Pyro-Switch Shunt Resistor Protection Diode

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Solution Overview

Problem

When a shunt resistor is cut by a pyro-switch in high-voltage applications, such as electric vehicles, the stored energy in the wiring and battery components can cause high voltage, leading to destruction and burnout of the battery and peripheral devices.

Innovation Solution

A protection system is introduced that includes a shunt resistor, a pyro-switch for cutting the resistor based on a predetermined signal, and a suppression unit, specifically a diode, connected between the resistor and the load unit, which suppresses the energy generated by the cutting action.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the shunt resistor is cut by the pyro-switch to disconnect the battery wiring, then the safety against short circuit and overcurrent is improved, but the stored energy in the wiring and battery components generates high voltage causing sparks and destruction

Engineering Contradiction:
Improvesafety against short circuit and overcurrentVSAvoidhigh voltage and sparks causing destruction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A diode is introduced as an intermediary component between the shunt resistor and the load unit. The diode provides a controlled path for the stored energy to dissipate safely after the shunt resistor is cut, preventing harmful high voltage and sparks while maintaining the safety function of the pyro-switch

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the base material of the shunt resistor is cut by the pyro-switch, then the circuit disconnection function is achieved, but the inductance energy of the wiring and battery components causes high voltage leading to burnout

Engineering Contradiction:
Improvecircuit disconnection functionVSAvoidresistance to high voltage and burnout
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The diode is pre-installed in the circuit to provide a protective path for energy dissipation. When the shunt resistor is cut, the stored energy is immediately directed through the diode, cushioning the impact and preventing high voltage damage to the battery and peripheral devices

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 suppression unit effectively reduces the high voltage on the load unit, preventing damage to the battery and peripheral devices by allowing the energy to be safely dissipated, thus protecting the system from destruction and burnout.

Implementation Method 1

the suppression unit (2) is composed of a diode (20), and the diode (20) has a cathode side (20a) connected between the shunt resistor (100) and the load unit (for example, the motor M), and the diode (20) has an anode side (20b) connected to the load unit (for example, the motor M)

Methodology Applied
Scientific EffectDiode rectification: Diode

Implementation Method 2

a cutting unit 203 for cutting the base material 102 of the shunt resistor 100 by the exploded powder 202

Methodology Applied
Scientific EffectThermal melting/vaporization: Melting

Data Source

PatentEP3820009B1Protection system
Publication Date: 2023.07.05 SUNCALL CORP
  • EP3820009B1 patent drawingFigure 1
  • EP3820009B1 patent drawingFigure 2~2(b)
  • EP3820009B1 patent drawingFigure 3

AI summary

The purpose of the present invention is to provide a protection system capable of suppressing, using a pyro-switch, energy generated when cutting battery wiring. The protection system has: a shunt resistor 100 for measuring the value of current flowing from a battery B to a motor M; a pyro-switch 200 for cutting a shunt resistor 100 on the basis of a predetermined signal; and a suppression unit 2 connected between the shunt resistor 100 and the motor M. The suppression unit 2 suppresses the energy generated by cutting the shunt resistor 100 by the pyro-switch 200.