Abstract: A non-contact exciter based on electro-magnetic eddy-current technique is developed. It has the advantages of high precision of measurement, low noise, simple structure and easy operation. A new exciting technique is developed for vibration tests of plates with infinite size or with fixed boundaries.The principles, pcrformcnces and characteristics of excited conductive plates (magnetic or nonmagnetic matctials) are illustraled in this paper. An analysis of the magnetic circuit and the design of the structure are described. Finally, the vibration tesrs of the circular and square plates are inlroduced.It is shown that the results are satisfactory.

Key words: plate with infinite size, exciting, testing cquipncn