| 摘要 |
Each heating line (10) has two heating conductors (11, 13), arranged at a distance from one another, between which there is arranged a further conductor (cold conductor 12) whose cross-section is dimensioned such that the temperature increase when current flows is negligible with respect to the temperature increase of the heating conductors (11, 13). The three conductors are located essentially in a plane and can thus be insulated individually (individual insulation 14), or can be housed in a common insulation. As a result of the design according to the invention, there is a possibility that the three conductors can be connected to one another in a suitable manner, as a result of which four resistance values can be achieved with one line, by means of different interconnections. <IMAGE> |
