| 摘要 |
<p>Energising apparatus is used to energise a set of identification tags of an identification system. The tags then emit identification signals which can be detected and analysed to identify, for example, cattle moving into a milking parlour or feeding station. The energising apparatus has a number of antenna coils situated in range of a detection means, and current supply means (64, 60) for supplying current to said coils, to cause said fields to be generated. The pattern of current flowing through the coil is altered by means of current control means (62) so as to alter the direction of said fields in the detection zone. This change of direction enables a pick-up element therein to be energised in any one of a number of possible orientations.</p> |
