firstly i want to thank 1up for his amazing instructable on making joule thief.today i want to share making of joule thief. white or blue led lights at almost 3 volts.but by using joule thief you can run leds at even 0.5 volts.but in this instructables i will be using 1.5 volt battery.you can use the last bit of energy in the battery using this circuit.i am not good in electronics but even i could do it because it is easy.using this you can reuse dead batteries and help in greening of earth so lets start..its easy and great for scientific classes and experiments.
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to see some more of this type of interesting projects
Step 1: Things you will need
this is a cheap project .things needed are also common and cheap.this are the things that you will need:
1)some thin wire.
2)a white or blue led.
3)a 1000 ohm resistor.i got mine from a toy.so leads are small.
4)any npn trnsistor-1.(but transistors like 2n3904 or 2n4401 or bc337 etc are good choice)but if you use pnp transistor you will have to reverse the polarities.
5)a ferro magnetic core like toroids.if you dont have toroids then take the circuit of a decreased fluorecsent bulbs .there you will see one type of round nut wrapped in wire.there you have your toroid.
6)an aa battery
tools you will need:
soldering iron or pliers
beside the things picture you may see white dots.those are reflections of flashlights.
take wires of two colours and of same size.different colours does not matter. it is only for recog nizing the wires correctly.
Step 3: Wrapping the toroid
take the wires together and start wrapping the toroid.after wrapping you will find four ends.two of blue wire and two of red wire.now twist and connect one end of blue wire to one end of red wire.