| 摘要 |
PURPOSE:To secure the separating operation of a movable electrode from a fixed electrode with the static electric force even under the condition that the movable electrode as a detecting element is made to contact or come close to the fixed electrode by the gravity at the time of turning on a power source of a static servo type capacitive acceleration sensor. CONSTITUTION:A movable electrode 5 is displaced in response to the acceleration, and is static-servo-controlled so as to be positioned in the middle of fixed electrodes 2, 3. Displacement, and furthermore, acceleration of the movable electrode 5 is detected on the basis of a difference of the static capacity between the fixed electrodes 2, 3. At the time of turning on a power source, in the case that the movable electrode 5 is made to contact or come close to the fixed electrode 3 by the gravity, a cycle period of the voltage to be applied to the electrode is prolonged than the usually, and the duty of the fixed electrode 3 of the contact side is made smaller, and the duty of the other fixed electrode 2 is made larger. As a substitute for the described way, an electrode voltage wave height value is changed to the usually value or a projection, an insulating material and a recessed part or the like is provided in the electrodes to arrive the described aim. |
