| 摘要 |
<p>A proximity switch, the sensing portion of which is an insulated electrode whose capacitance can be changed, for example by bringing one's finger close to the electrode, to operate the switch, wherein the charge in capacitance is coupled into a bridge circuit which has a delayed self-balancing action, so that rapid changes in capacitance will operate the switch but long term slow changes in the capacitance will fail to operate the switch.</p> |
