In Part-1 We have designed 5 volt smooth DC source for mobile charger . In this section we are going to make a short circuit protection circuit so that if any short circuit occurs the whole circuit will not be damaged . This circuit is enough to charge a battery . As shown in schematic diagram below if button is pressed the short circuit will occurs in this case the D5 LED will glow instead of damaging the whole circuit . The operation of this circuit is shown below
How short circuit protection activated ?
The transistor can be used in two application one is to amplify the signal and another is as a switch . In this example we have used transistor as a switch . First if we do not press button ie in the case of open circuit first Q2 and then Q1 get activated and the current starts flowing through D6 in that case D5 get reverse biased so main charging LED glows . And when we short circuited the The path always follows least resistance in that case both of the transistor goes off and D5 get forward biased . and we can obtain output from D6 .
That's all about the circuit . If you have any question about this circuit please leave a comment below . If you found this useful please share this .