Rotationally Offset Coil Pairs for Sensor Manufacturing Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensors for locating metal or magnetic objects face challenges due to manufacturing imprecision, which degrades the signal-noise ratio and requires additional adjustments, such as axis displacement, especially when coils are arranged as printed coils on a single circuit board.
Innovation Solution
The sensor employs two receiving subcoils with different inductances, achieved by varying the number of windings and the area enclosed by the windings, allowing for independent adjustment of manufacturing tolerances and electrical properties, eliminating the need for central axis displacement and ensuring identical amplitudes and phases of AC voltages in transmitting coils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the central axes of coil arrangements are displaced to adjust manufacturing tolerances, then manufacturing precision is improved, but the signal-noise ratio deteriorates
Solution Approach 1:
The patent applies local quality by making the receiving subcoils have different inductances through varying winding configurations (different numbers of windings, different areas, different average diameters). This localized differentiation allows each subcoil to be optimized for its specific position and function, compensating for manufacturing variations without requiring global displacement of coil axes, thereby maintaining signal-noise ratio while adjusting for manufacturing tolerances.
2Device complexity
If coils are arranged as printed coils on a single circuit board, then device complexity is reduced, but manufacturing precision deteriorates due to inability to displace central axes
Solution Approach 1:
The patent changes the inductance parameter of receiving subcoils by varying physical characteristics such as the number of windings, area enclosed by windings, and average diameter of windings. This parameter variation allows compensation for manufacturing tolerances in printed coil arrangements on a single circuit board, achieving precision adjustment without mechanical displacement of central axes.
3Adaptability or versatility
If transmitting coils have different ohmic resistance and inductance, then adaptability to manufacturing variations is improved, but device complexity increases due to non-identical amplitudes and phases
Solution Approach 1:
The patent applies homogeneity by making the transmitting coils have identical ohmic resistance and inductance within manufacturing tolerances. This ensures identical amplitudes and phases of AC voltages exciting the transmitting coils, simplifying the matching process. The homogeneity is achieved through symmetric design and identical winding configurations, allowing easy inductive and capacitive matching while still accommodating manufacturing variations through the inherent tolerance ranges.
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 design enhances the robustness of the sensor by maintaining signal quality and facilitating inductive and capacitive matching, while accommodating manufacturing variations without axis displacement, thus improving the sensor's accuracy and reliability.
Implementation Method 1
The transmitting coils and the receiving coil are inductively coupled to one another
Data Source
AI summary
A sensor for locating metal or magnetic objects includes a first and a second transmitting coil and one receiving coil. The receiving coil includes a first and a second receiving sub-coil. The first transmitting coil and the first receiving sub-coil are arranged in a first plane. The second transmitting coil and the second receiving sub-coil are arranged in a second plane. The first transmitting coil and the first receiving sub-coil are offset in relation to the second transmitting coil and the second receiving sub-coil with respect to a common center axis which passes vertically through the planes. The first receiving sub-coil is configured differently than the second receiving sub-coil.