A MAGNETIC DOUBLE INTEGRAL

In a recent study of how the output voltage of a Hall plate is affected by the shape of the plate and the size of its contacts, U. Ausserlechner has come up with a remarkable double integral that can be viewed as a generalisation of the classical elliptic ‘arithmetic–geometric mean (AGM)’ integral. Here we discuss transformation properties of the integral, which were experimentally observed by Ausserlechner, as well as its analytical and arithmetic features including connections with modular forms.

Influence of magnetic concentrator on Hall effect based current sensor

Purpose The purpose of the paper is to clarify the influence of introducing magnetic concentrators on the performance of Hall effect based current sensors and to obtain dependencies of the sensor characteristics on the conductor position. Design/methodology/approach The finite element method and Comsol software are used for analysis of the three-dimensional magnetic field of the constructions of Hall effect based current sensor with different types of magnetic concentrators – closed-core (of rectangular and toroidal type) and open-core of toroidal type – with additional larger air gap. The Hall plate is also included in the model with its real dimensions and the magnetic flux density is obtained by integrating over its volume. Findings It has been found that there is dependence of the output signal (proportional to the magnetic flux density) of Hall effect based current sensor with both closed- and open-core magnetic concentrators on the position of the current carrying conductor. Distribution of the magnetic flux density and dependencies of its value in the Hall plate on the conductor position and on the additional air gap have been obtained. Optimization is carried out with respect to the additional air gap and cross-section dimensions of the concentrator. Originality/value Estimation of the influence of the introducing magnetic concentrators is made with respect to relationships between the output signal and conductor position for different constructions of the magnetic core of the concentrators.

Design and Evaluation of a Hall Sensor with Different Hall Plate Geometries in a 0.5µm CMOS Process

Un sensor Hall integrado fue diseñado y fabricado en un proceso CMOS ONC5N/F de 0.5μm provisto por MOSIS. Dentro del mismo, cuatro placas Hall con distintas geometrías fueron integradas con el objetivo de analizar su sensibilidad y resistencia desde -40°C hasta 165°C. Dentro del mismo chip también se integraron y diseñaron un amplificador y un sistema de rotación de corriente para remover su offset. Los resultados muestran una mayor sensibilidad en la placa Hall con forma de cruz y un comportamiento lineal del sensor dentro de su rango de operación.

An electronic gadget to control wheelchair motion using tongue gesture

Tongue drive system (TDS) is a tongue operated unobtrusive assistive technology,which can potentially provide people with severe disabilities with effective access and environment control.It translate user’s intentions into control commands by detecting and classifying their voluntary tongue motion utilizing a small permanent magnet,secured on the tongue and an array of magnetic sensors mounted on the mouth the magnetic sensor are nothing but hall effect sensors. a hall effect sensor is a transducerthat varies its output voltage in response to changes in magnetic field.in its simplest form the sensor operates as an analogue transducer, directly returning a voltage. With a known magnetic field, its distance from the hall plate can be determined. Wheel chair is made up of high torque geared DC motors, the motors direction can be changed through the set of instructions given from the hall effect sensor and the action of these instructions is already loaded into the microcontroller using embedded C programming. Complete system proposed in this paper has been designed around PIC microcontroller and a RF module. The design has been tested and result achieved confirms the design approach illustrated.