Protection circuit e.g. for polarity reversal in motor vehicle low voltage applications

摘要

A protection circuit for a load (2) connected to a supply voltage source and having a field effect transistor (1) whose gate terminal is connected to a control circuit (4) connected to the supply voltage source. The FET-source terminal is connected to one terminal (V) of the supply voltage source and its drain terminal is coupled to one terminal of the load (L), in which the other terminals of the load and supply voltage source are interconnected. The conductivity type of the FET (1) as well as its control (drive) is arranged such that the FET (1) with correct polarity of the supply voltage source for the load is driven inversely and is switched on, while with the polarity of the supply voltage source incorrect for the load (L), the FET is operated normally and is switched off.