Scientific Research of the Institute of Mathematics and Computer Science 3(11) 2012, 81-92 DC MAGNETIC FIELD GENERATOR WITH SPATIAL COILS ARRANGEMENT Adam Kozlowski , Stan Zurek 2 1 Magneto Ltd., Odlewnikow 43, 42-200 Czestochowa, Poland 2 Megger Instruments Ltd, Archcliffe Road, Dover, CT17 9EN, United Kingdom adam.kozlowski@magneto.pl, stan.zurek@megger.com Abstract. This paper is dedicated to the effect of the number of excitation coils of a DC magnetic field generator with magnetic core on uniformity of flux density in an air gap. The advantages and drawbacks of the air gap surrounded by yoke elements with coils were analysed. Introduction Many industrial or laboratory research processes require the presence of a mag- netic field, for formation or measurement of magnetic properties. Permanent magnets are an easily accessible source of a magnetic field. Espe- cially widespread are neodymium magnets characterized by large values of energy densities. Just a single magnet is in fact a generator of a constant (DC) magnetic field. One can make a more complicated construction of a magnetic field generator (MFG) with a few magnets as well as from magnets combined with a magnetic core to increase the magnetic field strength in the volume of interest - often an air gap. The main benefit of MFG based on magnets is the generation of a magnetic field without an energy supply. The drawback is the lack of possibility to regulate and/or switch off the magnetic field. Another MFG construction is a magnetic core with an air gap and excitation windings or coils as sources of magnetomotive force (MMF). This solution ena- bles full control of magnetic field strength in the air gap between two poles of the magnetic circuit. There are many configurations of electromagnetic field generators (EMFG). They differ by arrangement of excitation coils, their quantity and core shape, and so on. As a novel design could be considered an EMFG characterized by a more complex core design - with coil arrangement spatially. An analysis of results was conducted on the basis of measurements carried out on a test model of such an EMFG with spatial coils arrangement in order to investigate usefulness of this kind of generator for industrial and laboratory applications.