CIRCUIT PROTECTION DEVICE

摘要

2096641 9210878 PCTABS00014 A circuit protection arrangement that is intended to be series connected in a line of an electrical circuit comprises a transistor switch (1) that controls the circuit current and has a control input, and a control arrangement that controls the voltage of the control input of the switch. The control arrangement comprises a comparator circuit (3) that compares a fraction of the voltage across the switch (1) with a reference voltage, for example supplied by a Zener diode or bandgap diode, and opens the switch if the fraction is greater than the reference voltage. The comparator circuit is powered by the voltage drop in the line across the switch so that the arrangement can be formed as a two-terminal device that requires no external power source. The arrangement has the advantage that it exhibits a relatively small variation in performance with respect to temperature variations.