The Design And Realization Of Power Signal Transmitter Module In NMR Logging Instrument

NMR logging tool utilizes the NMR principle to measure stratum porosity, and provides the compositive subsection of the stratum general porosity. The whole system includes three parts: signal transmitter, signal receiver, signal processor. This thesis expatiates part of the D series electronic circuit, viz. the transmitter circuit design method of generating high-power RF impulse, and actualize it.Based on understanding of the measure principle of NMR logging tool and the system working principle, the thesis analyzes the circuitry's design requirement, then seriously compares different methods which enhance the efficiency of power amplify circuit, including class-D and class-E amplifier, single-ended push-pull circuit, H-bridge power circuit, and finally chooses the design which based on H-bridge. Then, the thesis describes two important parts:power MOSFET driver circuit and full-bridge power amplifier, including material function, circuit design and circuit schematics which needs validation. Then the thesis gives relevant circuit realization and debugging report, including debugging progress of the scheduling pulse generation circuit and drive circuit, the experiment report of linear voltage incrementation experiment, 600V power supply voltage experiment and full-bridge circuit are also introduced.The greatest excellence of the high-power signal amplify circuit designed in this thesis in allusion to NMR Logging process is its small bulk, peripheral size approximately 50mm*50mm*1200mm. But its average power can up to 3~4KW, pulse voltage can up to 600V. It's suit of using in well exploration tool. The design has been fully tested by a series of experiment, the results of which validates efficiency of the scheme design based on the requirements of the NMR logging equipment.