Multi-layer piezoelectric electrical energy transfer device

• US 6,229,247 B1
• Filed: 05/26/1999
• Issued: 05/08/2001
• Est. Priority Date: 11/09/1998
• Status: Expired due to Term

• Current Assignee: Face International Corp.
• Original Assignee: Face International Corp.
• Inventors: Bishop, Richard Patten
• Primary Examiner(s): BUDD, MARK OSBORNE
• Application Number:
  US09/318,966
• Time in Patent Office: 713 Days
• Field of Search: 310/328, 310/330-332, 310/340, 310/358, 310/359, 310/366
• US Class Current: 310/328
• CPC Class Codes: H10N 30/40 with electrical input and electrical output, e.g. functioning as transformers

Abstract

A multi-layered piezoelectric electrical energy transfer device has its input and output sides electrically isolated from each other. As a transformer, the device provides step-down voltage conversion while the output signal preserves the input signal frequency in a broad bandwidth. For telecommunications applications, the transformer can provide impedance matching with transmission lines, which minimizes line losses and echoes that seriously degrade high-speed data transmission. The piezoelectric transformer also provides a uniform voltage transformation ratio (V_out/V_in) over wide frequency ranges, and is adaptable for simultaneous audio and data signal telecommunications applications requiring wide bandwidth service.

Claims

1. An electrical energy transfer device, comprising:

a first electroactive ceramic layer having opposing electroded major faces which are disposed on the opposite sides of a first longitudinal plane;

said first electroactive ceramic layer being polarized normal to said first longitudinal plane such that upon application of a voltage across said opposing electroded major faces, said first electroactive ceramic layer deforms parallel to said first longitudinal plane;

a second electroactive ceramic layer having opposing electroded major faces which are disposed on the opposite sides of a second longitudinal plane;

said second electroactive ceramic layer being polarized normal to said second longitudinal plane such that upon application of a mechanical stress parallel to said second longitudinal plane, said second electroactive ceramic layer generates a voltage between said opposing electroded major faces;

a dielectric layer with first and second opposing major faces;

said first opposing major face of said dielectric layer being bonded to an opposing electroded major face of said first electroactive ceramic layer;

said second opposing major face of said dielectric layer being bonded to an opposing electroded major face of said second electroactive ceramic layer;

a first adhesive layer between said first face of said dielectric layer and one of said electroded major faces of said first electroactive ceramic layer;

wherein said first adhesive layer exerts a compressive stress on said first electroactive ceramic layer and said dielectric layer parallel to said first longitudinal plane;

a second adhesive layer between said second face of said dielectric layer and one of said electroded major faces of said second electroactive ceramic layer;

wherein said second adhesive layer exerts a compressive stress on said second electroactive ceramic layer and said dielectric layer parallel to said second longitudinal axis; and

a signal source for generating a signal of a first voltage and a first frequency;

said signal source being electrically connected across said electroded major faces of said first electroactive ceramic layer;

wherein said first electroactive ceramic layer is adapted to expand and contract parallel to said first longitudinal plane at said first frequency upon application of said first voltage across said electroded major faces;

and wherein said dielectric layer is adapted to expand and contract parallel to said first longitudinal plane upon said expansion and contraction of said first electroactive ceramic layer;

and wherein said second electroactive ceramic layer is adapted to expand and contract parallel to said second longitudinal plane upon said expansion and contraction of said dielectric layer;

and wherein said second electroactive ceramic layer is adapted to generate a second voltage across said electroded major faces upon said expansion and contraction of said second electroactive ceramic layer parallel to said second longitudinal plane;

and wherein said second voltage is of the same frequency as said first voltage.

2. The electrical energy transfer device of claim 1,

wherein said first and second electroactive ceramic layers, and said dielectric layer are of substantially the same shape in said first and second longitudinal planes, said shape being a rectangle having a length and a width;

and wherein a ratio between said length and said width is a non-integer.

3. The electrical energy transfer device of claim 1, The electrical energy transfer device of claim 1,

wherein said first and second electroactive ceramic layers, and said dielectric layer are of substantially the same shape in said first and second longitudinal planes, said shape being an ellipse having a major axis and a minor axis;

and wherein a ratio between said major axis and a minor axis is greater than one.