FERRO-ELECTRIC TRANSFORMERS WITH MEANS TO SUPRESS OR LIMIT RESONANT VIBRATIONS

• US 3,683,211 A
• Filed: 04/01/1971
• Issued: 08/08/1972
• Est. Priority Date: 04/05/1971
• Status: Expired due to Term

• Current Assignee: N/A
• Original Assignee: N/A
• Primary Examiner(s): J. D. Miller
• Assistant Examiner(s): Mark O. Budd
• Application Number:
  US05/131,341
• Time in Patent Office: 495 Days
• Field of Search: 310/8-8.7,9.1-9.4,9.8
• US Class Current: 310/326
• CPC Class Codes: H10N 30/40 with electrical input and electrical output, e.g. functioning as transformers

Abstract

Mechanically coupled ferroelectric capacitors are surface mounted on a rigid substrate so as to suppress resonant modes of vibration and to limit non-resonant modes of vibrations to those which result in the same polarity output signal. The mechanical vibrations caused in one capacitor (the input capacitor) by an input signal mechanically couples to the other capacitor (the output capacitor) and induces an output signal therein due to the piezoelectric properties of the dielectric. The structure is sandwich-like and consists of a first electrode, a ferroelectric body, a common electrode, a second ferroelectric body and a second electrode. The second electrode is preferably mounted on a rigid substrate.

Claims

1. An adaptive electronic transformer structure comprising an input capacitor and an output capacitor adjacent each other, said capacitors being mechanically coupled piezoelectric capacitors and separated from each other by a thin electrode, at least one of said capacitors possessing ferroelectric properties, and mounting means coupled therewith for supressing resonant mechanical vibrations of said input capacitor while leaving essentially non-resonant vibrations with net components of mechanical stress in one direction, thereby creating a polarity output signal in the output capacitor.

2. The transformer structure recited in claim 1 wherein said means for suppressing mechanical vibrations is substantially temperature insensitive over the operating temperature of said device.

3. The transformer structure recited in claim 2 wherein the piezoelectric material of said capacitors has an essentially flat temperature response.

4. An adaptive electronic transformer structure comprising a pair of mechanically coupled piezoelectric capacitors adjacent each other and separated by a thin electrode, at least one of said capacitors possessing ferroelectric properties, and a rigid substrate means upon which one of said capacitors is surface mounted by a layer of epoxy cement in order of 1 mil thick, said rigid substrate being selected from the group consisting of glass, quartz, ceramic and brass, and the thickness of said substrate means being such that flexure of said structure occurs about a plane which lies below the middle of the mounted capacitor, whereby the polarity of the net output signal due to flexure is the same as that due to radial stress components.

5. An adaptive electronic transformer structure comprising a transformer comprised of a pair of mechanically coupled piezoelectric capacitors, at least one of which is also ferroelectric, a rigid substrate upon which said transformer is surface mounted by means of a thin layer of a cement, said surface mounting suppressing resonant vibrational modes in said transformer and limiting non-resonant vibrations to essentially those which yield the same net polarity output signal, a thin flexible coating over the exposed surFaces of said transformer and a thick encapsulant over said flexible coating.