| 摘要 |
PURPOSE:To enable alarming and detection of water pressure with a small size and a light weight by having one piezo-electric element acting as water pressure detection element and signaling element with switching thereof. CONSTITUTION:A piezo-electric element 9, a transparent plate-shaped body, makes up a dial glass. A pair of transparent electrodes 14 and 15 are applied opposite to each other on the top and the undersurface of the element 9. The element 9 is fitted into a front opening 19 of a case 18 through a packing 20 to protect a display 12. The transparent electrodes 14 and 15 are electrically connected to a circuit board 24 carrying LSI components 23 at both ends of the undersurface of the element 9 through coil springs 21 and 22. When a distorted voltage is generated with a water pressure applied on the piezo-electric element 9, it is sent to a voltage detection circuit to be converted into-water depth information. With the switching over to a time indication mode, the piezo-electric element 9 functions as a buzzer. |
