| 摘要 |
The invention relates to a plate-shaped, preferably flexible electric heating device whose heat-generating elements (1, 2) consist of plate or film material which has per se a suitable electrical resistivity, or which is provided with a pattern of resistance wires or resistance strips and with contacts (1A-B, 2A-B) for the current supply. Two heat-generating plate or film elements (1, 2) are folded together to form a twin element where the two individual elements are mutually oriented and connected in such a manner that the current direction (3) therein is made to be opposite at least over substantial regions of their planar extent. As a result, a reduction or complete elimination of magnetic fields around the heating device is achieved to a considerable degree. The primary application is as a bed heater, heated carpet and the like, which when used can remain close to the human body over a relatively long period of time. <IMAGE> |
