| 摘要 |
<p>The force required to close the switch is pre-set by adjustment of the spring tension. In a preferred embodiment a pivoted arm (9) is operated mechanically (15, 16, 17) by the external force. One end of the pivoted arm closes electrical contacts against the spring. The external force can be that of an object whose weight is variable, or a gas (e.g., air) or liquid (e.g. water) whose rate of flow is variable; examples are an ambient temperature water evaporation device for controlling agricultural irrigation, a wind sensitive device giving driver warning of vehicle speed.</p> |
