| 摘要 |
<p>EP--98913 A (+22.3.82, 13.4.82, 23.8.82 (2), 14.10.82, 7.12.82, 15.12.82, 21.12.82 (3) 24.12.82 (2) -ES- 510664, 511397, 515186, 515187, 516506, 518012 518238, 518343 (5) (6), 518567, 518568) The device is disposed on or in an object to the protected and the conductive sphere is caused to be positioned in a given zone (D1) where it causes closure of either switch of a pair of switches but not both switches simultaneously. The interval between the intants of closure of the two switches represents the amplitude and rapidity of movement of the object. Slight displacements or vibrations will not cause both switches to close due to the distance separating them but sudden violent displacements caused by a bag being snatched will cause an alarm. - The switches may be constituted by interdigitated printed conductors on a circuit board, the spacing between the conductors being such as to allow them to be bridged by the conductive sphere. Various forms of electronic monitoring circuit are described to trigger an alarm device in response to the two switches being closed in response to violent movement of the conductive sphere, using bistable circuits. The path has zones of differing curvature to provide a variation of the movement sensitivity. (4/55)</p> |
