Subdivided Differential Measurement Circuit for Wide Voltage Signals
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Solution Overview
Problem
Conventional measurement circuits struggle to accurately measure analog electrical signals with large voltage ranges due to limitations in component matching and accuracy, leading to errors in voltage division and dynamic settling.
Innovation Solution
The use of multiple measurement channels with differential inputs connected in series, combined through a summing circuit, which cancels out errors and allows for precise measurement of high-voltage signals by distributing the input voltage among channels, reducing the required accuracy of individual components and minimizing distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional single-channel ADC circuit is used to measure large voltage ranges, then the circuit structure remains simple, but measurement precision deteriorates due to component matching errors and limited voltage span
Solution Approach 1:
The patent divides the measurement system into multiple parallel measurement channels, each handling a portion of the total voltage range. Each channel includes its own ADC and input distribution network, allowing the system to measure large voltage spans by combining results from multiple smaller-range channels, thereby improving measurement precision without requiring a single high-range ADC
Solution Approach 2:
The patent combines multiple measurement channels in parallel, where each channel measures a segment of the input voltage. The digital outputs from multiple ADCs are summed to produce the final measurement result. This merging approach allows the system to achieve extended voltage range and improved accuracy by aggregating measurements from multiple channels
2Measurement precision
If voltage division is performed using conventional resistive dividers, then the circuit implementation is straightforward, but measurement precision deteriorates due to errors in voltage division and dynamic settling
Solution Approach 1:
The input distribution network is segmented into multiple parallel paths, each providing voltage division for a specific measurement channel. This segmentation allows each divider to operate within a smaller voltage range, reducing division errors and improving precision while maintaining relatively simple circuit implementation
Solution Approach 2:
The system employs digital correction based on calibration data stored in lookup tables. During operation, the measured values are corrected using pre-calibrated correction factors that compensate for voltage division errors, thereby improving measurement precision without requiring ultra-precise physical components
3Measurement precision
If high-precision component matching is used to improve measurement accuracy, then measurement precision improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The system performs self-calibration by measuring known reference voltages and storing correction factors in lookup tables. This self-service approach allows the system to compensate for component tolerances and mismatches automatically, achieving high measurement precision without requiring manually matched high-precision components
Solution Approach 2:
The system changes the operational parameters of each measurement channel to optimize performance. By adjusting reference voltages, gain settings, and correction factors based on calibration data, the system achieves improved measurement precision while using standard, easily manufactured components
Data Source
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AI summary
A measurement circuit comprises an electronic circuit, multiple measurement channels, and a combining circuit. The electronic circuit includes a first terminal, a second terminal, and a non-resistive circuit element. Each of the multiple measurement channels includes a differential input connected to the electronic circuit. The differential inputs of the multiple measurement channels are connected in series and include a differential input coupled to the non-resistive circuit element. One input of a differential input of a first measurement channel of the multiple measurement channels is connected to the first terminal of the electronic circuit and one input of a differential input of a second measurement channel of the multiple measurement channels is connected to the second terminal of the electronic circuit. The combining circuit receives multiple outputs from the multiple measurement channels and produce a composite output signal.