Method for (prepolarizing and centering) operating a piezoceramic power switching device

Abstract

This application describes a number of novel advanced piezoelectric ceramic power switching devices which are mounted within protective gastight enclosures that are either evacuated to a high degree of vacuum or filled with an inert gas protective atmosphere. The devices thus constructed are capable of operating over a range of load voltages extending from about 100 volts to 5000 volts or more with corresponding currents of from a few amperes to hundreds of amperes and wherein it is possible to provide a number of such structures in a single common protective gastight enclosure. For certain circuit applications the devices thus constructed have unpoled portions on which are mounted either passive circuit components such as resistors, capacitors and the like or active semiconductor devices all interconnected in circuit relationship with each other and the switching devices by using printed circuit or integrated circuit fabrication techniques. In these devices, stray circuit impedances whether capacitive, inductive or resistive in nature can be reduced to an absolute minimum by appropriate designs. Such complementary circuit components and active semiconductor devices can be, if desired, mounted within the common protective enclosures in close proximity to the piezoceramic switching devices to which they are connected, or alternatively may be mounted exteriorly of the protective enclosures.

What is claimed is: 
     
       1. The method of prepolarizing and centering the movable piezoceramic bender member of a piezoceramic bender-type switching device contained within a protective gastight enclosure which comprises substantially completing the fabrication assembly of all of the major components of the piezoceramic switching device into a unitary structure mounted within the protective gastight enclosure and sealed closed, applying a .[.relativey.]. .Iadd.relatively .Iaddend.high value prepolarization potential to the respective piezoceramic plate elements of the bender member while maintaining the plate elements near their Curie temperature to achieve dipole alignment of the dipoles of the piezoceramic material and simultaneously adjusting the relative magnitudes of the prepolarizing potential applied to the respective piezoceramic plate elements of the bender member to cause it to precisely position the movable switch contacts mounted thereon relative to fixed load current switch contacts of the switching device. .Iadd. 
     
     
       2.  A method of centering the movable piezoceramic bender member of a piezoelectric bender-type switching device contained within a protective gastight enclosure, the bender member having a pair of plate elements each having a planar outside surface, conductive surfaces on the planar surfaces, and a switch contact on the outside planar surface of each plate element adjacent a movable end of the bender member, the switching device having a fixed contact adjacent each of the movable contacts, comprising the steps of substantially completing the fabrication assembly of the major components of the switching device into a unitary structure mounted within the protective gastight enclosure, and   applying an initial potential to the conductive surfaces of the plate elements of the bender member and adjusting the relative magnitudes of the initial potential applied to the respective plate elements of the bender member to precisely position the bender member switch contacts between the fixed switch contacts. .Iaddend. .Iadd.   
     
     
       3.  The method of initially polarizing and centering the movable piezoceramic bender member of a piezoceramic bender-type switching device contained within a protective gastight enclosure which comprises substantially completing the fabrication assembly of the major components of the switching device into a unitary structure mounted within the protective gastight enclosure, applying a relatively high value initial polarizing potential to the respective piezoceramic plate elements of the bender member, and simultaneously adjusting the relative magnitudes of the initial polarization potential applied to the respective piezoceramic plate elements of the bender member to cause it to precisely position movable switch contacts mounted thereon relative to fixed load current switch contacts of the switching device. .Iaddend. .Iadd. 
     
     
       4.  The method of claim 2 wherein the fixed contacts and movable contacts enable make or break connection to at least two separate electrically conductive paths extending through the contacts. .Iaddend. .Iadd.5. The method of claim 2 wherein the plate elements include a poled and unpoled portion with the initial polarizing potential being selectively applied to the poled portion. .Iaddend. .Iadd.6. The method of claim 5 wherein the unpoled portion of the selected plate element remains electrically neutral and physically unstrained during switching device operation. .Iaddend. 
     
     
        .Iadd.7.  The method of claim 5 wherein electric circuit components in the form of passive circuit elements and/or active semiconductor devices are physically supported by the unpoled portion of the selected plate element and are electrically connected in circuit relationship with the switching device. .Iaddend. .Iadd.8. The method of claim 2 wherein there are a plurality of bender-type piezoelectric ceramic switching devices physically mounted within a single common gastight protective enclosure with each such device being operated for controlling the electric load current therethrough. .Iaddend. .Iadd.9. The method of claim 8 wherein each bender-type piezoelectric ceramic switching device within the common protective enclosure includes its own coacting first and second electric switch contact means and operates independently of the other switching devices mounted within the common protective enclosure. .Iaddend. .Iadd.10. The method of claim 8 wherein the bender-type piezoelectric ceramic switching devices mounted within the common protective enclosure are made to operate interdependently of the other switching devices mounted within the same common protective enclosure. .Iaddend. .Iadd.11. The method of claim 3 wherein the fixed contacts and movable contacts enable make or break connection to at least two separate electrically conductive paths extending through the contacts. .Iaddend. .Iadd.12. The method of claim 3 wherein the plate elements include a poled and unpoled portion with the initial polarizing potential being selectively applied to 
     
     
        the poled portion. .Iaddend. .Iadd.13.  The method of claim 12 wherein the unpoled portion of the selected plate element remains electrically neutral and physically unstrained during switching device operation. .Iaddend. .Iadd.14. The method of claim 12 wherein electric circuit components in the form of passive circuit elements and/or active semiconductor devices are physically supported by the unpoled portion of the selected plate element and are electrically connected in circuit relationship with the switching device. .Iaddend. .Iadd.15. The method of claim 3 wherein there are a plurality of bender-type piezoelectric ceramic switching devices physically mounted within a single common gastight protective enclosure with each such device being operated for controlling the electric load current therethrough. .Iaddend. .Iadd.16. The method of claim 15 wherein each bender-type piezoelectric ceramic switching device within the common protective enclosure includes its own coacting first and second electric switch contact means and operates independently of the other switching devices mounted within the common protective enclosure. .Iaddend. .Iadd.17. The method of claim 15 wherein the bender-type piezoelectric ceramic switching devices mounted within the common protective enclosure are made to operate interdependently of the other switching devices mounted within the same common protective enclosure. .Iaddend.