| 摘要 |
A temperature switching device for an electrotechnical part to be protected against an excess temperature due to a fault, with a first bimetallic switch and an ohmic resistor connected in parallel thereto, so that, after opening the bimetallic switch as a result of an excess temperature, the flow of current takes place across the ohmic resistor, which produces heat and as a result the bimetallic switch is kept open even in the case of the cooling of the excess temperature initially triggering the switching process due to a malfunction of the electrotechnical part to be protected, as a result of the evolution of heat of the ohmic resistor. At least the ohmic resistor is connected in series with a further automatically resettable thermal switch having an opening temperature above that of the first thermal switch, but well below temperatures causing irreversible damage to bimetallic elements and the two thermal switches being in close thermal contact.
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