Piezoelectric transformer with multiple output

• US 5,892,318 A
• Filed: 01/02/1997
• Issued: 04/06/1999
• Est. Priority Date: 01/02/1997
• Status: Expired due to Fees

• Current Assignee: CTS Corporation
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Dai, Xunhu, Phillips, James R.
• Primary Examiner(s): Budd, Mark O.
• Assistant Examiner(s): WILLIAMS, TIMOTHY A J
• Application Number:
  US08/775,531
• Time in Patent Office: 824 Days
• Field of Search: 310/358, 310/366, 310/357, 310/359, 310/367, 310/328
• US Class Current: 310/358
• CPC Class Codes: H10N 30/40 with electrical input and electrical output, e.g. functioning as transformers

Abstract

A piezoelectric ceramic transformer made from a piezoelectric ceramic material stacked in a multilayer package which has a driving section 502 formed by alternately stacking piezoelectric ceramic layers polarized in a direction of thickness of the piezoelectric plate. The driving section 502 has internal interdigitated electrode layers 504A, 504B for causing piezoelectric vibration by a driving voltage applied to an input terminal (Vin). A first driven section 506, also made from piezoelectric ceramic layers polarized in the longitudinal direction of the piezoelectric plate, for generating a first output voltage (Vout1) at a first output by the piezoelectric vibration transmitted from the driving section 502. A second driven section 510, made from piezoelectric ceramic layers polarized in the thickness direction of the piezoelectric plate, for generating a second output voltage (Vout2) at a second output by the piezoelectric vibration transmitted from the driving section 502. Thus, a piezoelectric ceramic multilayer transformer with a multiple output is created.

Claims

1. A piezoelectric ceramic transformer with multiple driven sections providing multiple distinct output voltages, comprising:

a piezoelectric plate made of a piezoelectric ceramic material having a combination Rosen-Transformer/Stack-Transformer geometry and comprising;

a driving section formed by alternately stacking a plurality of piezoelectric ceramic layers polarized in a direction of thickness of the piezoelectric plate, the driving section having internal interdigitated electrode layers for causing piezoelectric vibration by a driving voltage applied to an input terminal;

a first independent driven section longitudinally adjacent to the driving section comprising a plurality of piezoelectric ceramic layers polarized in the longitudinal direction of the piezoelectric plate, for generating a first output voltage at a first output terminal on a first major output surface by the piezoelectric vibration transmitted from the driving section;

a second independent driven section vertically adjacent to the driving section comprising a plurality of piezoelectric ceramic layers polarized in the thickness direction of the piezoelectric plate, for generating a second output voltage at a second output terminal on a second major output surface by the piezoelectric vibration transmitted from the driving section;

the first output voltage and the second output voltage are distinct defining a transformer with multiple driven sections providing multiple distinct output voltages.

2. The transformer of claim 1, further comprising a third independent driven section vertically adjacent to the driving section comprising a plurality of piezoelectric ceramic layers polarized in the thickness direction of the piezoelectric plate, for generating a third output voltage at a third output terminal on a third major output surface by the piezoelectric vibration transmitted from the driving section, and the third output voltage is distinct from the first output voltage and the second output voltage.

3. The transformer of claim 2, further comprising isolation layers between the driving section and the second and third driven sections.

4. The transformer of claim 1, wherein the driving section includes:

a first external electrode formed on at least a first major surface of the driving section of the piezoelectric plate and connected to a first set of alternate interdigitated internal electrode layers and to the first input terminal; and

a second external electrode formed on at least a second major surface of the driving section of the piezoelectric plate and connected to a second set of alternate interdigitated internal electrode layers and to a ground.

5. The transformer of claim 1, wherein overall power output is increased by electrically connecting at least the first output voltage and the second output voltage in parallel.

6. The transformer of claim 1, wherein overall voltage output is increased by electrically connecting at least the first output voltage and the second output in series.

7. The transformer of claim 1, wherein the transformer is a reciprocal device and the input and outputs can be reversed.

8. The transformer of claim 1, wherein the piezoelectric ceramic material comprises at least one member of the group consisting of lead titanate, lead titanate-lead zirconate (PbZrO3-PbTiO3), barium titanate, lithium niobate, and equivalents thereof.

9. The transformer of claim 1, wherein the driving section comprises a top driving section and a bottom driving section.

10. The transformer of claim 1, in which the transformer is at least one of a step-up and step-down type transformer.

11. A piezoelectric ceramic transformer with multiple driven sections providing multiple distinct output voltages, comprising:

a piezoelectric plate made of a piezoelectric ceramic material having a combination Rosen-Transformer/Stack-Transformer geometry and comprising;

a driving section formed by alternately stacking a plurality of piezoelectric ceramic layers polarized in a direction of thickness of the piezoelectric plate, the driving section having internal interdigitated electrode layers for causing piezoelectric vibration by a driving voltage applied to an input terminal;

a first independent driven section longitudinally adjacent to the driving section, comprising a plurality of piezoelectric ceramic layers polarized in the longitudinal direction of the piezoelectric plate, for generating a first output voltage at a first output terminal on a first major output surface by the piezoelectric vibration transmitted from the driving section;

a second independent driven section immediately above the driving section, comprising a plurality of piezoelectric ceramic layers polarized in the thickness direction of the piezoelectric plate, for generating a second output voltage at a second output terminal on a second major output surface by the piezoelectric vibration transmitted from the driving section;

a third independent driven section immediately below the driving section, comprising a plurality of piezoelectric ceramic layers polarized in the thickness direction of the piezoelectric plate, for generating a third output voltage at a third output terminal on a third major output surface by the piezoelectric vibration transmitted from the driving section;

the first output voltage and the second output voltage and the third output voltage are distinct defining a transformer with multiple driven sections providing multiple distinct output voltages.

12. The transformer of claim 11, wherein the first independent driven section further comprises a metallized strip substantially around outer surfaces of the first driven section and substantially in proximity to the driving section.

13. The transformer of claim 11, wherein overall power output is increased by electrically connecting at least the first output voltage and the second output voltage in parallel.

14. The transformer of claim 11, wherein overall voltage output is increased by electrically connecting at least the first output voltage and the second output voltage in series.