Stacked Current Sensor Layout for Low-Frequency Noise Rejection
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Solution Overview
Problem
Existing current sensors face challenges in accurately measuring low-frequency current due to noise interference and require significant mounting space, especially when applied to power lines with commercial frequencies of 50 Hz or 60 Hz, as they are susceptible to ambient noise and difficult to miniaturize without compromising sensitivity.
Innovation Solution
The current sensor is designed with a compact structure where the sensor unit and circuit unit are aligned or stacked perpendicularly to the power line, minimizing parallel transmission lines and using a shielding case to reduce noise interference, and incorporating multiple coils connected in series or parallel to enhance signal detection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional current sensor designs are used, then mounting space is sufficient, but noise interference increases and measurement precision deteriorates
Solution Approach 1:
The patent transitions from a planar arrangement to a three-dimensional stacked configuration where the sensor unit and circuit unit are positioned on opposite sides of the power line, separated by insulation layers. This spatial separation in the vertical dimension reduces electromagnetic coupling and noise interference while maintaining measurement precision.
Solution Approach 2:
The patent introduces an insulation layer as an intermediary between the sensor unit and circuit unit, and between the power line and sensor unit. This intermediary structure acts as a shield against electromagnetic noise while allowing magnetic field penetration for current detection.
2Object-affected harmful factors
If sensor unit and circuit unit are separated, then noise interference is reduced, but device complexity increases
Solution Approach 1:
The patent combines the sensor unit and circuit unit into a single integrated current sensor device with a unified external structure. Although internally separated for noise reduction, the components are merged into one compact unit that can be installed as a single component on the power line.
Solution Approach 2:
The circuit unit is nested within the same housing structure as the sensor unit, with both units stacked vertically around the power line. This nested arrangement achieves spatial separation for noise reduction while maintaining a compact integrated form factor.
3Measurement precision
If multiple coils are used, then signal detection efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent divides the sensing function into multiple discrete coils (first coil and second coil) that can be independently manufactured and then assembled. Each coil is formed on separate conductor layers, allowing modular manufacturing while achieving enhanced signal detection through multiple sensing elements.
Solution Approach 2:
The multiple coils serve dual functions: individually detecting magnetic fields for current measurement and collectively providing redundancy and enhanced signal strength. The same coil structure performs both sensing and noise cancellation functions.
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 configuration improves signal detection efficiency and minimizes noise interference, allowing accurate measurement of low-frequency currents while occupying minimal space, suitable for various power line configurations.
Implementation Method 1
a sensor unit including at least one coil... configured to output a detection signal from the sensor unit
Data Source
AI summary
A current sensor includes a sensor unit including at least one coil formed of a substrate including an insulating layer and conductor layers sandwiching the insulating layer, a plurality of via holes each including a conductive film on an inner wall penetrating the substrate, and a line patterning formed on the conductor layers to electrically connect the plurality of via holes. The sensor also includes a circuit unit disposed in proximity to the sensor unit on the substrate and configured to output a detection signal from the sensor unit to an outside, and a connection unit electrically connecting the sensor unit and the circuit unit. A width of each of the sensor unit and the circuit unit in a transverse direction of the power line is equal to or less than a width of the power line. The circuit unit overlaps the power line.