Vehicle Control Unit Overvoltage Circuit With Lifetime Testability

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Solution Overview

Problem

Existing overvoltage protection circuits for control devices in vehicles cannot be effectively tested for correct function during their lifespan, and they often require special components, which increases costs and complexity.

Innovation Solution

A cost-effective overvoltage protection circuit designed using discrete components, allowing for cyclic testing with two different input levels, and integrated into the control device, enabling continuous testing throughout its service life without requiring special components, with a simple adjustment mechanism for limiter voltage using standard components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing overvoltage protection circuits are used, then overvoltage protection function is provided, but they cannot be tested for correct function during the control unit's lifetime

Engineering Contradiction:
Improveovervoltage protection functionVSAvoidtestability
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent incorporates a test voltage divider circuit and test control logic that enables preliminary testing of the overvoltage protection circuit during normal operation. The test mode allows cyclic activation with two different input levels to verify correct function throughout the control unit's service life, rather than waiting for failure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a test voltage divider circuit as an intermediary component that allows external test signals to be applied to the overvoltage protection circuit without disrupting normal operation. This intermediary structure enables measurement and verification of the protection circuit's functionality during normal use.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If special components are used to implement overvoltage protection circuit, then protection function is achieved, but costs and complexity increase

Engineering Contradiction:
Improveovervoltage protection functionVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the overvoltage protection circuit using standard voltage divider components that also serve normal voltage monitoring functions. The same voltage divider network is used both for overvoltage detection and for general voltage reference purposes, eliminating the need for special dedicated components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The test voltage divider circuit uses the existing voltage reference and division infrastructure to generate test signals and measurement points. The circuit serves itself by utilizing its own components for both protection and testing functions, rather than requiring separate specialized components.

Inventive Principle:
Principle #25Self-service

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 provides reliable overvoltage protection, allows for safe and efficient power supply switching, and enables resource-saving hardware configurations by enabling continuous testing and adjustment of the overvoltage protection circuit, ensuring reliable operation and safety throughout the vehicle's control systems.

Implementation Method 1

a reference device configured to provide a reference voltage using the input voltage

Methodology Applied
Scientific EffectVoltage division: Electrical Resistance

Implementation Method 2

a division device configured to provide a partial voltage using the output voltage

Methodology Applied
Scientific EffectVoltage division: Electrical Resistance

Implementation Method 3

a regulating device connected between the input terminal and the output terminal, wherein the regulating device is configured to provide the output voltage using the input voltage and the regulating signal

Methodology Applied
Scientific EffectVoltage regulation: Electrical Resistance

Data Source

PatentEP3874282B1Overvoltage protection circuit for a control unit for a vehicle, control unit for a vehicle and method for testing an overvoltage protection circuit for a control unit for a vehicle
Publication Date: 2024.06.05 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH
  • EP3874282B1 patent drawingFigure 1
  • EP3874282B1 patent drawingFigure 2~3
  • EP3874282B1 patent drawingFigure 4

AI summary

The invention relates to an overvoltage protection circuit (120) for a control unit for a vehicle. The overvoltage protection circuit (120) comprises an input terminal (122) for applying an electrical input voltage (Uin), a test terminal (126) for applying an electrical test voltage (TST) and an output terminal (124) for providing an electrical output voltage (Uout) for supplying the control unit. The overvoltage protection circuit (120) also comprises a reference device (221) which is designed to provide a reference voltage (Uref) using the input voltage (Uin). The overvoltage protection circuit (120) further comprises a dividing device (223) which is designed to provide a voltage component using the output voltage (Uout). The overvoltage protection circuit (120) additionally further comprises a control device (225) which is designed to provide a regulating signal using the reference voltage (Uref) and the voltage component. The overvoltage protection circuit (120) also comprises a regulating device (227) which is connected between the input terminal (122) and the output terminal (124). The regulating device (227) is designed to provide the output voltage (Uout) using the input voltage (Uin) and the regulating signal. The overvoltage protection circuit (120) further comprises a modification device (229) which is designed to modify a value of the voltage component using the test voltage (TST).