Inductive Link Coil De-Tuning Compensation With Shield-Coupled Tuning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inductive power transfer and communication systems are susceptible to parasitic variations due to tissue and conductive surfaces, leading to reduced efficiency and increased stress on components, which are not compliant with regulatory requirements for fixed frequencies and require large, costly components.
Innovation Solution
A wireless coupling system with an electrostatic shield and variable impedance element, controlled by a control loop, to minimize impedance and adjust resonant frequency, using a variable inductor and voltage-controlled current source to stabilize the inductive link.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If frequency shifting or active re-tuning is used to address parasitic variations, then the inductive link efficiency is improved, but the system cannot operate at very fixed frequencies required by regulatory standards
Solution Approach 1:
The patent employs a control loop that continuously monitors the impedance of the inductive link and adjusts the resonant frequency in real-time to compensate for parasitic variations. This feedback mechanism maintains optimal power transfer efficiency while allowing the system to operate at fixed regulatory frequencies by dynamically adjusting other parameters to achieve compensation.
Solution Approach 2:
The system changes operating parameters (such as capacitance values or inductance values) to compensate for parasitic effects while maintaining the operating frequency at fixed regulatory values. This allows the system to adapt to varying conditions without violating frequency requirements.
2Power
If large currents and voltages are used in the coils, then power transfer capability is improved, but the size, cost, and stress on modulation and demodulation components increase
Solution Approach 1:
The patent introduces an intermediary coupling mechanism or impedance transformation stage between the high-power coil and the modulation/demodulation components. This intermediary allows high power transfer while protecting the sensitive modulation and demodulation components from direct exposure to large currents and voltages, thereby reducing their size and cost requirements.
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
The system enhances resistance to parasitic variations, reduces component stress, and maintains efficient power transfer and communication while complying with regulatory frequency requirements, using smaller and less costly components.
Implementation Method 1
an electrostatic shield for the first coil, wherein the electrostatic shield is inductively coupled to the first coil
Implementation Method 2
the core includes a material having, in a characteristic curve of relative permeability as a function of magnetic field intensity, a segment where the relative permeability of the material increases as the magnetic field intensity through the auxiliary coil increases
Implementation Method 3
a voltage controlled current source configured to generate the control current based on the control voltage
Data Source
AI summary
An inductive wireless power transfer and communication system includes an electrostatic shield for one of the coils. The electrostatic shield is inductively coupled with the coil and is configured as an open circuit. A signal processing element or elements, especially a modulator or a demodulator, are connected across the electrical discontinuity in the electrostatic shield. Because the electrostatic shield is inductively coupled to the coil, the modulator or demodulator can operate on the signal on the coil. An electronically controlled variable inductor is connected across the electrical discontinuity in the electrostatic shield. Because the electrostatic shield is inductively coupled to the coil, the variable inductor can tune the impedance of the system.