Today I am going to make a circuit of traffic light.This circuit I will make using BC547 Transistors.
Let's get started,
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Step 1: Take All Components As Shown Below
Step 2: Fold Pins of Transistors Like This
As pins are folded in the picture like that we have to fold.
Step 3: Connect Red LED to Transistor
Solder +ve legs of Both Red LED to Collector pin of a Transistor.
Step 4: Connect Green LED to Transistor
Solder +ve legs of Both Green LEDs to Collector pin of 2nd Transistor.
Step 5: Connect Yellow LED to Transistor
Solder +ve legs of Both Yellow LED to Collector pin of 3rd Transistor as solder in the picture.
Step 6: Connect Emmiter of Transistors
Next we have to connect emmiter pins of all transistors and -ve legs of all LEDs (Red, Green and Yellow) to each other as you can see in the picture.
Step 7: Connect 1K Resistors
Next Connect 1K resistors to the Collector pins of all transistors as solder in the picture.
Step 8: Connect 100K Resistors
Next solder 100K resistors to the Base pin of Green and Red LED Transistor as you can see in the picture.
Step 9: Connect 33K Resistor
Solder 33K resistor to the Base pin of Yellow LED Transistor as solder in picture.
Step 10: Connect Out Wires of All Resistors
Next we have to solder Out wires of all Resistors as you can see in the picture.
Step 11: Connect 100uf Capacitor
Next solder +ve pin of 100uf capacitor to Base pin of Yellow LED Transistor and Solder -ve pin to Collector pin of Red LED Transistor as you can see in the picture.
Step 12: Connect 470uf Capacitors
[Capacitor 1] - Next connect +ve pin of 470uf capacitor to Base pin of Green LED and solder -ve pin to Collector pin of Yellow LED as solder in the picture.
[Capacitor 2] - Solder -ve pin of 2nd 470uf capacitor to Collector pin of Green LED Transistor.
Step 13: Connect +ve Pin of 2nd 470uf Capacitor
Solder +ve pin of 2nd 470uf Capacitor to Base Pin of Red LED Transistor using a wire as you can see in the picture.
Step 14: Connect Battery Clipper Wire
Solder +ve wire of battery clipper to Out wires of all resistors and -ve wire to common emmiter pins of transistors and -ve legs of LEDs as connected in the picture.
Step 15: Connect Battery
Now circuit is completed so connect Battery to battery clipper and see the Traffic Light how it is glowing.
NOTE : We can Increase/Decrease the timing of Red,Green and Yellow wire glowing by changing the values of capacitors.
Glowing of Traffic light I tried to show in the above pictures.