Wireless Power Receiver Modulating Battery Charge Current

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Solution Overview

Problem

Existing wireless power receivers have inefficiencies in power transfer due to the power-consuming nature of back scattering techniques that modulate loads referred to ground, which limits their power efficiency.

Innovation Solution

A power receiver architecture that modulates the charge current of a battery instead of using a resistive load, incorporating a resonant circuit with secondary and auxiliary capacitances, a voltage regulator, and a voltage-to-current converter to transmit information about the load's functioning state through the charge current, reducing power losses by avoiding current dissipation through a resistor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If back scattering technique is used to transmit information by modulating a load referred to ground, then data transmission is achieved, but power efficiency deteriorates due to current dissipation through resistor

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidpower efficiency

Core Design Contradiction:

Loss of informationVSLoss of energy

Solution Approach 1:

The patent extracts the resistive load from the ground reference and relocates it to the positive supply terminal. This extraction eliminates the harmful current dissipation path through ground while maintaining the back scattering data transmission capability through the battery charge current modulation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The battery charge current serves as an intermediary carrier for data transmission. Instead of using a separate resistive load that dissipates power, the modulation of the battery charge current itself carries the information, eliminating the need for a power-dissipating resistive path.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of information

If a resistive load is used for back scattering modulation, then information can be transmitted, but power losses increase due to current shunting through resistor

Engineering Contradiction:

Improveinformation transmissionVSAvoidpower losses

Core Design Contradiction:

Loss of informationVSLoss of energy

Solution Approach 1:

Instead of shunting current through a resistive load to ground for modulation, the patent inverts the approach by modulating the main battery charge current flowing through the secondary coil. This inversion eliminates the parallel current path through resistor while maintaining modulation capability.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The battery charge current serves multiple functions simultaneously: it charges the battery and carries the modulated information signal. This multi-functionality eliminates the need for a separate resistive load dedicated solely to data transmission, thereby reducing power losses.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Power

If conventional power receiver architecture is used, then power transfer occurs, but power transfer efficiency is insufficient for modern appliances with strict power consumption requirements

Engineering Contradiction:

Improvepower transfer capabilityVSAvoidpower transfer efficiency

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent changes the reference parameter of the load from ground to positive supply terminal. This parameter change fundamentally alters the current flow path, eliminating the ground-referenced resistive loss path while maintaining the necessary power transfer capability for modern appliances.

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 enhances power transfer efficiency by minimizing power losses during data transmission, as the current flowing through the secondary coil is modulated by varying the battery charge current, rather than shunting current through a resistive load, thereby reducing energy dissipation and improving overall system performance.

Implementation Method 1

use coupled electromagnetic (EM) fields from a primary subsystem (power transmitter) to transfer power through a nonconductive medium. The field is captured in a secondary subsystem and converted to useable energy.

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Improved system efficiencies due to the emergence of resonant transfer of power

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS9973039B2Power receiver, wireless power system and related method of transmitting information with a power receiver

Publication Date: 2018.05.15 STMICROELECTRONICS INT NV

AI summary

A power receiver includes a resonant circuit generating an internal supply voltage. A voltage rectification circuit receives the internal supply voltage and generate a corresponding rectified voltage. A voltage regulator receives the rectified voltage and a modulation signal and is configured to generate a corresponding regulated voltage. A controlled voltage-to-current converter receives the regulated voltage and the modulation signal. The converter operates to deliver, through an output line of the power receiver, an output current having a DC value corresponding to the DC value of said regulated voltage and having an AC value corresponding to said modulation signal.