Electrical Contact Surface Probing for Human Touch Detection
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Solution Overview
Problem
Existing technologies fail to effectively mitigate the risks of electrical shocks by not adequately detecting living body contact before power supply, which can lead to fatal accidents due to the unpredictable and varying electrical properties of the human body.
Innovation Solution
A method and apparatus for detecting living body contact using a non-hazardous probing signal that evaluates responsive signals to determine if a current inrush pattern indicative of a living body is present, utilizing a serially connected RC network model to characterize the body's electrical response, and a power switching apparatus to prevent power supply in case of contact detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a probing signal is applied to detect living body contact, then detection accuracy is improved, but the complexity of the detection system increases
Solution Approach 1:
The system applies a probing signal before main power supply to detect living body contact in advance. This preliminary detection action prevents fatal electric shocks by identifying the presence of a living body through characteristic current response patterns (inrush current followed by steady state current) before hazardous power is applied.
Solution Approach 2:
A probing signal serves as an intermediary between the detection system and the living body. This low-voltage probing signal safely interacts with the body's electrical properties (resistance and capacitance) to elicit a characteristic response pattern that identifies living body contact without causing harm, while the system analyzes the current response to make detection decisions.
2Productivity
If power supply is continuously provided to ensure operational readiness, then productivity is improved, but the risk of electrical shock increases
Solution Approach 1:
The system performs preliminary living body detection through probing signal application before enabling main power supply. This ensures that power is only supplied when no living body is in contact with the output terminal, eliminating the trade-off by preventing hazardous power application through advance detection rather than continuous monitoring during power supply.
Solution Approach 2:
The system applies a counter-action by blocking power supply when living body contact is detected. The probing signal triggers a safety mechanism that prevents the main power switch from closing, thereby applying an anti-action (preventing power flow) that counteracts the potential harmful effect of electrical shock while maintaining operational readiness through conditional power supply.
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 solution effectively determines living body contact through characteristic electrical responses, preventing hazardous power supply and reducing the risk of electrical shocks by ensuring safe operation conditions.
Implementation Method 1
different parts of the human body can be regarded as forming a circuit comprising distributed resistive (R) and capacitive (C) components
Implementation Method 2
different parts of the human body can be regarded as forming a circuit comprising distributed resistive (R) and capacitive (C) components
Data Source
Figure 1~2A2
Figure 2B1~2C2
Figure 3~3A2
AI summary
A method of detecting possible living body contact at an electrical contact surface, wherein the living body has a detectable characteristic initial impedance and a corresponding characteristic time constant defined by the initial impedance upon touching the electrical contact surface when the electrical contact surface is at a touching voltage, wherein the method comprises sending a non-hazardous probing signal to the contact surface, wherein the probing signal comprises one probing pulse or a plurality of probing pulses forming a probing pulse train, and the probing pulse has a base voltage level and a probing voltage level which is above the base voltage level and equal to the touching voltage or a probing voltage level which is below the base voltage level and equal to the touching voltage; detecting an electrical response from the contact surface in response to the electrical probing signal, wherein the electrical response comprises electrical response signals; and determining from the electrical response signals whether there is possible living body contact at the electrical contact surface.