DIGITAL EXCITATION SIGNAL GENERATOR FOR DOWNHOLE LOGGING TOOLS

摘要

A digital excitation signal generator can be used to modulate excitation current or voltage to be injected into a subterranean formation by a downhole logging tool. The digital excitation signal generator can include a processor and a pulse-width modulator ("PWM") device. The processor can generate a digital waveform and provide the digital waveform to the PWM device. The PWM device can convert the digital waveform into PWM pulses. The PWM device can be coupled to an interface. The interface can use the PWM pulses to modulate a voltage or current to be provided to an excitation electrode in the downhole logging tool. The digital excitation signal generator can also include a feedback module for maintaining a constant current output or constant voltage output to the excitation electrode.