Dual-Coil Eddy Current Sensing for Thermal Noise Reduction
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Solution Overview
Problem
Conventional eddy current induction sensing devices face measurement inaccuracies due to thermal effects and signal noise caused by coil temperature rise during long-term excitation, affecting resistance and inductance values and impairing measurement accuracy.
Innovation Solution
The method employs a dual-coil system where a first coil excites and a second coil receives electromagnetic signals, with the induced eddy current from the target conductor offsetting the second coil's signal, allowing for accurate measurement of the target conductor's state without thermal interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single coil is used for both excitation and reception functions, then device complexity is reduced, but measurement precision deteriorates due to thermal effects on the coil
Solution Approach 1:
The patent divides the single coil system into two separate coils: a first coil dedicated to excitation function and a second coil dedicated to reception function. This segmentation eliminates the thermal interference problem where the excitation current heats the coil and affects measurement accuracy, as each coil performs its specific function without being subjected to conflicting thermal and measurement demands.
Solution Approach 2:
The patent extracts the reception function from the excitation coil and assigns it to a separate second coil. By taking out the reception function, the system eliminates the harmful thermal effects that occur when the same coil is used for both excitation and reception, thereby improving measurement precision while maintaining relatively simple device structure.
2Adaptability or versatility
If the coil switches frequently between excitation and reception modes, then adaptability is improved, but measurement precision deteriorates due to signal noises from switching
Solution Approach 1:
The patent segments the excitation and reception functions into separate coils, allowing the system to operate in excitation mode or reception mode without needing to switch the same coil between modes. This eliminates switching-induced signal noises while maintaining the adaptability to perform different measurement tasks.
Solution Approach 2:
The first coil acts as an intermediary that generates the electromagnetic signal, which then induces eddy currents in the target conductor, which in turn affects the second coil's reception. This intermediary mechanism allows the system to maintain adaptability while avoiding direct mode switching of the reception coil, thereby preserving signal accuracy.
3Productivity
If high-power excitation is applied for long-term measurement, then productivity is improved, but measurement precision deteriorates due to significant temperature rise
Solution Approach 1:
The patent segments the excitation function (first coil) from the reception function (second coil), allowing high-power excitation to be applied continuously for long-term measurement without affecting measurement precision. The first coil can operate at high power to improve productivity, while the second coil remains thermally stable for accurate signal reception.
Solution Approach 2:
The patent extracts the reception function from the excitation coil, placing it in a separate second coil that is not subjected to high-power excitation. This allows the system to maintain high productivity through continuous high-power excitation while preserving measurement precision through the thermally stable reception coil.
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 approach reduces thermal effects on the second coil, enhancing measurement accuracy and signal-to-noise ratio by separating excitation and reception functions, thereby improving long-term measurement precision.
Implementation Method 1
generating a first electromagnetic signal, by the first coil, caused by the excitation signal
Implementation Method 2
generating an induced eddy current by a target conductor while the target conductor receives the first electromagnetic signal or the second electromagnetic signal
Data Source
AI summary
An eddy current induction sensing method includes: providing an excitation signal to a first coil; generating a first electromagnetic signal, by the first coil, caused by the excitation signal; coupling the first electromagnetic signal to a second coil to cause the second coil to generate a second electromagnetic signal; generating an induced eddy current by a target conductor while the target conductor receives the first electromagnetic signal or the second electromagnetic signal, wherein the induced eddy current at least partially offsets the second electromagnetic signal of the second coil; and measuring, from the second coil, a variation of the at least partially offset second electromagnetic signal to determine a state of the target conductor.