Today I am going to make a circuit of Light Sensitive Double LED Blinker.It means LEDs will blink alternate when no light will fall down on the LDR and LEDs will glow continuously when light will be on the LDR.
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Step 1: Take All Components As Shown Below
Step 2: Transistor - BC547
Pin-1 of this transistor is collector,
Pin-2 is Base and
Pin-3 is Emmiter of this transistor.
Step 3: Connect LED to Transistor
Solder -ve leg of LED to Collector pin of transistor.
Step 4: Connect LDR to Base of Transistor
Next solder one leg of LDR to Base pin of the Transistor as solder in the picture.
Step 5: Connect +ve Leg of LED
Next Connect +ve leg of LED to remaining leg of LDR as you can see in the picture.
Step 6: Make Like This of Another Transistor
Next we have to connect one more LED and LDR to another remaining transistor as shown in the picture.
Step 7: Connect Emmiter Pins of Both Transistors
Next solder emmiter pins of both transistors as solder in the picture.
Step 8: Connect Capacitor
Solder +ve pin of Electrolytic capacitor to Collector pin of 2nd transistor and
Solder -ve pin of capacitor to base pin of 1st transistor as you can see in the picture.
Step 9: Connect Again 220uf Capacitor
Solder +ve pin of this capacitor to Collector pin of 1st transistor and
-ve pin of capacitor to Base pin of 2nd transistor as solder in the picture.
Step 10: Connect +ve Leg of Both LEDs
Step 11: Connect 220 Ohm Resistor
Solder 220 ohm resistor to +ve leg of LED as solder in the picture.
Step 12: Connect Battery Clipper Wire
Now we have to solder battery clipper wire to the circuit.
Solder +ve wire of battery clipper to 220 ohm resistor and
-ve wire to emmiter pin of transistors as you can see in the picture.
Step 13: Connect Battery
Now connect battery to battery clipper and observe that -
1] When light will be on the LDR then Both LEDs will blink continuously as you can see in the picture-1 and picture-2.
2.] When light will not be on the LDR then LEDs will be linking alternately as you can see in the picture-3 and picture-4.