| 摘要 |
<p>The invention concerns a proximity switch supplying an electric signal which is a function of the presence of a reference element to be detected, in conformity with the NAMUR standard, comprising a sensor associated with an electronic processing circuit. The invention is characterised in that the sensor consists of an optical detector, such as an optical barrier, including a light source and a light-sensitive detector, and the electronic processing circuit includes a FLIP-FLOP circuit whereof the output controls a transistor such that the circuit equivalent resistance varies between a low value and a high value depending on whether the element to be detected is present or not.</p> |
