Vehicle Power Distributor PCB Thermal Overload Protection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing electronic power distributor arrangements in vehicles face high design complexity and manufacturing costs due to the replacement of fuses with MOSFET switches, and current-based thermal overload protection is inaccurate, leading to unnecessary shutdowns and wide tolerance bands.

Innovation Solution

A modular electronic power distributor arrangement where load channels are subdivided into conductor paths on a circuit board and separate supply lines, using transistor switches with temperature-based evaluation units to detect thermal overload directly, reducing the need for individual current measurements and allowing cost-effective, channel-specific protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If MOSFET switches are used in each load channel to provide channel-selective electronic protection, then rapid disconnection and fault protection are improved, but design complexity and manufacturing costs increase significantly

Engineering Contradiction:

Improvefault protectionVSAvoiddesign complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple load channels (specifically four channels) into a single protection group controlled by one MOSFET switch. This merging approach reduces the total number of MOSFET switches from potentially 300 (one per channel) to just 75 (one per group of four channels), thereby reducing design complexity and manufacturing costs while maintaining channel-selective protection capability through the grouping strategy

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If current measurement-based thermal overload protection is used, then thermal protection is provided, but measurement precision deteriorates due to tolerances and environmental temperature variations

Engineering Contradiction:

Improvethermal protectionVSAvoidtemperature measurement accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the indirect electrical measurement method (current measurement) with a direct thermal measurement method (temperature sensors). Temperature sensors are placed in direct thermal contact with the MOSFET switches and conductor paths, providing accurate temperature feedback without being subject to current measurement tolerances or environmental temperature variations that affect current-based I²t calculations

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If individual MOSFET switches are used for each of up to 300 fuses, then channel-selective protection is achieved, but manufacturing costs increase

Engineering Contradiction:

Improvechannel-selective protectionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent implements a grouping strategy where multiple load channels are assigned to single MOSFET switches. Specifically, four load channels are combined into one protection group, reducing the required number of MOSFET switches from 300 to 75. This merging maintains channel-selective protection capability while significantly reducing component count and manufacturing costs

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

This approach achieves a significant cost reduction and increased current-carrying capacity by directly measuring conductor temperatures, minimizing unnecessary shutdowns and enhancing safety by differentiating between load channels within permitted ranges.

Implementation Method 1

Temperature sensors are placed on the circuit board in a matrix arrangement and serve to determine the conductor path temperatures

Methodology Applied

Scientific EffectTemperature sensing:

Implementation Method 2

The temperatures of the supply lines are calculated from the conductor path temperatures taking into account the thermal coupling between the supply lines and the conductor paths

Methodology Applied

Scientific EffectThermal coupling: Conduction (thermal)

Implementation Method 3

The switch unit is configured to disconnect a load channel in the event that a supply line is thermally overloaded

Methodology Applied

Scientific EffectThermal overload protection:

Data Source

PatentUS20250309635A1Electronic power distributor arrangement and method for operating such a power distributor arrangement

Publication Date: 2025.10.02 LISA DRAXLMAIER GMBH

AI summary

An electronic power distributor arrangement for a vehicle on-board network having at least one load path emanating from an on-board battery, which splits into at least one or more load channels to each of which electrical consumers are connected. Each of the load channels is subdivided into a conductor path applied onto a circuit board, and a supply line leading to the consumer. The load path includes a switch unit that switches off the load path in the event of a thermal overload of one of the supply lines. An evaluation device is assigned with the switch unit, and the evaluation device is to determine a thermal overload of one of the supply lines based on the conductor path temperatures of the conductor paths.