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THE BELL SYSTEM TECHNICAL JOURNAL, MAY 1952 



2.8 

 2.6 

 2.4 

 2.2 

 2.0 

 1.8 

 1.6 

 1.4 

 1.2 

 1.0 

 0.8 

 0.6 

 0.4 



I 2 3 4 5 6 7 8 9 10 11 12 13 



DEPOLING FIELD IN KILOVOLTS PER CENTIMETER 



Fig. 4 — Effect of 4 per cent lead titanate on the open circuit voltages generated 

 for 500 grams force, and for depoling voltages. 



vibrations of the relay structure. Fig. 6(b) shows the forces produced 

 by opening the contacts. The large spikes are due to wire vibrations. By 

 using such ceramics in various parts of the relay the points of high stress 

 can be located. 



The second type of structure which responds to tangential forces is 

 poled as shown by Fig. 5 so that the poling direction lies along the direc- 

 tion for which the tangential force is applied and perpendicular to the 



DIRECTION OF 

 POLING AND FORCE 



NORMAL TANGENTIAL 



Fig. 5 — ^Methods for polarizing barium titanate to respond to normal and tan- 

 gential forces. 



