Wireless Charging Alert via Coil Alignment Test Signals
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Solution Overview
Problem
Existing wireless power systems for charging electronic devices face inefficiencies in aligning wireless power coils, leading to unsatisfactory charging conditions, particularly when using removable battery cases with portable devices like cellular telephones.
Innovation Solution
A wireless power system that includes a first electronic device capable of receiving power from an AC-DC converter and transmitting test wireless power signals to a second device, which adjusts a ballast load to measure rectifier output voltage and compares it to a threshold, ensuring proper alignment and efficient power transfer before initiating charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wireless power systems wait for system initialization to complete before detecting charging status, then system stability is improved, but charging detection speed deteriorates
Solution Approach 1:
The patent performs coil alignment detection and charging status verification before initiating full wireless power transfer. The system conducts preliminary tests by transmitting low-power test signals and measuring rectifier output voltage to verify proper coil alignment and receiver readiness, ensuring reliable charging conditions are established before committing to full power transfer.
2Productivity
If wireless power systems transmit full power immediately upon device attachment, then productivity is improved, but power transfer efficiency deteriorates due to misalignment
Solution Approach 1:
The system performs preliminary coil alignment verification by transmitting test wireless power signals and measuring the rectifier output voltage at the receiver end. Only after confirming proper alignment through voltage threshold comparison does the system initiate full-power wireless charging, preventing energy waste from misaligned power transfer.
Solution Approach 2:
The system uses feedback from rectifier output voltage measurements to determine whether to proceed with full power transfer. The receiver measures the voltage across its rectifier during test signal reception and compares it to a threshold value, sending alignment status information back to the transmitter, which then decides whether to initiate efficient full-power charging.
3Loss of energy
If wireless power systems perform detailed alignment testing before charging, then power transfer efficiency is improved, but system complexity increases
Solution Approach 1:
The patent extracts the alignment verification function as a separate preliminary testing phase distinct from the main power transfer operation. The system isolates the alignment check by using low-power test signals and simple voltage threshold comparisons, separating this diagnostic function from the complex full-power wireless charging protocol to minimize overall system complexity.
Solution Approach 2:
The system uses disposable test signals - brief, low-power wireless transmissions solely for alignment verification - rather than committing to sustained high-power transfer until alignment is confirmed. These test signals are inexpensive in terms of energy and can be quickly transmitted and evaluated without complex prolonged testing sequences.
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 allows for early detection of coil alignment and efficient wireless power transfer, enabling rapid user notification of charging status and ensuring safe and effective battery charging without waiting for system initialization to complete.
Implementation Method 1
a first electronic device may receive power from an alternating-current-to-direct-current power converter. When power is being received in this way, the first electronic device has an opportunity to wirelessly transmit power to the second electronic device
Implementation Method 2
A magnetic sensor or other sensing circuitry may detect when the second electronic device is attached to the first electronic device
Data Source
AI summary
A wireless power system has first and second electronic devices. The first electronic device may receive power from an alternating-current-to-direct-current power converter. A magnetic sensor and/or other sensing circuitry may detect when a second electronic device is attached to the first electronic device. In response to detecting device attachment and receipt of power from the power converter, the first electronic device sends test wireless power signals to the second electronic device. During reception of the test signals, the second electronic device adjusts a ballast load so that output current from a rectifier in the second electronic device flows through the ballast load. The output of the rectifier is measured and compared to a threshold voltage. If the rectifier output voltage exceeds the threshold, the first electronic device is directed to alert the user that wireless charging of the second electronic device is commencing.