Sneak-In Suppression Circuit for Electronic Control Device

Solution Overview

Problem

In electric power steering systems, ground potential differences between systems can lead to sneak currents, causing cascading failures when a ground abnormality occurs, and existing solutions like insulation-type interfaces are costly and space-constrained.

Innovation Solution

The implementation of sneak-in suppression circuits using series resistors or field effect transistors in signal lines connecting control circuit units to separate grounds, which limit sneak currents and prevent failures by setting appropriate resistance values and configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulation-type interfaces are used to prevent sneak currents, then system reliability is improved, but device complexity and cost increase

Engineering Contradiction:

Improvesystem reliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A diode is introduced as an intermediary component in the signal line between control circuit units. The diode allows normal signal communication while blocking sneak currents from flowing between systems with different ground potentials, thus preventing ground abnormalities without requiring complex insulation-type interfaces

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrical characteristics of the signal line are modified by adding a diode with specific forward voltage and reverse breakdown characteristics. This parameter change enables the signal line to differentiate between normal signal levels and abnormal sneak currents, allowing simple and cost-effective suppression of ground-related failures

Inventive Principle:

Principle #35Parameter changes

2Reliability

If insulation-type interfaces are used to prevent sneak currents, then system reliability is improved, but installation space increases

Engineering Contradiction:

Improvesystem reliabilityVSAvoidinstallation space

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

A diode is introduced as an intermediary component in the signal line between control circuit units. The diode allows normal signal communication while blocking sneak currents from flowing between systems with different ground potentials, thus preventing ground abnormalities without requiring complex insulation-type interfaces

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses a simple, inexpensive diode component instead of complex insulation-type interfaces. The diode is a compact, cost-effective solution that provides reliable sneak current suppression without occupying significant installation space

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Object-generated harmful factors

If ground potentials are separated for each system, then sneak currents are reduced, but communication reliability deteriorates due to ground potential differences

Engineering Contradiction:

Improvesneak currentVSAvoidcommunication reliability

Core Design Contradiction:

Object-generated harmful factorsVSReliability

Solution Approach 1:

A diode is introduced as an intermediary component in the signal line between control circuit units. The diode allows normal signal communication while blocking sneak currents from flowing between systems with different ground potentials, thus preventing ground abnormalities without requiring complex insulation-type interfaces

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes the diode's unidirectional conduction property to convert the potential harm of ground potential differences into a beneficial feature. The diode naturally blocks reverse-current sneak paths while maintaining forward signal transmission, turning the ground separation issue into a reliable communication solution

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 suppresses sneak currents during ground abnormalities, ensuring system reliability and safety while maintaining communication speed and reducing the risk of cascading failures, with a simple and cost-effective configuration.

Implementation Method 1

sneak-in suppression circuits which suppress sneak-in of electric power from a ground of another system via a signal line

Methodology Applied

Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

sneak-in suppression circuits using series resistors or field effect transistors in signal lines connecting control circuit units to separate grounds

Methodology Applied

Scientific EffectElectric Field: Electric Field

Data Source

PatentUS11626780B2Electronic control device

Publication Date: 2023.04.11 DENSO CORP

AI summary

An electronic control device includes a plurality of control circuit units, a signal line, and a sneak-in suppression circuit. The plurality of control circuit units are connected to separate grounds, respectively. The signal line connects a first control circuit unit and a second control circuit unit. When a system is defined as a combination of a component and a ground corresponding to a control circuit unit, the sneak-in suppression circuit suppresses a sneak-in of electric power from the ground of one system (i.e., a subject system) to the other system connected by the signal line for preventing a cascading failure.