Method and apparatus for high voltage gain using a magnetostrictive-piezoelectric composite

• US 20050194863A1
• Filed: 03/08/2005
• Published: 09/08/2005
• Est. Priority Date: 03/08/2004
• Status: Active Grant

• Current Assignee: Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Original Assignee: Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Inventors: Dong, Shuxiang, Li, Jiefang, Viehland, Dwight Douglas
• Granted Patent: US 7,256,532 B2
• Time in Patent Office: Days
• US Class Current: 310/311
• CPC Class Codes: H10N 30/00 Piezoelectric or electrostrictive devices integrated devices or assemblies of multiple devices H10N39/00
• CPC Class Codes: H10N 30/8554 Lead-zirconium titanate [PZT] based
• CPC Class Codes: H10N 35/00 Magnetostrictive devices integrated devices or assemblies of multiple devices H10N39/00
• CPC Class Codes: H10N 35/85 Magnetostrictive active materials

Abstract

A method and apparatus attains high voltage gain by using a composite structure of an elastic section of piezoelectric layers bonded between magnetic and electric sections of magnetostrictive layers, with a harmonic magnetic field being applied along the layers at a mechanical resonance frequency of the composite structure, through coils around the laminate carrying current, such as to produce a continuity of both magnetic and electric flux lines, and achieving a high voltage output.

Claims

1. A magneto-electric transformer, comprising:

a top section comprised of one or more magnetostrictive layers;

a bottom section comprised of one or more magnetostrictive layers; and

an elastic section comprised of one or more piezoelectric layers, said elastic section being sandwiched with a mechanical bond between said magnetic section and said electric section to form a composite structure of parallel layers,

wherein a harmonic ac magnetic field is applied along the parallel layers of the composite at a mechanical resonance frequency of the bonded composite structure, there being a continuity of both magnetic and electric flux lines across said sections.

2. A magneto-electric transformer as in claim 1, wherein said layers are rings and said transformer is a toroid.

3. A magneto-electric transformer as in claim 1, wherein said layers are longitudinal and said transformer is a rectangular plate.

4. A magneto-electric transformer as in claim 3, wherein said magnetostrictive layers are longitudinally-magnetized Terfenol-D layers and said peizoelectric layers are longitudinally poled Pb(Zr,Ti)O₃.

5. A magneto-electric transformer as in claim 4, wherein the piezoelectric layers are longer than the magnetostrictive layers.

6. A magneto-electric transformer as in claim 4, wherein a dc magnetic bias is applied to said ac harmonic magnetic field.