Modular Current Transducer Coil Assembly for Flexible Measurement Range

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Solution Overview

Problem

Existing electrical current transducers are often costly to produce and install, lack versatility in connection and mounting arrangements, and may not provide accurate and reliable measurements while being compact and robust.

Innovation Solution

The proposed electrical current transducer features a housing with a magnetic core and a magnetic field sensing device, including a connector interface with latching elements for easy mounting and a conductor module with adjustable conductor coil portions for varying measurement ranges, all designed for economical production and installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional current transducer designs are used, then measurement function is achieved, but manufacturing cost and installation cost are high

Engineering Contradiction:
Improvemanufacturing costVSAvoidmeasurement accuracy
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The current transducer is divided into modular components: a magnetic core module with pre-mounted sensing device, and a separate connector module. This segmentation allows independent optimization of each module for cost-effective manufacturing while maintaining measurement accuracy through precise magnetic circuit design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The magnetic core is designed with universal mounting features that accommodate different sensing devices (Hall effect sensors, fluxgate sensors) and support multiple connection types. This multi-functionality reduces manufacturing costs through standardized production while maintaining reliable measurements across different application scenarios.

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

2Adaptability or versatility

If traditional current transducer designs are used, then measurement function is achieved, but connection and mounting arrangements lack versatility

Engineering Contradiction:
Improveconnection and mounting arrangementsVSAvoidstructure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connector module integrates multiple connection interfaces (soldering terminals, screw terminals) and mounting options (through-hole mounting, surface-mount) into a single standardized component. This universal design provides versatility for different installation scenarios without increasing overall device complexity.

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

Solution Approach 2:

The magnetic core incorporates adjustable positioning features that allow the sensing device to be dynamically positioned within the magnetic circuit to optimize measurement accuracy for different conductor configurations, while the standardized connector provides static universal mounting capability.

Inventive Principle:
Principle #15Dynamics

3Volume of moving object

If compact design is implemented, then device size is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improvedevice sizeVSAvoidassembly precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The compact current transducer is segmented into a small magnetic core module and a separate connector module. This segmentation allows the magnetic core to be manufactured with high precision for compactness, while the connector module provides tolerance compensation that reduces overall assembly precision requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connector module acts as an intermediary between the precision magnetic core and the external circuitry. It provides mechanical tolerance compensation and electrical connection stability, allowing the compact magnetic core to maintain high manufacturing precision without requiring equally precise external mounting structures.

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

This solution enables a versatile, cost-effective, and accurate current transducer that is easy to install and provides reliable operation, while being compact and robust, thus addressing the limitations of existing technologies.

Implementation Method 1

The magnetic flux generated by the electrical current flowing in the primary conductor is concentrated by the magnetic core and is representative of the primary current

Methodology Applied
Scientific EffectMagnetic flux concentration: Magnetic Field

Implementation Method 2

Secondary coils are also employed in current transducers of the open-loop type, but as pick-up coils that measure the magnetic field concentrated in the magnetic core in a transformer effect

Methodology Applied
Scientific EffectTransformer effect: Electromagnetic Induction

Implementation Method 3

the magnetic field sensor is connected in a feedback loop to a compensation coil, also generally called a secondary coil, that is typically wound around a portion of the magnetic core in order to generate a compensation current that tends to cancel the magnetic field generated by the primary conductor

Methodology Applied
Scientific EffectMagnetic field cancellation: Magnetic Field

Data Source

PatentEP4212887B1Current transducer
Publication Date: 2025.06.04 LEM INT SA
  • EP4212887B1 patent drawingFigure 1a~1e
  • EP4212887B1 patent drawingFigure 2a
  • EP4212887B1 patent drawingFigure 2b

AI summary

Electrical current transducer for measuring an electric current in a primary conductor, including a housing (4), a magnetic core (6) surrounding a central aperture (9) through which the primary conductor extends, and a magnetic field sensing device (8) comprising connection terminals (18), the housing comprising a magnetic core receiving cavity (22) in which the magnetic core is lodged and a connecting interface portion (25) in which the magnetic field sensing is lodged, the transducer further comprising a conductor module (5) comprising an insulating support (12) in which U shaped conductor coil portions (3) are lodged, the insulating support further comprising latching elements (28a) configured to engage complementary latching shoulders (28b) provided on the housing for securing the conductor module around a branch of the current transducer. The conductor mounting channels comprise clasp protrusions (27) configured to clasp the U shaped conductor coil portions in the conductor mounting channels, a variable number of conductor coil portions being insertably mountable to the insulating support, the number selected according to the operating range of the current transducer.