Wireless Charging Overvoltage Circuit With Dual Protection Timing

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Solution Overview

Problem

In wireless charging systems, overvoltage can occur when an electronic device is not accurately aligned with the charging pad, potentially damaging the battery and the wireless charging circuit.

Innovation Solution

The implementation of a dual overvoltage protection circuit system, comprising a first circuit with a current source and a second circuit with a resistor, which are alternately turned on and off to efficiently generate power loss when overvoltage occurs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a single overvoltage protection circuit is used, then the circuit structure is simple, but the power loss efficiency is insufficient when overvoltage occurs

Engineering Contradiction:

Improvepower loss efficiencyVSAvoidcircuit structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The overvoltage protection circuit is divided into two separate protection circuits: a first overvoltage protection circuit and a second overvoltage protection circuit. Each circuit operates independently and can be selectively activated based on detection results, allowing for more efficient power loss management while maintaining manageable circuit complexity through modular design.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The controller dynamically switches between the first and second overvoltage protection circuits based on real-time detection of overvoltage conditions. The controller activates the appropriate circuit depending on the severity and nature of the overvoltage event, enabling adaptive power loss efficiency without requiring a permanently complex circuit structure.

Inventive Principle:

Principle #15Dynamics

2Reliability

If overvoltage protection is activated continuously, then the battery and circuit are protected, but excessive power loss occurs and temperature increases

Engineering Contradiction:

Improveprotection reliabilityVSAvoidpower loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The controller periodically detects overvoltage conditions and selectively activates the first or second protection circuit based on the detection results. This periodic detection and selective activation approach ensures reliable protection only when needed, avoiding continuous power loss and excessive temperature increase while maintaining battery and circuit safety.

Inventive Principle:

Principle #19Periodic action

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 effectively prevents damage to the battery and the wireless charging circuit by maintaining efficient power loss and controlling temperature within a predetermined range, thereby ensuring reliable operation.

Implementation Method 1

a first overvoltage protection circuit that includes a current source and a second overvoltage protection circuit that includes a resistor and by alternately turning the first and second overvoltage protection circuits on and off to efficiently generate power loss when overvoltage occurs

Methodology Applied

Scientific EffectPower loss generation: Joule Heating

Implementation Method 2

Methodology Applied

Scientific EffectPower loss generation: Joule Heating

Implementation Method 3

a power receiving circuit that wirelessly receives power and includes an inductor and a capacitor

Methodology Applied

Scientific EffectWireless power transfer: Electromagnetic Induction

Data Source

PatentUS20250038574A1Wireless charging circuit

Publication Date: 2025.01.30 SAMSUNG ELECTRONICS CO LTD

AI summary

A wireless charging circuit wirelessly receives power and includes a power receiving circuit that includes an inductor and a capacitor, a rectifier circuit that rectifies an alternating current voltage received from the power receiving circuit and outputs a rectified voltage, a regulating circuit that outputs a charging voltage that charges a battery using the rectified voltage, an overvoltage protection circuit connected in parallel between the rectifier circuit and the regulating circuit, and a controller that detects the rectified voltage and controls the overvoltage protection circuit. The overvoltage protection circuit includes first and second overvoltage protection circuits. By separating turn-on holding times of the first and second overvoltage protection circuits, the wireless charging circuit is effectively protected from overvoltage and damage to the circuit due to heat generation is prevented.