Fluorescent starter is essentially two bimetallic strips in a sealed glass capsule, with a small gap between them.

The principle of this experiment is Metal expansion and contraction .

1-  12 volt CPU Fan.
2-  12 Volt supply.
3-   Fluorescent starter.
4- Candle.

1- Break the starter glass and try to not damage the metal inside (Take all safety precaution when you do that to avoid any injury).
2- Make sure that there is a small gap between two metal as shown in attached picture. 
3- Connect the circuit as attached in the first circuit diagram and fix the starter about 2 cm above the candle.

When the candle lighted up ,the starter metal  will expand and attached together , the fan will turn on  and turn off the candle ,the two metal will de-attach and turn off the fan.

Note that CPU fan is a brush less dc motor and it will not cause spark in starting ,the spark can damage the metal and it will not work for long time ,so if you connect a load that take more current  and cause a spark in the starter you can use transistor showed in the last diagram to avoid this issue .

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Many thanks


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it is very good and i made it for my school exhibition i got first thank you very much for this project
You're most welcome.
should try it with a smaller fan? and or angle the fan so it doesnt blow the candle out?
your rock Husham Samir!!!
Love it! You made a &quot;most useless machine in the world&quot; (see vid and somewhere on this site...) while demonstrating a clever thermo-switch. Thumbs up!<br> <br> <div class="media_embed"> <iframe frameborder="0" height="360" src="http://www.youtube.com/embed/Z86V_ICUCD4?rel=0" width="480"></iframe></div>
Nice video ,I love it ,thank you for sharing.
very nice .................................but why did you use TRANSISTOR in this project ............? <br>
Thank you Divya <br>if I am not using the transistor ,the circuit will work but a spark will happened every time the metal attached and it will damage the bimetallic strips ,so the purpose from the transistor to increase the life time of bimetallic strips. <br> <br>Regards <br>Husham
Good project, excellent thinking out of the box ! !<br /> <br /> A
Thank you.
Nice info. i think by modding the gap between the terminals, once can make a parked car cooler using a similar circuit. it will automatically start the fan and rotate the air inside the car when the temperature rises and shut off when cooled. <br /> <br />can you do a test and measure the temperature when it starts bending? so we can accordingly know when it switches at what temperatures.. <br /> <br />Thanks
Thank you francisdsa <br />I have tried your suggestion but unfortunately it is not efficient because the two metal is too small and not easy to twist them to get the required setting . <br />for a project like parked car cooler I suggest you to use LM35 temperature sensor with op-amp comparator . <br /> <br />
Very interesting, thanks for sharing.

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Bio: Electrical Engineer
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