Capacitive Voltage Probe for Small Wires

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Solution Overview

Problem

Existing voltage detecting probes have a large external form due to magnetic cores, clamping or sandwiching mechanisms, and magnets, making it difficult to attach them to small-diameter single wires, especially when other wires are closely bundled.

Innovation Solution

A voltage detecting probe with a shield barrel and a detection electrode that can move relative to the shield barrel, allowing capacitive coupling with the measured wire without direct contact, and a measuring device that includes a voltage detector, generator, and processor to accurately measure the wire's voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If magnetic cores, clamping mechanisms, or magnets are disposed in the periphery of detection electrodes, then voltage detection capability is achieved, but the external form becomes large making it difficult to attach to small-diameter wires

Engineering Contradiction:
Improvevoltage detection capabilityVSAvoidexternal form size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent extracts and removes the magnetic core, clamping mechanism, and peripheral magnets from the detection probe structure. Instead, it uses a simple conductive shield barrel with a detection electrode that makes direct contact with the measured wire, achieving voltage detection without the bulky components that previously dominated the probe's external form.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical clamping and magnetic holding systems with a simpler direct-contact approach. The detection electrode physically contacts the measured wire to establish electrical connection, eliminating the need for complex mechanical clamping mechanisms and magnetic components, thereby reducing the overall size of the probe.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Volume of moving object

If the detection probe is made compact for small-diameter wires, then attachability to bundled wires is improved, but noise shielding capability may be reduced

Engineering Contradiction:
Improveprobe sizeVSAvoidnoise interference
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a conductive shield barrel as an intermediary structure between the detection electrode and the external environment. This shield barrel serves dual purposes: it maintains a compact probe size while simultaneously providing electromagnetic shielding to protect the detection electrode from noise interference, thus resolving the contradiction between compactness and noise protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If manual intervention is required to maintain measurement state, then measurement control is precise, but ease of operation is reduced

Engineering Contradiction:
Improvemeasurement controlVSAvoiduser-friendliness
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent implements a self-maintaining measurement system where the detection electrode, upon contacting the measured wire, automatically establishes and maintains the measurement state without requiring continuous manual intervention. The shield barrel structure itself helps maintain the contact state, allowing the system to serve itself by preserving the measurement condition naturally once initiated.

Inventive Principle:
Principle #25Self-service

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 reliable and easy voltage measurement of small-diameter wires in close proximity to other conductors, while reducing noise interference and improving user-friendliness by maintaining the measurement state without manual intervention.

Implementation Method 1

the front end surface is capable of capacitive coupling, via the insulating covering, with the measured wire that has been inserted in the insertion concave

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

A voltage detecting probe with a shield barrel and a detection electrode that can move relative to the shield barrel, allowing capacitive coupling with the measured wire without direct contact, and a measuring device that includes a voltage detector, generator, and processor to accurately measure the wire's voltage

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP3115792B1Voltage detecting probe and measuring device
Publication Date: 2025.04.30 HIOKI DENKI KK
  • EP3115792B1 patent drawingFigure 1~2
  • EP3115792B1 patent drawingFigure 3~4
  • EP3115792B1 patent drawingFigure 5~6

AI summary

A voltage detecting probe (1) includes: a shield barrel (21) that is a barrel-shaped member made of an electrically conductive material and has an insertion concave (33) for inserting a wire formed in a front end thereof by cutting away an outer circumferential wall at the front end along a direction perpendicular to an axis; and a detection electrode (23) that is formed of a cylindrical member made of an electrically conductive material, whose front end surface (23a) and outer circumferential surface are covered with an insulating covering (24), and is housed inside the shield barrel (21) and capable of moving relative to the shield barrel (21) along the axis direction. When the detection electrode (23) has been moved relative to the shield barrel (21) and the front end surface (23a) is positioned at the insertion concave (33), the front end surface (23a) becomes capacitively coupled, via the insulating covering (24), with a wire inserted in the insertion concave (33).