| 摘要 |
<p>An electric tubular heating element comprises a tubular metal casing provided with electric terminals at either one of both ends for a coil of resistance wire surrounded by an insulating material. The coil extends through the metal casing between the terminals. A temperature controller is, via an inner terminal (7), connected to a first of the terminals of the tubular heating element and has an outer terminal (8) thus forming a terminal of the tubular heating element. The temperature controller comprises an insulating sleeve (13), the inner terminal (7) being provided at the inner end of the sleeve and the outer terminal (8) being provided at the outer end of the sleeve; a bimetal switch (18, 21) which, when in closed position, interconnects the inner and the outer terminal; and a resistor element (19) connected in parallel with the bimetal switch and having such a resistance that the heat generated by the resistor element when the bimetal switch is open, is sufficient to maintain the switch in the open position.</p> |
