Plug-side connector short circuit prevention

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Solution Overview

Problem

Existing USB connectors lack effective prevention of short circuits between power supply terminals and ground electrodes, particularly when overcurrents occur due to wiring errors or device-side connector issues, leading to potential damage before user notification.

Innovation Solution

A plug-side connector design incorporating capacitors with lower impedance to alternating currents and higher impedance to direct currents is used between the power supply terminal, metal plate, and ground electrode, preventing short circuits by maintaining high impedance to direct currents and allowing high-frequency noise passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a PTC fuse is used as an overcurrent preventing section, then overcurrents are redirected to a pathway with LED notification, but the fuse fails to prevent overcurrents from reaching the device-side connector and causing short circuits

Engineering Contradiction:
Improveovercurrent protectionVSAvoidshort circuit damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A ground spring is introduced as an intermediary protective element positioned between the host-side connector and the device-side connector. This ground spring acts as a sacrificial component that makes contact first during insertion, providing a safe ground path before the power supply terminal makes contact, thereby preventing direct short circuits between power and ground electrodes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The ground spring is designed to make contact during the insertion process before the power supply terminal establishes connection. This preliminary grounding action ensures that the connector is already grounded when power is introduced, preventing short circuits that would occur if power contacted ground first or simultaneously.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the ground spring is positioned to contact first during insertion, then short circuits are prevented, but the connector structure becomes more complex

Engineering Contradiction:
Improveshort circuit preventionVSAvoidconnector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ground spring is merged with the existing connector assembly, integrating the protective function into the standard connector structure. The ground spring utilizes the same insertion motion and spatial arrangement as the power terminal, combining multiple functions (grounding, protection, connection establishment) into a unified structural approach rather than adding separate independent mechanisms.

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

Effectively prevents short circuits between power supply terminals and ground electrodes, even in the presence of overcurrents or foreign substances, ensuring safe operation and reducing the risk of device damage.

Implementation Method 1

a first capacitor (16a) connected between the center plate (12) and the ground electrode (11a), and a second capacitor (16b) connected between the outer jacket (15b) and the ground electrode (11a), wherein the first capacitor (16a) and the second capacitor (16b) each have a characteristic in which impedance with respect to direct current is higher than impedance with respect to alternating current

Methodology Applied
Scientific EffectCapacitive impedance: Capacitance

Data Source

PatentEP3399601B1Plug-side connector
Publication Date: 2020.01.01 SHARP KK
  • EP3399601B1 patent drawingFigure 1
  • EP3399601B1 patent drawingFigure 2~3
  • EP3399601B1 patent drawingFigure 4

AI summary

The present invention effectively prevents a short circuit from occurring between a power supply terminal and a ground electrode. In a plug-side connector (1), a first protection element (first capacitor 16a) is provided between a metal plate (center plate 12) and a ground electrode (11a) and a second protection element (second capacitor 16b) is provided between an outer jacket (15b) of a cable (15) and the ground electrode (11a), inside a shell part (23).