Voltage Tester Using Operator Body as Ground Reference

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Solution Overview

Problem

Existing voltage testers are not designed for safe and easy operation in flooded areas, posing risks to rescue workers and energy supply employees due to unreliable ground potential connections and complex handling requirements, which can only be performed by qualified electricians.

Innovation Solution

A voltage test device with an operator connection point and a liquid connection point, allowing the operator to be part of the circuit, maintaining a safe distance to detect voltages independently of ground potential, using conductive materials and integrated resistance for current limitation and measurement, with a microcontroller for threshold comparison and warning signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a terminal connected to ground potential is used for voltage testing, then voltage measurement is possible, but the test result is questionable due to unreliable ground potential information and the device can only be operated by qualified electricians

Engineering Contradiction:
Improvetest result reliabilityVSAvoidoperation complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The voltage tester uses the operator's body as part of the measurement circuit, eliminating the need for external ground connection. The operator connects to the device via conductive areas on the handle, and the measurement circuit is completed through the operator's body resistance to the liquid being tested, making the device self-sufficient and independent of external ground potential references

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The device serves multiple functions: it measures voltage, limits current through integrated resistance, provides visual warnings, and uses the operator's body as both the measurement path and the reference potential, replacing the need for separate ground connection equipment and making it usable by non-qualified personnel

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a cable-connected terminal with ground potential connection is used, then voltage testing can be performed, but handling is complicated by cable unwinding, ground potential finding, and terminal attachment

Engineering Contradiction:
Improveground potential connectionVSAvoidhandling complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention extracts and eliminates the cumbersome cable and terminal connection components from the measurement system. Instead of requiring external ground connection equipment, the device uses the operator's body as the reference potential, removing all associated handling steps for cable management, ground finding, and terminal attachment

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The operator's body serves as the built-in ground reference and measurement path, making the device self-sufficient. The conductive areas on the handle provide direct electrical connection to the operator, eliminating the need for separate ground connection equipment and simplifying operation to merely holding the device

Inventive Principle:
Principle #25Self-service

3Reliability

If commercial phase testers with glow lamps are used, then voltage detection is possible, but they are not designed for rough use in emergencies and are not intended for testing voltages in liquids

Engineering Contradiction:
Improvevoltage detection capabilityVSAvoidsuitability for flooded areas
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention changes the fundamental measurement parameter from voltage-only detection to combined voltage and current measurement through the operator's body. This allows the device to safely measure voltages in liquids by limiting current through integrated resistance, adapting the measurement approach to suit emergency flooded area conditions where commercial phase testers cannot be used

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If the operator becomes part of the measurement circuit, then ground potential connection is eliminated, but current flow through the operator's body must be limited to ensure safety

Engineering Contradiction:
Improveindependence from ground potentialVSAvoidcurrent flow through operator
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The device incorporates high integrated resistance values before the measurement is taken, ensuring that current flow through the operator's body is limited to safe levels. This pre-built protection cushioning ensures that even if the operator completes the circuit to the liquid, the current remains below dangerous thresholds

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

Solution Approach 2:

The integrated resistance acts as an intermediary element between the voltage source in the liquid and the operator's body. It mediates the current flow, allowing voltage measurement while limiting current to safe levels, thus protecting the operator while enabling the measurement function

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables safe and independent voltage testing in flooded areas, protecting operators from dangerous currents by limiting current intensity and providing reliable voltage information, ensuring operational safety without requiring ground potential dissipation, suitable for use by non-qualified personnel.

Implementation Method 1

during operation the voltage to be tested causes a current flow through the device and the body of the operator

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The total resistance between the liquid connection point and the operator connection point is advantageously chosen to be at least so large that the current in the operator connection point is limited to 1 mA or less

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP2189797B1Voltage testing apparatus for fluids
Publication Date: 2018.07.04 ESWE VERSORGUNGS AG
  • EP2189797B1 patent drawingFigure 1
  • EP2189797B1 patent drawingFigure 2

AI summary

The device has a user connector (3) provided with an electrically conductive region that electrically connects the device with a body part i.e. hand, of a user. A fluid connector (1) is provided with an electrically conductive region that electrically connects the device with fluid. Electrical voltage to be tested causes a current flow through the device and the body part of the user, during operation. The conductive regions of the connectors exhibit a distance of 0.50 m from each other. An operation and display unit (5) is arranged between the connectors, and includes LEDs (7-10). An independent claim is also included for a method for testing electrical voltage between electrical conductive fluid and a location of a user.