Protection cct. for regulated power supplies - has thyristor bridging supply and diode across regulating transistor

摘要

The protection circuit, for regulated power supplies, has a thyristor in series with a diode across the input side of the supply lines after the thermal fuse but before the regulating transistor coupled into the negative line. The thyristor gate is connected to the output of a comparator whose two inputs are connected one to each supply line. A diode is connected across the regulating transistor and the first diode so that its anode is coupled to the thyristor cathode - i.e. the two are in the same conduction direction. The thyristor is bridged by a resistor. The first diode cathode is connected to the negative supply pole, and its anode to the thyristor cathode.