voltage 3A booster regulator

lektor july/august 1983 v 37 voltage booster regulator There are various ways and means of drawing more current from a voltage regulator IC than it was originally intended to supply, but most methods have their disadvan- tages. lf, for instance, a power transistor is connected in parallel with the IC, the supply wilt no longer be protected against short- circuits. That can, of course, be remedied by adding a current sensor in the shape of an extra transistor which, during overload conditions, cutsoffthebasecurrenttothe power transistor. But this solution suffers from a heavy power loss during short-circuit conditions, which is not really acceptable either. The circuit given here shows that a simpler solution is possible: the power transistor, Ti, is provided with an emitter resistor! This ef- qtr o aw R2 1n2 D242 4W ti tiL 3A g40C2200/ Ct 3200 C2 Tan a~..~ tu C B7 + 78XX xxv 2A Tan.t. Output Tr B1 cl R1 R1" R2 Ti Ti" Heat- C urrent current (T ype) in μF in in in (Type)(Type)sink ...