How to Make LED Flasher Circuit Using BD139 Transistor

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Components required -

(1.) Transistor - BD139 x1

(2.) Capacitor - 25V 2200uf x1

(3.) Capacitor - 50V 4.7uf x1

(4.) Resistor - 1K x1

(5.) LED - 3V x1

(6.) Power supply - 12V DC

This is the circuit diagram of this project.

Connect all components according to this circuit diagram.

Solder +ve pin of capacitor to Base pin of transistor

and solder -ve pin of capacitor to emmiter pin of the transistor as solder in the picture.

Next we have to solder +ve pin of 2200uf capacitor to emmiter pin of the transistor as you can see in the picture.

Next we have to solder +ve leg of LED to Collector pin of transistor and

solder -ve pin of LED to -ve of 2200uf capacitor as you can see in the picture.

Next solder 1K resistor to -ve pin of 2200uf capacitor/-ve leg of LED as solder in the picture.

Our circuit is completed.

So Now we have to connect input power supply wire to the circuit.

Connect +ve clip to Emmiter pin of Transistor and

Connect -ve clip to 1K resistor as you can see in the picture.

NOTE : We have to give 12V DC Input Power supply to this circuit.

Now LED will be flashing.

Thank you