Short-circuit-resistant temperature-dependent switch

摘要

The invention relates to a circuit principle which allows thermal switches which contain a resistance bridge circuit, a comparator circuit connected thereto and a power stage operated by the comparator circuit, to be constructed in a short-circuit-resistant manner. The circuit principle is essentially based on the fact that the voltage drop across a current sensor resistor connected in series with the load to be driven is used in the short-circuit case for applying, for a time determined by an RC section, a potential via a transistor stage to one of the inputs of the comparator circuit which leads to a switching state at the output of the comparator circuit which disconnects the power stage.