfully applied in the research project of extremely weak nV-level electric signal acquisition theory and experimental study on formation resistivity measurement through metal casing. |
