Portable Proving Unit for Contact and Non-Contact Voltage Verification

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Solution Overview

Problem

Technicians face challenges in verifying the operation of voltage measurement devices, especially in situations where no known voltage sources are available or have been de-energized, and existing solutions do not effectively support both contact and non-contact voltage measurement devices without galvanic contact.

Innovation Solution

A portable proving unit that provides a verified AC or DC voltage output, including a housing with a sensor receiving portion, an AC voltage source, AC-to-DC converter circuitry, mode selection switches, and a controller to selectively couple the voltage source to different ports, allowing for verification of both contact and non-contact voltage measurement devices without requiring galvanic contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional voltmeters or multimeters are used to measure AC voltage, then voltage measurement is achieved, but galvanic contact with the circuit is required which may damage insulation or require pre-installed terminals

Engineering Contradiction:
Improvevoltage measurement capabilityVSAvoidoperational convenience
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent introduces a field sense conductor as an intermediary element that generates an AC electric field within the housing. This field serves as a mediator between the proving unit and the non-contact voltage measurement device, allowing the device under test to detect the field and verify its non-contact measurement capability without requiring direct galvanic contact with external circuits

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The proving unit creates a simulated voltage field environment that copies the conditions of a live circuit. By generating an AC electric field through the field sense conductor and housing structure, it replicates the electromagnetic characteristics of energized conductors, enabling verification of non-contact measurement devices without needing actual power lines or live circuits

Inventive Principle:
Principle #26Copying

2Adaptability or versatility

If a proving unit provides both AC and DC voltage output modes, then versatility is improved, but device complexity increases due to additional circuitry

Engineering Contradiction:
Improvevoltage output mode flexibilityVSAvoidcircuit structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The proving unit achieves multi-functionality by incorporating both AC voltage source and DC voltage source within a single device architecture. The housing structure serves dual purposes as both the enclosure and the field sense conductor for AC mode, while the same housing with contact ports serves as the measurement interface for DC mode, allowing one device to verify both non-contact AC voltage detectors and contact DC voltmeters

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

Solution Approach 2:

The controller acts as an intermediary that manages the switching between AC and DC operational modes. It receives input from the mode selection switch and appropriately activates either the AC voltage source circuitry or the DC voltage source circuitry, coordinating the operation of different components to provide the selected voltage type without requiring complex manual circuit switching

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If visual and audible indicators are added to the proving unit, then operational status verification is improved, but device complexity increases

Engineering Contradiction:
Improveoperational status confirmationVSAvoidindicator system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The proving unit employs color changes of illumination indicators to communicate operational status. Different colors or illumination states of the indicator lights convey information about whether the device is in AC mode, DC mode, ready state, or error conditions, providing intuitive visual feedback without requiring complex display systems or text interfaces

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The controller serves as an intermediary that processes the operational state of the proving unit and translates it into appropriate indicator signals. It monitors the selected mode, the status of voltage sources, and system readiness, then activates the corresponding visual and audible indicators to communicate this information to the user in a simplified manner

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 convenient testing of voltage measurement devices by providing a portable, user-selectable voltage source with visual and audible indicators, ensuring the proving unit's operational status and allowing verification of both contact and non-contact devices in various applications.

Implementation Method 1

an alternating current (AC) voltage source that, in operation, is adapted to provide an AC voltage

Methodology Applied
Scientific EffectAlternating current:

Implementation Method 2

AC-to-DC converter circuitry that, in operation, is adapted to receive an AC voltage as input and outputs a DC voltage

Methodology Applied
Scientific EffectAC-to-DC conversion:

Implementation Method 3

at least one AC/DC switch that, in operation, is adapted to selectively electrically couple the AC output node of the AC voltage source either directly to the contact AC/DC positive port, or indirectly to the contact AC/DC positive port via the AC-to-DC converter circuitry

Methodology Applied
Scientific EffectElectrical coupling: Conduction (electrical)

Data Source

PatentEP3454065B1Proving unit for use with electrical test tools
Publication Date: 2021.05.05 FLUKE CORP
  • EP3454065B1 patent drawingFigure 1A
  • EP3454065B1 patent drawingFigure 1B
  • EP3454065B1 patent drawingFigure 2

AI summary

Systems and methods that provide a portable, verified voltage source that allows safe testing of separate contact and non-contact voltage measurement devices. A proving unit of the present disclosure selectively provides a known or specified direct current (DC) voltage, a contact alternating current (AC) voltage, and a non-contact AC voltage, which voltages may be fixed or may be user-selectable. The proving unit may include a visual indicator and/or an audible indicator that provides the user with an indication confirming that the proving unit is supplying the selected output voltage within the specifications of the proving unit, so the user will know that the proving unit is operating normally and is ready for testing the operation of a contact or non-contact voltage measurement device. If the proving unit cannot provide the specified voltage output, the indicator(s) provides a signal to the user that the proving unit is currently non-functional.