Electronic control device for a piezo-ceramic bending transducer designed as a trimorph

• US 8,053,949 B2
• Filed: 08/11/2007
• Issued: 11/08/2011
• Est. Priority Date: 08/11/2007
• Status: Active Grant

• Current Assignee: Festo SE & Company KG
• Original Assignee: Festo AG & Company KG (Festo GmbH & Company KG)
• Inventors: Wirtl, Hannes
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): Gordon; Bryan P
• Application Number:
  US12/310,060
• Publication Number:
  US 20110163631A1
• Time in Patent Office: 1,550 Days
• Field of Search: 310/317, 310/318, 310/319, 310/332
• US Class Current: 310/317
• CPC Class Codes: H10N 30/204 using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
• CPC Class Codes: H10N 30/802 Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits

Abstract

An electronic control device for a piezo-ceramic bending transducer designed as a trimorph, wherein a first voltage divider consisting of two resistor branches and powered by a first voltage source (U_st1) is provided, whose first resistor branch connects the first piezo-ceramic plate of the trimorph to its spacer layer. In addition, a second voltage divider is provided that consists of two resistor branches and the first resistor branch thereof connects the second piezo-ceramic plate of the trimorph to its spacer layer. The second resistor branch of the first voltage divider also forms the second resistor branch of the second voltage divider. Thus, by means of one voltage source, the one piezo-ceramic plate has an applied tensile stress and the other piezo-ceramic plate has an applied compressive stress, so that the flexural motion is reinforced by the two piezo-ceramic plates and thus only a small voltage has to be applied.

Claims

1. An electronic control device for a piezo-ceramic bending transducer designed as a trimorph and comprising two piezo-ceramic plates with a passive spacer layer located therebetween, with a first voltage divider comprising two resistor branches and powered by a first voltage source, wherein the first resistor branch connects the first piezo-ceramic plate to the spacer layer, and wherein a second voltage divider comprising two resistor branches has a first resistor branch that connects the second piezo-ceramic plate to the spacer layer, wherein the second resistor branch of the first voltage divider also forms the second resistor branch of the second voltage divider.

2. An electronic control device according to claim 1, wherein the two first resistor branches each have a series circuit of a diode with a resistor element.

3. An electronic control device according to claim 1, wherein the first two resistor branches each have the series circuit of a diode with a Z-diode.

4. An electronic control device according to claim 3, wherein the diodes and the Z-diodes are each oppositely poled.

5. An electronic control device according to claim 2, wherein the cathodes of the two diodes of the two first resistor branches are connected together either directly or indirectly.

6. An electronic control device according to claim 1, wherein a resistor element is circuited between the first resistor branches and the piezo-ceramic plates.

7. An electronic control device according to claim 1, wherein the second voltage divider can be connected to a second voltage source, wherein the voltage sources can be switched on alternately.

8. An electronic control device according to claim 1, wherein the first voltage source can be applied to and switched between the first or the second voltage divider.

9. An electronic control device according to claim 1, wherein the trimorph is designed as a valve switching element of a valve.

10. An electronic control device according to claim 9, wherein the electronic components are arranged on or are integrated into a flex-conductor of the valve.

11. An electronic control device according to claim 3, wherein the cathodes of the two diodes of the two first resistor branches are connected together either directly or indirectly.

12. An electronic control device according to claim 4, wherein the cathodes of the two diodes of the two first resistor branches are connected together either directly or indirectly.

13. An electronic control device according to claim 2, wherein a resistor element is circuited between the first resistor branches and the piezo-ceramic plates.

14. An electronic control device according to claim 3, wherein a resistor element is circuited between the first resistor branches and the piezo-ceramic plates.

15. An electronic control device according to claim 4, wherein a resistor element is circuited between the first resistor branches and the piezo-ceramic plates.

16. An electronic control device according to claim 5, wherein a resistor element is circuited between the first resistor branches and the piezo-ceramic plates.

17. An electronic control device according to claim 2, wherein the second voltage divider can be connected to a second voltage source, wherein the voltage sources can be switched on alternately.

18. An electronic control device according to claim 3, wherein the second voltage divider can be connected to a second voltage source, wherein the voltage sources can be switched on alternately.

19. An electronic control device according to claim 4, wherein the second voltage divider can be connected to a second voltage source, wherein the voltage sources can be switched on alternately.

20. An electronic control device according to claim 5, wherein the second voltage divider can be connected to a second voltage source, wherein the voltage sources can be switched on alternately.