Electronic Energy Meter Based on a Tunnel Magnetoresistive Effect (TMR) Current Sensor.

Enrique García Vidal,Diego Ramírez Muñoz,Sergio Iván Ravelo Arias,Jaime Sánchez Moreno,Susana Cardoso,Paulo Freitas,Ricardo Ferreira

doi:10.3390/ma10101134

Abstract

In the present work, the design and microfabrication of a tunneling magnetoresistance (TMR) electrical current sensor is presented. After its physical and electrical characterization, a wattmeter is developed to determine the active power delivered to a load from the AC 50/60 Hz mains line. Experimental results are shown up to 1000 W of power load. A relative uncertainty of less than 1.5% with resistive load and less than 1% with capacitive load was obtained. The described application is an example of how TMR sensing technology can play a relevant role in the management and control of electrical energy.

Highlights

Tunneling magnetoresistance (TMR) sensing is the fourth generation of magnetoresistive magnetic sensing technology after galvanomagnetic, anisotropic (AMR), and giant (GMR) technologies.The galvanomagnetic effect was achieved in semiconductors having a thickness greater than their length [1]
A resistive variable load was built to change the change the power delivered to the loadthe from 0 towas
An energy meter is presented based on a tunneling magnetoresistance (TMR) current sensor with good linearity and relative

Summary

Introduction

Tunneling magnetoresistance (TMR) sensing is the fourth generation of magnetoresistive magnetic sensing technology after galvanomagnetic, anisotropic (AMR), and giant (GMR) technologies. The galvanomagnetic effect was achieved in semiconductors having a thickness greater than their length [1]. Better sensitivities were achieved using semiconductor materials such as InSb with Te as the preferred dopant atom [2]. AMR sensing technology was based on materials derived from binary and tertiary alloys of Fe, Ni, and Co, such as permalloy, deposited over a Si substrate. With these structures, AMR-based sensors achieved 2–4% of magnetoresistance variation, requiring a specific. With GMR sensing technology, 70% of magnetoresistance relative variation was reached [4], in the most applications the variation was between 4% and

Methods

Results

Conclusion