Dual-Purpose Inductive Coil for Sensing and Charging
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Solution Overview
Problem
Existing input devices, such as proximity sensor devices, lack the ability to efficiently perform both inductive sensing and power transfer using a single coil, limiting their usability and functionality in electronic systems.
Innovation Solution
A dual-purpose coil is used in conjunction with a sensing circuit and a charging circuit, controlled by selection logic, to enable inductive sensing of materials like human tissue for attribute detection and power transfer from an external charging device, allowing the same coil to perform both functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single coil is used for both inductive sensing and power transfer, then device versatility is improved, but circuit complexity increases due to the need for selection logic and dual circuit coupling
Solution Approach 1:
The patent applies multi-functionality by designing a single coil that can serve dual purposes: inductive sensing and wireless power transfer. The selection logic circuit enables the coil to be dynamically coupled to either the sensing circuit or the charging circuit based on operational mode, allowing one physical component to perform multiple functions without requiring separate dedicated coils for each purpose.
Solution Approach 2:
The patent employs dynamic switching through selection logic that can couple the coil to different circuits based on operational requirements. The system transitions between sensing mode and charging mode by dynamically reconfiguring the coil's electrical connection, allowing the same physical coil to adapt its function based on real-time operational needs.
2Device complexity
If separate coils are used for sensing and charging, then circuit functionality is simplified, but device size and component count increase
Solution Approach 1:
The patent merges the sensing coil and charging coil into a single shared coil structure. By combining two previously separate components into one, the patent reduces the overall device footprint and component count while maintaining the ability to perform both inductive sensing and wireless power transfer functions through dynamic circuit switching.
Solution Approach 2:
The single coil is designed to be universal, capable of serving both sensing and charging functions. This multi-functional approach eliminates the need for separate dedicated coils, thereby reducing device size while maintaining complete functional capability for both operations.
3Reliability
If the coil is continuously coupled to both sensing and charging circuits, then system reliability is improved, but energy efficiency decreases due to simultaneous operation requirements
Solution Approach 1:
The system dynamically switches the coil's coupling between sensing and charging circuits based on operational mode. During sensing operations, the coil couples to the sensing circuit and disconnects from the charging circuit, and vice versa during charging operations. This dynamic reconfiguration ensures that only the necessary circuit is active, optimizing energy efficiency while maintaining system reliability through proper mode management.
Solution Approach 2:
The system employs periodic switching between sensing mode and charging mode operations. The selection logic circuit periodically reconfigures the coil's electrical connection based on the operational sequence, ensuring that the coil is coupled to the appropriate circuit at the appropriate time, thereby optimizing energy usage while maintaining reliable operation through structured operational cycles.
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 enhances usability by enabling the detection of user attributes like heartbeat and movement while also providing power to the device, improving the efficiency and versatility of electronic devices like smartwatches and smartphones.
Implementation Method 1
a sensing circuit configured to generate an oscillating electrical signal on the coil for performing inductive sensing
Implementation Method 2
a charging circuit configured to receive power from the coil while the coil is inductively coupled to an external charging device
Data Source
AI summary
Embodiments herein describe a user device that includes a dual purpose coil (or inductor) used when performing inductive sensing and when transferring electrical power to the user device. When performing inductive sensing, the user device couples the coil to a sensing circuit which measures a resistivity of a lossy material inductively coupled to the coil. In one embodiment, the user device may be worn on the wrist of the user so that the sensing circuit measures the resistivity corresponding to the flow of blood in an artery or vein. By monitoring changes in the resistivity of the blood or artery, the user device can identify the heartbeat of the user. When transferring electrical power, the user device couples the coil to a charging circuit which receives the power provided by an external charging device that is inductively coupled to the coil.