Current Mirror Charging Circuit for Stable Battery Current Control

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Solution Overview

Problem

Conventional charging devices provide unstable current and voltage, affecting battery charging efficiency and service life.

Innovation Solution

A constant current charging device comprising a reference current source, current mirror, current adjusting unit, and current compensation unit, which allows for stable and controllable charging current and voltage through adjustable transistor ratios and operational amplifier configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional constant current charging mode is used, then charging can be performed, but the current and voltage are unstable affecting charging efficiency and battery service life

Engineering Contradiction:
Improvestability of charging current and voltageVSAvoidcharging efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent employs feedback mechanisms through operational amplifiers that continuously monitor the charging current and voltage. The first operational amplifier compares the voltage across the charging current with a reference voltage, and the second operational amplifier compares the voltage across the charging voltage with a reference voltage, automatically adjusting the output to maintain stability and resolve the contradiction between reliability and productivity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the parameters of the charging circuit by introducing adjustable resistors and capacitors that allow precise control of the charging current and voltage levels. By adjusting these components, the system can optimize the charging parameters to maintain stability while maximizing charging efficiency, thus resolving the technical contradiction.

Inventive Principle:
Principle #35Parameter changes

2Duration of action of stationary object

If conventional charging device is used, then charging function is provided, but the unstable current or voltage decreases battery service life

Engineering Contradiction:
Improvebattery service lifeVSAvoidstability of output current and voltage
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The dual operational amplifier configuration provides continuous feedback control that monitors and stabilizes both charging current and voltage. This feedback mechanism ensures that the battery receives stable, controlled charging parameters throughout the charging process, preventing damage from voltage spikes or current fluctuations and thereby extending battery service life.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent incorporates protection circuits that anticipate potential overcharging or voltage instability issues before they occur. The circuit design includes safety mechanisms that preemptively regulate the charging parameters to prevent conditions that would otherwise harm the battery, thus cushioning against future damage and extending service life.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS11848583B2Constant current charging device
Publication Date: 2023.12.19 SILICON INTEGRATED SYSTEMS CORP
  • US11848583B2 patent drawing
  • US11848583B2 patent drawing

AI summary

A constant current charging device is configured to charge a device to be charged and includes: a reference current source configured to provide a reference current; a current mirror electrically coupled to the reference current source and configured to output a mirror current; a current adjusting unit electrically coupled to the current mirror and the device to be charged and configured to output a charging current according to the mirror current to charge the device to be charged; and a current compensation unit electrically coupled to the current mirror and the current adjusting unit and configured to adjust the charging current according to a reference voltage.