| 摘要 |
<p>The air sounder appts. (1) consists of a metal ring (2), a metal membrane (4) and a piezo-ceramic foil (6), which has an electrode coating (7) on its outer surface. The counter electrode (7) is fixed on the ceramic foil (6) in the same way as the electrode coating (7), and is connected with the metal membrane (4) so that it is conducting. The metal membrane (4) is fixed at the ring (2) by its edge, which extends over the upper edge of the ring to the outer surface, where it is soldered or held by a second ring (2'). The metal membrane takes up a flat position (4') on assembly, and in order to mould it to its fixed form (4), a press tool (9) is inserted into the ring (2), from below. This leaves the membrane (4) fully shaped after which the tool (9) is withdrawn. The sounder can be made small with a high sound output in the region of 1 to 2 khz.</p> |
