This is about on and off led system.
Here we can on and off the led by touching a particular part of circuit.
Step 1: Requirements for Making Circiut
Things needed are:
2. 555 Timer IC
3. Some wires
5.100 Ohm resistor
6.4 pins (As touch plates or anything which can conduct electricity)
7. 9 volt battery with battery clip
Step 2: Steps for Construction
1. Connect 555 Timer IC as shown in figure .
2. Now let's assume upper part of breadboard as positive part and negative part of breadboard as negative part.
3. Now connect a Wire from positive side of breadboard to the eigth (8th) pin of IC as shown in figure.
4.Connect another Wire from negative side of breadboard to the positive side of IC or first (1st) pin of IC as shown in figure.
5. Now connect another Wire from 8th pin of IC to 4th pin of IC as shown in figure.
6. Now connect anode of LED to the third pin of IC and cathode of LED to the blank space on breadboard as shown in figure.
7. Now connect 100 ohm resistor from first pin of IC to the cathode of LED as shown in figure.
8. Now connect touch plates or any other pins which can conduct electricity as shown in figure.
Connect touch plates from pin 1 and 2 of IC and pin 8 and 6 of IC as shown in figure .
9. Now connect 9 volt battery as shown in figure.
Connect positive end of battery to positive part of breadboard and negative end of battery to negative part of breadboard.
Now the circuit becomes as shown in figure.
So by performing all these steps properly the circuit works .
Led can be made on and off.