A broadband magneto-electric transducer using a composite material

Abstract

This article deals with the application of a composite material as a magneto-electric transducer. The composite, which has both magneto-strictive and piezo-electric properties was developed at Philips' Research Laboratories. A transducer consisting of a piece of composite appears to be a suitable replacement for e.g. Hall devices, especially in AC applications. It needs only two electrical contacts and has a flat frequency response from a few Hz up to 650 kHz, where mechanical resonance occurs. Several calculations and experiments were carried out on the transducer and its electronic analogon, as well as on the measuring set-up, which had to produce a calibrated magnetic field. The results of the measurements on frequency response, transfer characteristics, internal impedance, temperature dependence and noise are discussed. The construction of a magnetic field probe using the composite is described and finally some other applications are given.