Posted in WorkshopEnergy


About: I am an electrical student living at chennai i love electronics very much.

Hai readers iam going to show how to make the pencil lead to glow like a light. During the process the lead can reach upto 300°¢ so be carefull while doing this.

Step 1: •°Components Required•°

* Pencil Lead
* Testube
* Meatel cap X 2
* Big Needle X 2
* ball point pen nib to hold lead at the edges
* 15 V DC supply

Step 2: °•Use 0.7 Lead•°

I used 0.7 pencli lead and 15V Dc power supply from li-ion battery

Step 3: °•Setting Up the Lead Inside the Tube°•

First take the Testube and break the bottom of the test tube. Now take metal cap and make hole in the centre of the cap. Now take the cloth stretching needle to make holder. To hold pencil lead you need to make holder. I used the ball point pen nib to hold the lead. Solder the ball point pen nib at the end of the needle by tieing it with thin copper wire. Now you can easily fix the lead inside the test tube

Step 4: •°POWERING UP°•

I powered this lead by using the 12v 7A li-ion battery the lead started glow by emiting the white coloured gas

Step 5: VIDEO



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    Awesome project buddy. loved it broda

    hey what do u meant from car battery ?

    Really Genius :)

    up to 20 - 25


    minutes or hours

    Why would'n I just use a bulb?

    What is the advantage of using a pencil instead of bulb?

    Is it juist the AC problem?

    1 reply

    i wanna 2 do something new...soo i choosed pencil lead...ya

    Won't this short circuit the battery and consequently cause it to over heat?

    4 replies

    Naw, if that were the case i think he would be nursing some severe acid burns.

    acid burns. at least i think that would be the case

    Well, just because there is something condictive between both terminals of the battery it doesn't mean it's a short circuit. In this case the "short" is actually the load: compared to the resistance of the wires and the internal resistance the resistance of the pencil lead is much higher (at least 10 times).

    Nice instructable btw. :)

    No short circuit the electric bulb is also using the same princple

    is there a chance the gas could be harmful or fairly to highly flammable? btw amazing project either way

    1 reply

    no the gas does't make any harm

    You can also use this in igination system

    :) thank you

    have you measured the current? how long before it burns out?