USB Contact Foreign Object Detection Without Moisture Sensor
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Solution Overview
Problem
USB 3.1 type electronic devices face corrosion issues due to foreign objects like moisture at identification contacts, and existing solutions require a moisture sensor, which is not always necessary or effective.
Innovation Solution
An electronic device with a second circuit that detects foreign objects by sensing abnormal voltage levels or impedance at a first contact, eliminating the need for a moisture sensor and preventing corrosion by controlling current flow through switching circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a moisture sensor is used to detect foreign objects at USB contacts, then detection capability is improved, but device complexity and cost increase
Solution Approach 1:
The USB contact itself performs the detection function by sensing abnormal voltage or impedance when a foreign object is present, eliminating the need for a separate moisture sensor. The contact serves both its original electrical function and the additional foreign object detection function simultaneously.
Solution Approach 2:
The existing USB contact structure is made multi-functional by enabling it to detect foreign objects through voltage or impedance sensing in addition to its primary electrical connection function, thereby eliminating the need for dedicated detection hardware.
2Reliability
If current is continuously applied to identification contacts to define device roles, then role determination is improved, but corrosion risk increases
Solution Approach 1:
Instead of continuously applying current to identification contacts, the system periodically applies current only when needed for role determination, reducing the overall exposure time to corrosive environments while maintaining reliable role definition capability.
Solution Approach 2:
The system performs foreign object detection before applying current to identification contacts. If a foreign object is detected, the current application is prevented or interrupted, thereby preventing corrosion while still allowing role determination to proceed when conditions are safe.
3Object-affected harmful factors
If a switching device is added to control current flow based on foreign object detection, then corrosion prevention is improved, but device complexity increases
Solution Approach 1:
The switching function is integrated into the existing USB controller or power management circuitry, merging the corrosion prevention control with existing device functions rather than adding a completely separate switching mechanism.
Solution Approach 2:
The system uses feedback from the voltage/impedance sensing at the USB contact to automatically control the switching device, which in turn controls current application. This closed-loop feedback mechanism enables automatic corrosion prevention without requiring complex external control systems.
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 detects and prevents corrosion at USB contacts without a moisture sensor, ensuring reliable operation and reducing power consumption by controlling current flow based on foreign object presence.
Implementation Method 1
a second circuit configured to sense existence of a foreign object contacting the first contact by detecting an abnormal voltage level or impedance
Data Source
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AI summary
An electronic device includes a housing, a display device exposed through a first part of the housing, a recess formed in a second part of the housing, a receptacle formed in the recess, a plurality of conductive contacts disposed inside the receptacle and including a first contact, a first circuit that supplies and/or receives a current of a first level or larger to and/or from the first contact when an external connector is inserted into the receptacle, a first switching device that electrically connects the first circuit with the first contact or to interrupt a connection between the first circuit and the first contact, a second circuit that detects existence of a foreign object contacting the first contact while the external connector is inserted into the receptacle and a control circuit that controls the first switching device based at least in part on information regarding the detected existence of the foreign object.