0000000000084302
AUTHOR
Jaime Sánchez Moreno
Electronic Energy Meter Based on a Tunnel Magnetoresistive Effect (TMR) Current Sensor
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.
A Non-Invasive Thermal Drift Compensation Technique Applied to a Spin-Valve Magnetoresistive Current Sensor
A compensation method for the sensitivity drift of a magnetoresistive (MR) Wheatstone bridge current sensor is proposed. The technique was carried out by placing a ruthenium temperature sensor and the MR sensor to be compensated inside a generalized impedance converter circuit (GIC). No internal modification of the sensor bridge arms is required so that the circuit is capable of compensating practical industrial sensors. The method is based on the temperature modulation of the current supplied to the bridge, which improves previous solutions based on constant current compensation. Experimental results are shown using a microfabricated spin-valve MR current sensor. The temperature compensati…
Fractional Modeling of the AC Large-Signal Frequency Response in Magnetoresistive Current Sensors
Fractional calculus is considered when derivatives and integrals of non-integer order are applied over a specific function. In the electrical and electronic domain, the transfer function dependence of a fractional filter not only by the filter order n, but additionally, of the fractional order α is an example of a great number of systems where its input-output behavior could be more exactly modeled by a fractional behavior. Following this aim, the present work shows the experimental ac large-signal frequency response of a family of electrical current sensors based in different spintronic conduction mechanisms. Using an ac characterization set-up the sensor transimpedance function is obtain…
Diseño, fabricación, caracterización y estudio de aplicabilidad de un sensor de corriente eléctrica basado en tecnología válvula de espín y un detector de temperatura basado en Rutenio
El efecto magnetorresistivo (MR) es el cambio de resistencia eléctrica de un material conductor cuando éste es sometido a un campo magnético externo. Este fenómeno se conoce desde 1856 (Lord Kelvin) como efecto magnetorresistivo anisotrópico. Se trata, en general de un fenómeno de baja intensidad donde la variación de resistencia es del 3%. En los años 80, los sensores basados en el efecto AMR eran aplicados como cabezas lectoras en los sistemas de almacenamiento de datos. A mediados de esa misma década se desarrolló la tecnología capaz de fabricar capas nanométricas permitiendo el estudio y desarrollo de nuevos materiales. En 1988 dos grupos de investigación descubrieron materiales donde e…
A new gas sensor electronic interface with generalized impedance converter
A new gas sensor conditioning circuit that allows a direct resistance-to-frequency conversion, as well as the procedure for the design, is presented. The generalized impedance converter (GIC) proposed is configured as a variable capacitor connected with the capacitor timing terminal of an astable multivibrator implemented by a PSoC (programmable system on chip) microcontroller device. The GIC effective input impedance, which is controlled by the gas sensor resistance, controls the astable output frequency. Good correlation of the experimental output frequency, which depends on the gas concentration, is achieved. The circuit is a simple gas sensor digital interface with frequency output.