| 摘要 |
The heater (2) comprises a mirror surface in a support frame, and a resistance wire (7) connected to a voltage source. Behind the mirror surface is a support plate (6), the resistance wire being fixed against one surface of the support plate in a tension track (8). The track (8) is straight, and extends from one edge of the support plate (6a) to the other (6b). Parallel tracks are provided, and they can have a W-formation or one which is rhomboid. In the edges (6a,6b) of the support plate (6) are track end indentations (9) into which the resistance wire is hooked. The support plate (6) is of metal, and the tracks (8) are pressed around the resistance wire (7) at end apertures. (Provisional Basic advised week 83/41) |
