Wireless Power Feeder Resonance Control Circuit
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Solution Overview
Problem
Current wireless power feeding technologies, particularly the magnetic field resonance type, lack a mechanism for effectively controlling the magnitude of transmission power, leading to inefficiencies and increased costs due to the use of DC/DC converters which incur power loss.
Innovation Solution
A wireless power feeder system that includes a power transmission control circuit, a feeding coil circuit, a control signal generation circuit, and a comparison circuit to control the enable signal based on the relationship between control and reference signals, allowing for adjustable power transmission by varying the time ratio of power feeding and dormant periods, thereby minimizing power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a DC/DC converter is used to control transmission power magnitude, then power control capability is improved, but power loss increases by 10 to 20% and cost increases
Solution Approach 1:
The patent applies periodic action by controlling the power transmission in cyclic intervals through an enable signal that periodically activates and deactivates the power feeding. The control signal generation circuit generates a control signal with a control frequency lower than the resonance frequency, creating periodic on-off cycles that enable power magnitude control without using a DC/DC converter, thereby avoiding the 10-20% power loss associated with such converters.
Solution Approach 2:
The patent implements dynamics by making the power transmission state changeable between active and dormant periods through the enable signal. The comparison circuit dynamically adjusts the enable signal based on the relationship between the control signal level and reference signal level, allowing real-time power magnitude control without the energy losses inherent in static converter-based solutions.
2Ease of operation
If a DC/DC converter is used to control transmission power magnitude, then power control capability is improved, but device cost increases
Solution Approach 1:
The patent extracts the power control function from the traditional DC/DC converter approach and implements it through a simpler control signal generation circuit and comparison circuit. By taking out the complex converter mechanism and replacing it with signal processing circuits, the patent achieves power control capability while reducing device complexity and cost.
Solution Approach 2:
The patent substitutes the mechanical/electrical DC/DC converter system with an electronic control signal system. Instead of using a physical converter to adjust power magnitude, the patent uses electronic signal generation and comparison circuits to control power transmission timing, replacing a complex electromechanical system with a simpler electronic control system.
3Loss of energy
If time control method is used to adjust transmission power, then power loss is reduced, but control precision requirements increase
Solution Approach 1:
The patent implements feedback through the comparison circuit that continuously compares the control signal level with the reference signal level. This feedback mechanism ensures precise control by automatically adjusting the enable signal state based on the real-time relationship between signals, maintaining control precision without requiring excessively complex measurement systems while minimizing power loss through efficient time-based control.
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 precise control of transmission power in wireless power feeding systems, reducing power loss and costs by using time control methods, while maintaining high transmission efficiency.
Implementation Method 1
When the feeding coil generates a magnetic field to cause the feeding coil and receiving coil to magnetically resonate, large current flows in the receiving coil
Implementation Method 2
When AC power is fed to the exciting coil, current also flows in the feeding coil according to the principle of electromagnetic induction
Implementation Method 3
a feeding coil circuit that includes the feeding coil and a capacitor and resonates at the resonance frequency
Data Source
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AI summary
Power is fed from a feeding coil to a receiving coil by magnetic resonance. A drive circuit outputs an IN signal generated by an oscillator as a DR signal to alternately turn ON/OFF switching transistors at a resonance frequency, whereby AC current is fed to the feeding coil, and then the AC current is fed from the feeding coil to the receiving coil. An enable signal generation circuit generates an EN signal at a frequency lower than the resonance frequency. The drive circuit outputs the DR signal only while the EN signal assumes a high level. Transmission power from a wireless feeder to a wireless receiver is controlled by adjusting the duty ratio of the EN signal.