| 摘要 |
<p>The device has resistance foils that are pressed-in between plates made of steel, aluminum or plastic. The plates are filled with a plastic material and have a wavelike or trapezoidal design for surface area enlargement. The plates have thickness ranging from 0.7 to 1.5 mm and are screwed, welded or adhered with each other. The plates have cooling ribs, and a dimmer circuit is provided for temperature control. A temperature monitor monitors temperature of the plates in a preset temperature range based on bimetallic switches.</p> |
