Inductive Power Supply Duty Cycle Control Resonance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wireless power supply systems face challenges in maintaining high power transfer efficiency due to the need for precise alignment and specific design of inductive power supplies and remote devices, as well as inefficiencies when adjusting operating frequencies or using fixed frequencies with adjusted rail voltages, duty cycles, or phases.

Innovation Solution

An inductive power supply system that maintains resonance and adjusts the duty cycle based on feedback from a secondary circuit, using a primary controller, driver circuit, and switching circuit to generate an AC signal at a selected frequency and duty cycle, optimizing power transfer efficiency by continuously adjusting the operating frequency and duty cycle to ensure efficient power delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the operating frequency is adjusted closer to or further from resonance to control power delivery, then the amount of power delivered to the remote device can be increased or decreased, but the power transfer efficiency decreases

Engineering Contradiction:
Improveamount of power deliveredVSAvoidpower transfer efficiency
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the duty cycle adjustable and variable during operation. The controller dynamically changes the duty cycle of the AC signal across the tank circuit to control power delivery while maintaining resonance, allowing the system to adapt power output without sacrificing efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter being controlled from frequency to duty cycle. Instead of adjusting operating frequency to control power (which reduces efficiency), the system maintains fixed resonance frequency and controls power delivery by varying the duty cycle parameter, thereby achieving both power control and high efficiency.

Inventive Principle:
Principle #35Parameter changes

2Power

If a fixed operating frequency is used and rail voltage or duty cycle is adjusted to control power delivery, then power delivery can be controlled, but precise alignment and specific design are required to maintain acceptable power transfer efficiency

Engineering Contradiction:
Improveamount of power deliveredVSAvoidalignment and design requirements
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent implements feedback by using a secondary circuit that communicates information back to the primary controller. This feedback mechanism allows the system to automatically adjust and optimize performance without requiring precise manual alignment or complex design matching between primary and secondary circuits, thereby reducing device complexity requirements.

Inventive Principle:
Principle #23Feedback

3Power

If the resonant frequency of the tank circuit is adjusted closer to or further from the operating frequency to control power, then power delivery can be controlled, but power transfer efficiency decreases

Engineering Contradiction:
Improveamount of power deliveredVSAvoidpower transfer efficiency
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the duty cycle adjustable and variable during operation. The controller dynamically changes the duty cycle of the AC signal across the tank circuit to control power delivery while maintaining resonance, allowing the system to adapt power output without sacrificing efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter being controlled from frequency to duty cycle. Instead of adjusting operating frequency to control power (which reduces efficiency), the system maintains fixed resonance frequency and controls power delivery by varying the duty cycle parameter, thereby achieving both power control and high efficiency.

Inventive Principle:
Principle #35Parameter changes

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 approach allows for high-efficiency wireless power transfer while maintaining resonance, providing fine-tuned control over the amount of power delivered, reducing overall losses, and easily meeting specified power requirements, even with varying conditions.

Implementation Method 1

The controller, driver circuit and switching circuit cooperate to generate an AC signal at a selected operating frequency and duty cycle. The AC signal is applied to the tank circuit to create an inductive field for powering the secondary.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The present invention provides an inductive power supply that maintains resonance and adjusts duty cycle based on feedback from a secondary circuit.

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP2232669B1Inductive power supply with duty cycle control
Publication Date: 2019.12.04 PHILIPS IP VENTURES BV
  • EP2232669B1 patent drawingFigure 1
  • EP2232669B1 patent drawingFigure 2
  • EP2232669B1 patent drawingFigure 3A

AI summary

An inductive power supply (100) that maintains resonance and adjusts duty cycle based on feedback from a secondary circuit. A controller (110), driver circuit (111) and switching circuit (115) cooperate to generate an AC signal at a selected operating frequency and duty cycle. The AC signal is applied to the tank circuit (120) to create an inductive field for powering the secondary..The secondary communicates feedback about the received power back to the primary controller (110). The power transfer efficiency may be optimized by maintaining the operating frequency substantially at resonance, and the amount of power transferred may be controlled by adjusting the duty cycle.