Contactless Inductance Measurement via Impedance Insertion
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Solution Overview
Problem
Existing methods for determining the inductance of an oscillating circuit, particularly antenna coils in contactless data communication systems, are complex and time-consuming due to the need for galvanic connections and intricate measurement setups.
Innovation Solution
A method and device that introduce an additional impedance into the oscillating circuit temporarily, allowing for the determination of resonant circuit parameters which, when combined with known and unknown parameters, enable the calculation of inductance without direct contact, using relationships between modified and unmodified circuit parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If galvanic connection methods are used to determine inductance, then measurement accuracy can be maintained, but the measurement process becomes complex and time-consuming
Solution Approach 1:
The patent replaces galvanic (electrical contact) connection methods with electromagnetic induction-based contactless measurement. The test coil generates a magnetic field that induces voltage in the oscillating circuit under test, eliminating the need for physical electrical connections while maintaining measurement capability through inductive coupling.
Solution Approach 2:
The patent introduces a test coil as an intermediary element that mediates the measurement process. Instead of directly connecting measurement instruments to the oscillating circuit, the test coil acts as an intermediate medium that transfers energy and information through electromagnetic induction, simplifying the overall measurement setup.
2Measurement precision
If galvanic connection methods are used to determine inductance, then measurement accuracy can be maintained, but measurement time increases
Solution Approach 1:
The patent replaces galvanic (electrical contact) connection methods with electromagnetic induction-based contactless measurement. The test coil generates a magnetic field that induces voltage in the oscillating circuit under test, eliminating the need for physical electrical connections while maintaining measurement capability through inductive coupling.
Solution Approach 2:
The patent uses the natural oscillation characteristics of the circuit as the measurement signal source, eliminating the need for external signal generation and complex scanning procedures. By measuring the inherent resonant frequency and damping of the oscillating circuit, the method achieves quick results without preliminary signal setup.
3Measurement precision
If complex measurement setups are used, then inductance determination accuracy is improved, but ease of operation deteriorates
Solution Approach 1:
The patent replaces galvanic (electrical contact) connection methods with electromagnetic induction-based contactless measurement. The test coil generates a magnetic field that induces voltage in the oscillating circuit under test, eliminating the need for physical electrical connections while maintaining measurement capability through inductive coupling.
Solution Approach 2:
The patent uses the natural oscillation characteristics of the circuit itself as the measurement signal source. The oscillating circuit's inherent resonant frequency and damping properties provide the measurement information, eliminating the need for external signal generators, frequency scanners, or complex test equipment operation.
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
Enables efficient, quick, and cost-effective determination of inductance by simplifying the measurement process and eliminating the need for direct contact, thereby improving the speed and accuracy of inductance calculations in oscillating circuits.
Implementation Method 1
A magnetic field is generated by a single current pulse in the form of a Dirac surge
Implementation Method 2
An oscillation of the oscillating circuit in response to the excitation is detected
Implementation Method 3
a predetermined resonant circuit parameter of the resonant circuit modified by the introduction of the impedance is determined
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The method involves modifying resonant circuit by inserting (S1) additional impedance in resonant circuit. A predetermined parameter of modified resonant circuit is determined (S2) by introduction of impedance resonant circuit. The parameter of modified resonant circuit is provided in relationship with inductance of unmodified resonant circuit. The inductance of unmodified resonant circuit is determined (S3) based on specified parameter of modified resonant circuit and predetermined parameter of unmodified resonant circuit and introduced impedance. An independent claim is included for a testing apparatus for determining inductance of resonant circuit.