Heating device for the electrical planar heating of the rear surface of exterior mirrors

摘要

The invention relates to a heating device for the electrical, planar heating of the rear surface of, in particular, motor vehicle exterior mirrors. In accordance with the prior art, motor vehicle mirrors are heated in two stages, specifically in separate surface sections. This has the disadvantage that the non-heated surface section can mist up. There is provision for two heating circuits (2/3), of differing power, which are guided inside one another with constant spacing to be arranged on the surface (1) to be heated, the lower power heating circuit being constructed as a permanent heating circuit (3) and the higher power heating circuit being constructed as a switching heating circuit (2) controlled by a thermoswitch (4). The thermoswitch (4) takes up the temperature from both heating circuits (2/3). This construction ensures that in each case the complete surface is heated, specifically irrespective of whether only the permanent heating circuit (3) or at the same time the switching heating circuit (2) is switched on. IMAGE