Charging Cradle Switch Mechanism Prevents Short-Circuit

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Solution Overview

Problem

Current charging cradles often short-circuit due to conductive device housings coming into contact with charging contacts, leading to improper charging and potential damage.

Innovation Solution

Incorporation of a switch mechanism, such as a pivotally mounted actuator or electro-mechanical switch, that positions the charging contact in a non-charging state unless the rechargeable medium is fully inserted, preventing short-circuiting by decoupling the charging contact when not in use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the charging contact is always in contact with the housing, then the device can be charged at any time, but the charging circuit may be short-circuited

Engineering Contradiction:
Improvecharging availabilityVSAvoidshort-circuit prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The charging contact is made movable rather than fixed, allowing it to dynamically adjust its position between extended (charging mode) and retracted (safe mode) states based on whether a device is properly inserted, thus preventing short-circuits while maintaining charging availability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The charging contact is extended in advance before device insertion, and the system proactively retracts it when device removal is detected, preventing potential short-circuits before they can occur

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the charging contact is retracted to prevent short-circuiting, then safety is improved, but charging cannot begin until proper insertion is detected

Engineering Contradiction:
Improveshort-circuit preventionVSAvoidcharging delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The charging contact is extended in advance before the device is inserted into the cradle. When the device is properly inserted, the charging contact is already in position to make immediate electrical connection, eliminating any charging delay while still maintaining safety by retracting when the device is removed

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a switch mechanism is added to control charging contact position, then short-circuit prevention is improved, but device complexity increases

Engineering Contradiction:
Improveshort-circuit preventionVSAvoidswitch mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The charging contact's movement is automatically controlled by the presence or absence of the device itself. The device's insertion and removal actions directly trigger the charging contact to extend or retract, eliminating the need for separate switches or complex control mechanisms while still achieving reliable short-circuit prevention

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2458706B1Charging cradle
Publication Date: 2013.03.27 BLACKBERRY LTD
  • EP2458706B1 patent drawingFigure 1A~1B
  • EP2458706B1 patent drawingFigure 2
  • EP2458706B1 patent drawingFigure 3A

AI summary

A charging cradle for a rechargeable medium having a charging contact. The charging cradle including a cradling-body, which includes a receiving area shaped to receive the rechargeable medium; a charging circuit having a charging and a non-charging state; a charging contact electrically coupled to the charging circuit and positioned to be alignable with the charging contact of the rechargeable medium; and a switch coupled to the cradling-body for interacting with the rechargeable medium to place the charging circuit in the charging state or the non-charging state. When the rechargeable medium is fully inserted into the receiving area such that the charging contact of the rechargeable medium is aligned with the charging contact of the cradling-body, the rechargeable medium, via the switch, places the charging circuit in the charging state, and when the rechargeable medium is not fully inserted, the switch places the charging circuit in the non-charging state to prevent short-circuiting of the charging circuit.