| 摘要 |
<p>This invention relates to an electronic detector which in combination with other sensing means e.g. for weight, dimension and deformation force, provides a reliable safety that a refund is only paid for approved aluminium cans and that the collected and compressed aluminium scrap is not contaminated by another material. The electronic sensing is baaed on an electrically self-oscillating circuit containing a coil (3) placed around or at least partly enclosing the object (2) placed in the deposit apparatus. As the object (2) to be detected damps the above-mentioned oscillations it is possible by means of a suitable tuning of the electronic system to determine which frequencies belong to accepted aluminium cans. Thus, certain ranges of frequency correspond to accepted cans while ranges lying outside are considered as not accepted. By means of a microprocessor these approved or not approved ranges can be easily sorted out. The above-mentioned electronics adapted to this sorting system in return apparatuses for aluminium cans give a reliable safety as far as sorting out faulty or not accepted material is concerned.</p> |
