| 摘要 |
<p>Proximity sensors e.g. for use on lift doors. The systems shown has a number of improved features including bootstrapping the receptor antennae to avoid capacitance problems, arranging an antenna as pairs of antenna strips with circuitry to enable the location of a signal source relative to the antenna to be determined such that the antenna has asymmetric sensitivity, and circuitry to detect the presence of undersized potential trigger signals from door wobble, etc. and hence reduce the sensitivity to avoid such false triggers.</p> |
