Vehicle Circuit Protection Arrangement with Voltage Buffer

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Solution Overview

Problem

Existing circuit protection methods in vehicles, such as using protection diodes and transistors, face inefficiencies in power dissipation, voltage drop, and inadequate protection against microcuts and negative pulses, leading to potential damage and inaccurate battery voltage measurement.

Innovation Solution

A circuit protection arrangement utilizing a p-type MOSFET transistor with a control module and voltage buffer, along with a detection module, to quickly respond to power supply disruptions by disconnecting the output from the input, minimizing damage and maintaining accurate voltage measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protection diode is used to protect the electronic circuit from reverse polarity and microcuts, then the electronic circuit is protected from power supply disruptions, but the protection diode dissipates unnecessary power and causes forward voltage drop

Engineering Contradiction:
Improveprotection from power supply disruptionsVSAvoidpower dissipation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the electrical parameters of the protection device by using a transistor instead of a diode, achieving lower forward voltage drop (50mV-100mV vs 0.7V) and reduced power dissipation while maintaining protection functionality against reverse polarity and microcuts

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism using a detection module that monitors the power supply voltage and controls the transistor switching state. The control module receives feedback about power supply conditions and adjusts the transistor accordingly, enabling intelligent protection that reduces unnecessary power dissipation while maintaining reliability

Inventive Principle:
Principle #23Feedback

2Reliability

If a protection diode is used, then the electronic circuit is protected from reverse polarity, but the forward voltage drop of approximately 0.7V reduces the power supply voltage to the electronic circuit

Engineering Contradiction:
Improveprotection from reverse polarityVSAvoidpower supply voltage
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent changes the voltage parameter by using a transistor with significantly lower forward voltage drop (50mV-100mV) compared to a protection diode (0.7V), thereby preserving more power supply voltage for the electronic circuit while maintaining reverse polarity protection capability

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If a transistor is used instead of a protection diode, then power dissipation is reduced and voltage drop is minimized, but the transistor does not provide efficient protection from microcuts and negative pulses

Engineering Contradiction:
Improvepower dissipationVSAvoidprotection from microcuts and negative pulses
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent implements a feedback control system where the detection module monitors power supply conditions including microcuts and negative pulses, and the control module rapidly switches the transistor off when disruptions are detected. This feedback mechanism enables the transistor to provide efficient protection from microcuts and negative pulses while maintaining low power dissipation during normal operation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent makes the transistor switching state dynamic rather than static, using control logic to switch the transistor on or off based on real-time power supply conditions. This dynamic control enables efficient protection from microcuts and negative pulses while minimizing unnecessary power dissipation

Inventive Principle:
Principle #15Dynamics

4Reliability

If a protection diode is used, then the electronic circuit is protected from power supply disruptions, but the voltage drop variations make it difficult to measure the true output voltage of the battery accurately

Engineering Contradiction:
Improveprotection from power supply disruptionsVSAvoidbattery voltage measurement
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the voltage parameter by using a transistor with lower and more stable forward voltage drop (50mV-100mV) compared to a protection diode (0.7V with high temperature dependence). This improvement in voltage parameter stability enables more accurate battery voltage measurement by the electronic circuit

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 solution effectively protects electronic circuits from power supply disruptions, including reverse polarity, microcuts, and negative pulses, while reducing power dissipation and maintaining accurate voltage measurement, thus enhancing the reliability and longevity of vehicle electronic components.

Implementation Method 1

A circuit protection arrangement utilizes a p-type MOSFET transistor with a control module and voltage buffer, along with a detection module, to quickly respond to power supply disruptions by disconnecting the output from the input

Methodology Applied
Scientific EffectMOSFET transistor switching:

Data Source

PatentEP3306767B1A circuit protection arrangement
Publication Date: 2023.01.25 VEONEER SWEDEN SAFETY SYST AB
  • EP3306767B1 patent drawingFigure 1
  • EP3306767B1 patent drawingFigure 2
  • EP3306767B1 patent drawingFigure 3

AI summary

A circuit protection arrangement (11) for use in a vehicle, the arrangement (11) comprising: an input terminal (12) configured to be connected to a power supply (14) to receive a power supply voltage; an output terminal (15) configured to be connected to an electronic circuit (16) to provide an output voltage to the electronic circuit (16); a controllable switch (19) which is connected in series between the input and output terminals (12, 15); a control module (20) which is coupled to controllable switch (19); a voltage buffer module (21) coupled to the input terminal (12), the voltage buffer module (21) being configured to store electrical energy and to provide a buffer output voltage for a predetermined length of time, the buffer output voltage being substantially equal to the power supply voltage; and a detection module (27) coupled to the input terminal (12), the voltage buffer module (21) and the control module (20), the detection module (27) being configured to detect if the power supply voltage is substantially equal to the buffer output voltage and to provide: a first control signal to the control module (20) if the power supply voltage is substantially equal to the buffer output voltage, and a second control signal to the control module (20) if the power supply voltage is lower than the buffer output voltage, wherein the control module (20) is configured to control the controllable switch (19) to: switch on in response to the first control signal so that the protection arrangement (11) provides a voltage at the output terminal (15) which is substantially equal to the power supply voltage, and switch off in response to the second control signal so that the protection arrangement (11) does not provide a voltage at the output terminal (15) to protect an electronic circuit (16) connected to the output terminal (15).