GB1470111A - Transducer arrangements - Google Patents

Abstract

1470111 Piezoelectric generators SIEMENS AG 22 March 1974 [22 March 1973 5 Feb 1974] 8254/74 Heading H2A In a transducer arrangement, a parallelepipedic ceramic body 1 which is piezoelectrically active at least over a portion h of its overall length H has width and thickness dimensions l, d chosen such that h#3d, and l#3d, and a synthetic resin support body is provided to increase the resistance of the body 1 to bending in the thickness direction when force is applied to a keying surface. In the arrangement shown, the body 1 has electrodes 25 (24, Fig. 2, not shown) on the active portion h, and electrodes 125, (124) on a piezoelectrically inactive portion H-h, and is fastened to two support bodies 64, 164, e.g. of polyacrylic glass, vinyl ester/vinyl chloride copolymer, polystyrene or polyacrylic nitrile, the assembly being mounted in a keying body 90 to allow pressure to be applied in the direction 2. In the arrangement of Fig. 4 (not shown), a transducer (1) is mounted in a support body (70) of cruciform shape, and in the arrangements of Figs. 6-8 (not shown) the piezoelectrically active portions are divided into two separate regions with oppositely directed polarizations, the electrodes being connected so that generated voltages are summed. In the arrangement of Figs. 9, 10 (not shown), a transducer (201/1) is connected into a transistor circuit to switch current in a load (231) when the transducer is activated, an inactive section of the transducer body providing capacitance C and a resistive electrode providing resistance R in an RC filter. In the arrangement of Figs. 11, 12 (not shown) a resistive layer (8211) is applied between two electrodes (8125, 825) on a body 1, and connection (8224, 8225) are applied to two support bodies (864, 8164). In all cases the ceramic body may be lead titanate-zirconate or barium titanate, and the support body may be sprayed into position.