Integrated micromachined electrostatic true RMS-to-DC converter

An integrated electrostatic true rms converter has been developed. It uses a compatible surface micromachining post-process, which combines the mechanical structure with standard electronic readout circuitry, thereby creating an integrated measurement system. The converter uses two identical bridge structures, which are capacitively driven. The system generates an rms voltage V/sub rms/, which forces the second bridge structure to give the same deflection as the one driven by the ac-input voltage. When a feedback loop is used, the converter can achieve a high accuracy. The converter features a high bandwidth compared to existing fully electronic converters and a very high input impedance compared to existing thermal converters.<
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