PCB Measurement Transformer With Integrated Core for Precise Current Sensing
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Solution Overview
Problem
Existing flow valve current sensors face challenges in achieving industrial reproducibility and high cost due to variations in material and structural characteristics, particularly in measuring high currents where demagnetization currents are difficult to manage effectively.
Innovation Solution
A measuring transformer is integrated into a printed circuit board with a magnetic core, utilizing plated-through holes for primary and secondary windings, ensuring precise control over electrical characteristics and reducing material costs by integrating the magnetic core directly into the circuit board.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional windings are used in flow valve current sensors, then the sensor can measure current, but industrial reproducibility is poor and cost is high due to variations in material and structural characteristics
Solution Approach 1:
The patent replaces conventional mechanical windings with printed circuit board (PCB) traces to form the primary and secondary windings. This substitution eliminates variations in winding parameters such as turn count, wire diameter, and winding tension that plague traditional mechanical winding methods. The PCB-based windings provide consistent electrical characteristics across production batches, significantly improving industrial reproducibility while reducing manufacturing cost through automated PCB fabrication processes.
Solution Approach 2:
The patent merges the magnetic core directly with the printed circuit board by integrating the core into the PCB structure. This integration eliminates the need for separate mounting operations and ensures precise positioning and coupling between the magnetic core and the PCB windings. The merged structure reduces assembly complexity and variability, further enhancing manufacturing precision and reproducibility.
2Reliability
If conventional windings are used, then the sensor structure can be assembled, but material and structural variations lead to poor reproducibility
Solution Approach 1:
The patent replaces mechanical windings with PCB traces, which provide consistent electrical characteristics and eliminate variations in winding parameters. This substitution significantly improves measurement consistency and reliability across different production batches while simplifying the overall device structure by integrating the windings directly into the PCB substrate.
Solution Approach 2:
The integration of the magnetic core with the PCB structure creates a unified, compact design that eliminates separate components and assembly steps. This merging reduces structural complexity while ensuring consistent magnetic coupling, thereby improving measurement reliability without increasing device complexity.
3Measurement precision
If high demagnetization currents are required, then magnetic flux can be compensated, but it becomes difficult to manage effectively in high current measurements
Solution Approach 1:
The PCB-based secondary winding allows for precise control and optimization of the turns ratio between primary and secondary windings. By carefully designing the trace geometry and number of turns during PCB fabrication, the transformer achieves the optimal turns ratio for efficient magnetic flux compensation. This precise parameter control enables effective demagnetization with lower currents, making it easier to manage in high current measurement applications while maintaining measurement accuracy.
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 design improves industrial reproducibility and reduces costs by providing precise current measurement with minimal demagnetization current requirements, maintaining sensitivity and accuracy across a wide temperature range while being resistant to electromagnetic interference.
Implementation Method 1
A flow valve current sensor utilizes the property of a magnetic material forming a magnetic core to saturate above a certain level of magnetic excitation
Implementation Method 2
a square wave excitation voltage Vex across the terminals of an excitation winding 3 wound around a magnetic core 4. The excitation current Iex flowing in the excitation winding 3
Implementation Method 3
at least one secondary winding opposite the magnetic circuit capable of producing a feedback magnetic field
Data Source
Figure 1~3
Figure 4
Figure 5~7
AI summary
Measurement transformer including a printed circuit board (40) and a magnetic core (13), the printed circuit board comprising an insulating layer (43), a primary through-assembly comprising first primary metallized holes (47) and second primary metallized holes (48) that pass through the insulating layer (43), the primary through-assembly forming a portion of a primary winding of the transformer, said primary winding comprising a single turn, the printed circuit board further including a secondary through-assembly comprising first secondary metallized holes (56) and second secondary metallized holes (57) that pass through the insulating layer (43), the secondary through-assembly forming a portion of a secondary winding of the transformer, said secondary winding comprising a plurality of turns connected in series, the magnetic core lying within a thickness of the printed circuit board (40).