Parallel Battery Receptacle Circuit With MOSFET Polarity Bypass

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing power supply systems with batteries connected in parallel face issues such as voltage drops and reduced battery life due to blocking diodes, and lack effective monitoring and control for proper polarity and differential voltage management, leading to potential damage or explosion from improper installation or malfunction.

Innovation Solution

A power supply receptacle circuit with multiple transistors and bypass channels that provide reverse polarity protection and current blocking, along with a bypass control circuit to manage the flow based on polarity orientation and differential voltage, ensuring safe and efficient power delivery by selectively using body diodes or bypass channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If blocking diodes are used to prevent reverse current flow in parallel battery connections, then reverse polarity protection is improved, but voltage drops occur that reduce supply voltage and battery service life

Engineering Contradiction:
Improvereverse polarity protectionVSAvoidbattery service life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent changes the electrical parameters of the protection mechanism by using MOSFETs with dynamically adjustable resistance. Instead of fixed diode voltage drops, the MOSFETs operate in different regions (linear or saturation) to provide protection with minimal voltage drop, thereby extending battery service life while maintaining reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The protection circuit transitions from static diode-based protection to dynamic MOSFET-based protection. The MOSFETs can switch between conductive and non-conductive states based on battery polarity detection, and their channel resistance can be dynamically adjusted through gate voltage control to optimize both protection and voltage drop minimization

Inventive Principle:
Principle #15Dynamics

2Reliability

If blocking diodes are used to prevent reverse current flow, then reverse polarity protection is improved, but the resultant supply voltage is reduced

Engineering Contradiction:
Improvereverse polarity protectionVSAvoidsupply voltage
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent changes the electrical characteristics of the protection element from high forward voltage drop diodes to low resistance MOSFETs. By controlling the MOSFET channel resistance through gate voltage, the circuit achieves reverse polarity protection with minimal impact on supply voltage, thereby maintaining power output

Inventive Principle:
Principle #35Parameter changes

3Reliability

If conventional reverse battery protection circuits with MOSFETs are used, then reverse polarity protection is improved, but device complexity increases due to additional control requirements

Engineering Contradiction:
Improvereverse polarity protectionVSAvoidcontrol circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protection circuit performs self-diagnosis and self-protection through automatic polarity detection. The MOSFETs are configured with their body diodes oriented to naturally block reverse current, and the gate control logic automatically responds to polarity conditions without requiring external control signals, thereby reducing overall system complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent combines multiple functions into the MOSFET structure itself: the body diode provides inherent reverse blocking, the channel provides low-resistance forward conduction when properly biased, and the gate control integrates polarity detection and protection activation. This merging reduces the need for separate protection components and control circuits

Inventive Principle:
Principle #5Merging (Combining)

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

The solution effectively prevents voltage drops and extends battery life by ensuring proper polarity and voltage management, reducing the risk of damage or explosion from improper installation, while maintaining efficient power delivery.

Implementation Method 1

a first transistor to provide reverse polarity protection for output from the positive terminal of the first power source by a first body diode of the first transistor

Methodology Applied
Scientific EffectDiode rectification: Diode

Implementation Method 2

an indication that a differential voltage between the terminal voltages of the first and second power sources is above a predetermined threshold

Methodology Applied
Scientific EffectVoltage measurement: Ohm's Law

Data Source

PatentEP3113322B1Receptacle circuit for monitoring and controlling parallel batteries
Publication Date: 2023.11.22 CARRIER CORP
  • EP3113322B1 patent drawingFigure 1
  • EP3113322B1 patent drawingFigure 2
  • EP3113322B1 patent drawingFigure 3

AI summary

A receptacle circuit 100 is provided that includes a first circuit path that provides reverse current blocking and reverse polarity protection associated with a positive terminal 124 of a first power source 108 that is connected in parallel with a second power source 110, a second circuit path that bypasses blocking of the first circuit path, a third circuit path that provides reverse polarity protection associated with a negative terminal 126 of the first power source, and a bypass control circuit 106 that controls the first and second circuit paths based on determination of a predetermined condition.