| 摘要 |
<p>A capacitive acceleration sensor using a common PWB as one of the plates of the capacitive transducer and the wiring connections thereto. An acceleration input moves a capacitor plate to produce a measurable change in capacitance. An electronic signal conditioner (14) accurately converts the capacitance output to a voltage signal to provide an acceleration sensor featuring accurate DC performance. The transducer and electronics are disposed on a PWB making up a complete sensor package. In a first embodiment, the capacitor comprises a fixed electrode (3) on the PWB (1) and a movable acceleration responsive electrode (9) secured to a support (7) by a conductive resilient member (8), the support (7) coupled to an electrically conductive region (2) on the PWB (1) spaced from the fixed electrode (3) by a guard ring (4) to minimize stray charge between the capacitor electrodes. In a second embodiment, the movable capacitor electrode (21) is supported at its center by a pair of electrically conductive members (22, 22'), one coupled to an electrically conductive region on a substrate (24) spaced from the movable electrode by a sealing spacer (25). The fixed capacitor electrode is disposed either on the same substrate or a separate substrate on the opposite side of the movable electrode spaced from the movable electrode by a sealing spacer and having the fixed capacitor electrode thereon. The movable capacitor electrode can be secured at its center or at an edge and can be produced by stamping and/or photoetching and provide a single element where plural elements were previously required.</p> |
