Galvanically Isolated Probe for High-Accuracy Voltage Measurement
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Solution Overview
Problem
Existing oscilloscopes face limitations in accuracy and resolution for voltage measurements due to ground-referenced probes, which restrict the integration of digital multimeter (DMM) and digital voltmeter (DMV) capabilities, necessitating additional probes or reduced sensitivity.
Innovation Solution
A probe with a digital multimeter or voltmeter and an analog-to-digital converter, connected to a controller and communication interface, allows for galvanic isolation from earth ground, enabling high-accuracy, non-ground referenced measurements by communicating with an oscilloscope through a digital communication link, potentially using optical fibers for complete isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional ground-referenced oscilloscope probe is used, then the oscilloscope can provide visual time-domain measurement, but the voltage measurement accuracy and resolution are limited due to ground reference constraints
Solution Approach 1:
The system separates the high-accuracy DMM measurement function from the oscilloscope display function by placing the DMM in a galvanically isolated probe, allowing independent operation without ground reference constraints while maintaining oscilloscope visualization capabilities
Solution Approach 2:
A galvanically isolated communication interface acts as an intermediary between the isolated DMM probe and the ground-referenced oscilloscope, enabling data transfer while maintaining ground loop isolation and preserving measurement accuracy
2Adaptability or versatility
If DMM and DMV capabilities are integrated into the oscilloscope itself, then the device becomes more versatile, but the measurement accuracy is limited by the traditional ground-referenced probe connection
Solution Approach 1:
The system divides the measurement system into two independent parts: a galvanically isolated probe containing the DMM/DMV that achieves high measurement accuracy, and a ground-referenced oscilloscope that provides display and control functions, connected through isolated communication interfaces
Solution Approach 2:
Galvanically isolated communication interfaces serve as intermediaries that enable full functionality of both DMM and oscilloscope while maintaining ground loop isolation, allowing high-accuracy measurements without compromising system integration
3Measurement precision
If additional separate probes are used to achieve accurate voltage measurements, then measurement accuracy improves, but the device complexity and number of required components increases
Solution Approach 1:
The system merges the DMM/DMV measurement capabilities directly into the oscilloscope probe, creating a single integrated device that provides both high-accuracy voltage measurements and oscilloscope functionality through one probe connection rather than requiring multiple separate instruments
4Measurement precision
If galvanic isolation is implemented in the probe, then ground-loop elimination and measurement accuracy improve, but the communication complexity between probe and oscilloscope increases
Solution Approach 1:
Galvanically isolated communication interfaces act as intermediaries that enable data transfer between the isolated probe and ground-referenced oscilloscope while maintaining ground loop isolation, allowing high-accuracy measurements without compromising system integration
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables high-accuracy, non-ground referenced voltage measurements, eliminating ground-loops and enhancing signal fidelity, allowing for the use of a single probe to provide both digital and analog measurements with improved sensitivity and accuracy.
Implementation Method 1
The communication link between the probe and the oscilloscope may be implemented with an optical fiber to provide complete isolation from earth ground
Data Source
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AI summary
The disclosed technology relates to a probe for use with a test and measurement instrument. The probe includes a digital multimeter or voltmeter with an analog-to-digital converter configured to measure a signal from a device under test and determine a digital measurement from the signal, a controller connected to the multimeter or voltmeter configured to receive the digital measurement from the multimeter or voltmeter, a digital communication interface connected to the controller configured to communicate with the controller, and a communication link connected to the digital communication interface and the analog signal interface to communicate with the test and measurement instrument.