Efficiency driver system for piezoelectrics

• US 5,245,242 A
• Filed: 04/13/1992
• Issued: 09/14/1993
• Est. Priority Date: 04/13/1992
• Status: Expired due to Fees

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Hall, James R.
• Primary Examiner(s): Budd, Mark O.
• Application Number:
  US07/867,559
• Time in Patent Office: 519 Days
• Field of Search: 310/316, 310/317, 310/319, 318/116
• US Class Current: 310/316.03
• CPC Class Codes: H10N 30/802 Drive or control circuitry or methods for piezoelectric or electrostrictive devices not otherwise provided for

Abstract

This invention drives a piezoelectric element by transferring energy from one element 5 to another 6 by way of an intermediate inductor 4. Additional energy is obtained from an energy source 1 to make up for internal losses and for the work performed by the piezoelectric elements. The energy is transferred as needed by switches which are operated by a controller for proper timing of energy transfer between the elements and energy boosts from the energy source.

Claims

1. A driver system for transferring charge between piezoelectric elements comprising,

a first piezoelectric element,

a second piezoelectric element,

an inductor connected between the first and second piezoelectric elements,

a connection between the first and second piezoelectric elements to complete a circuit

a switch for opening and closing the circuit

a means for controlling the switch position.

2. A driver system for transferring charge between piezoelectric elements as in claim 1 wherein the inductor is a saturable inductor for transferring non linear wave forms.

3. A driver system for transferring charge between piezoelectric elements as in claim 1 wherein there is a means of adding energy to the system from an energy source.

4. A driver system for transferring charge between piezoelectric elements as in claim 2 wherein there is a means of adding energy to the system from an energy source.

5. A driver system for transferring charge between piezoelectric elements comprising,

a first piezoelectric element,

a second piezoelectric element,

a first switch and a second switch,

an inductor connected between the first and second piezoelectric elements, wherein the first switch is between the first piezoelectric element and the inductor and the second switch is between the inductor and the second piezoelectric element,

an energy source,

wherein the energy source, the first piezoelectric element and the second piezoelectric element have a common ground connection,

wherein the switches can select if the inductor is connected to the energy source the piezoelectric actuator, or the common ground connection,

a means for controlling the switch positions of the switches for transferring energy between the piezoelectric elements and adding energy from the energy source.

6. A driver system for transferring charge between piezoelectric elements as in claim 5 wherein the inductor is a saturable inductor for transferring non linear wave forms.

7. A driver system for transferring charge between piezoelectric elements comprising,

a first piezoelectric element,

a second piezoelectric element,

an inductor,

an energy source, and

a switch,

wherein the first and second piezoelectric elements, the inductor and the energy source all have a common ground connection and wherein the switch alternately connects the inductor to the first piezoelectric element the second piezoelectric element or the energy source,

a means for controlling the switch position of the switch for transferring energy between the piezoelectric elements and adding energy from the energy source.

8. A driver system for transferring charge between piezoelectric elements as in claim 7 wherein the inductor is a saturable inductor for transferring non linear wave forms.