Electrical characteristics of high power piezoelectric transformer for 28 W fluorescent lamp

In order to drive the T5 fluorescent lamp developed recently, contour vibra tion mode piezoelectric transformers with the composition of Pb(Ni-1/2, W-1 /2)O-3-Pb(Mn-1/3, Nb-2/3)O-3-Pb(Zr, Ti)O-3 (PNW-PMN-PZT) were fabricated to the modified filter structure. The composition ceramics were consolidated to the square plate using cold isostatic pressing and the ring/dot electrod es were designed on it for the impedance matching of the fluorescent lamp. Electrical properties and characteristic temperature rise caused by the vib ration were measured. Efficiencies of the transformers proved to be above 9 0%. A 28 W fluorescent lamp was successfully driven by all of the transform ers. The transformer with ring/dot electrode ratio of 1.83 showed the best properties in terms of output power, efficiency and characteristic temperat ure rise, 30.95 W, 97.5% and 8.3 degreesC, respectively. (C) 2001 Elsevier Science B.V. All rights reserved.