Differential Voltmeter Voltage Measurement Method

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Solution Overview

Problem

Existing voltage measurement methods require multiple voltmeters for each voltage, making them expensive and large, especially for applications like electronic motor protection switches, where multiple voltage measurements are necessary.

Innovation Solution

A method and device using a single differential voltmeter to measure two voltages by applying a known voltage potential and determining the voltages from measured differential voltages, allowing for efficient utilization of the voltmeter's range and simplifying the measurement of negative voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple independent voltmeters are used to measure multiple voltages, then measurement capability is improved, but device cost and size increase

Engineering Contradiction:
Improvevoltage measurement capabilityVSAvoidnumber of voltmeters
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes a single differential voltmeter perform multiple voltage measurement functions by sequentially connecting it to different voltage points through a switching unit. The voltmeter measures both the first voltage (relative to known potential) and the second voltage (relative to the first voltage), eliminating the need for multiple independent voltmeters and reducing device complexity while maintaining measurement capability.

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

2Device complexity

If a single differential voltmeter is used to measure multiple voltages, then device cost and size are reduced, but measurement range utilization becomes limited

Engineering Contradiction:
Improvenumber of voltmetersVSAvoidmeasuring range
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent extends the measuring range by changing the reference dimension. Instead of measuring both voltages relative to a common ground, the system measures the first voltage relative to a known potential and the second voltage relative to the first voltage. This differential measurement approach allows the single voltmeter to handle a wider range of voltage differences that would otherwise require multiple voltmeters with different ranges.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If negative voltages are measured using conventional methods, then measurement accuracy is maintained, but circuit complexity increases due to required converter circuits

Engineering Contradiction:
Improvenegative voltage measurement accuracyVSAvoidconverter circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a switching unit as an intermediary that connects the differential voltmeter to different voltage points at different times. The switching unit, controlled by a microcontroller, enables the voltmeter to measure negative voltages by appropriately connecting the measurement circuitry without requiring complex converter circuits, thus maintaining measurement precision while reducing overall system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP1994417B1Device and method for measuring a first voltage and a second voltage by means of a differential voltmeter
Publication Date: 2019.10.09 EATON INTELLIGENT POWER LTD
  • EP1994417B1 patent drawingFigure 1
  • EP1994417B1 patent drawingFigure 2
  • EP1994417B1 patent drawingFigure 3

AI summary

The invention relates to a method and a device for measuring a first voltage and a second voltage by means of a differential voltmeter (131). The differential voltmeter (131) comprises a first inlet and a second inlet and a known voltage potential is applied to the second inlet. The voltage measurement comprises the following steps; a first voltage is applied to a first inlet of the differential voltmeter, a first differential voltage is measured, the first voltage from the measured first differential voltmeter and the known voltage potential is determined, the second voltage is applied to the second inlet of the differential voltmeter, a second differential voltage is measured, and the second voltage from the measured second differential voltage and the previously determined first voltage is determined.