Battery Pack Malfunction Detection via Temperature Interface Inversion

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Solution Overview

Problem

Existing battery packs for electric hand tools lack a reliable method for detecting malfunctions, particularly in temperature measurement, which can lead to unsafe operation or charging conditions.

Innovation Solution

Influencing the temperature measurement interface to alter resistance or voltage, allowing for the detection of malfunctions by generating a change in resistance or temperature values that can be evaluated externally, enabling safe and reliable error detection and mitigation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an analog temperature sensor is used for temperature measurement, then temperature monitoring is enabled, but reliable malfunction detection is not achieved

Engineering Contradiction:
Improvemalfunction detection reliabilityVSAvoidtemperature measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

Instead of measuring temperature directly to detect malfunctions, the patent inverts the approach by intentionally introducing a known resistance change (via switch opening) to create a detectable signal. This inverted method uses the measurement interface to detect the presence/absence of the intentional resistance change, providing reliable malfunction detection without compromising temperature measurement functionality.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces a switch as an intermediary element that can be opened to create a resistance change. This intermediary mechanism allows the system to generate a detectable signal through the temperature measurement interface without directly interfering with the temperature sensor's normal operation, enabling reliable malfunction detection while preserving measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the temperature measurement interface is used for both temperature monitoring and malfunction detection, then device complexity is reduced, but measurement precision may be affected

Engineering Contradiction:
Improvecircuit arrangement complexityVSAvoidtemperature measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent makes the temperature measurement interface multi-functional by using it for both temperature monitoring and malfunction detection. The same interface that measures temperature is also used to detect the resistance change caused by opening the switch, eliminating the need for separate detection circuits and reducing overall device complexity while maintaining measurement precision through temporal separation of functions.

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

Solution Approach 2:

The patent employs periodic action by opening the switch at specific intervals to generate detectable resistance changes. This periodic interruption creates distinct measurement phases where the system can alternately perform temperature monitoring and malfunction detection using the same interface, reducing complexity without compromising the precision of either function.

Inventive Principle:
Principle #19Periodic action

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 approach provides a simple and effective method for detecting battery pack malfunctions, ensuring safe operation by allowing external circuits to react appropriately to error conditions, such as overheating or electrical defects, and enabling precise error identification and mitigation.

Implementation Method 1

a second electrical resistor 12, which is formed in the form of an NTC resistor with a negative temperature coefficient

Methodology Applied
Scientific EffectNegative temperature coefficient: Thermistor

Data Source

PatentEP2319154B1Battery pack
Publication Date: 2016.06.08 ROBERT BOSCH GMBH
  • EP2319154B1 patent drawingFigure 1
  • EP2319154B1 patent drawingFigure 2~3
  • EP2319154B1 patent drawingFigure 4~5

AI summary

A battery pack for a corresponding electric hand tool with an analogue temperature sensor with a negative temperature coefficient, a temperature measurement interface accessible from the exterior and an analytical unit which monitors the battery pack for an error function, wherein the analytical unit is designed such that on an error function of the battery pack a voltage at the temperature interface is actively changed.