| 摘要 |
1,234,218. Transducers. INDUSTRIAL RESEARCH PRODUCTS Inc. 28 Nov., 1968 [29 July, 1968], No. 56419/68. Heading H4J. The diaphragm of a piezo-electric transducer has one edge hingedly connected to a support so that the diaphragm functions as a hinged flap, and one end of the piezo-electric element is fixed to the support. A miniature microphone unit for a hearing aid has a piston-like rigid diaphragm 28, (Figs. 1, 2) hingedly mounted at one edge at a rigid metal strip 32 or at a large mass of adhesive (not shown). The remainder of the diaphragm edge is supported by flexible surround 30. The diaphragm assembly 16 and a converter assembly 18 including a piezo-electric element 38 are mounted on opposite sides of a carrier 12 and all are contained in a metallic housing 20 having a metallic cover 22 to provide electrostatic shielding. The cover 22 has an aperture 24 and baffle plate 26. The diaphragm 28 has stiffening rods 34 and a depression 37. The piezo-electric element 38 is fixed to the carrier 12 by a conductive clip 40 touching one conductive face of element 38. A pin 42 connects the element 38 and diaphragm 28. A F.E.T. 44 (Fig. 5) is mounted on one side of the carrier 12 (Fig. 4, not shown) and a circuit is formed by printed circuit pads (52, 56) and bias and load elements 46, 48. A battery is connected across leads 56, 58 and a further amplification stage or an earphone is connected across leads 68 or 58 and 70. Components such as transistor 44 and element 46 are encapsulated in plastics material 74 together with the clip 40. |
