Introduction: Lead Light (Not a LED)

Picture of Lead Light (Not a LED)

This Instructable is about how to make a lead light that can also be used as an ignition system.

Disclaimer: this is a dangerous project.
1.This is very HOT up to 300 degrees minimum so be careful.
If you get hurt during this project it is not my fault.

Step 1: Materials

Picture of Materials

Battery (at least half an amp other wise it wont work)
Refills for refillable pencil also known as carbon graphite

Step 2: Put It Together

Picture of Put It Together

Step 1: Make sure your switch is turned off.
Step 2: Put the refill lead between the positive and negative wire and secure it inplace.
Step 3: Keep your hands away from the lead and turn the switch on.
Step 4: there should be smoke for a second (don't breath this in!) and then the lead should turn red.

Each refill should last at least 1 min.

Thanks and goodbye


cinthia_123 (author)2017-01-30

can anyone give me a link of where I can buy the switch and adapter cable!!

Yonatan24 (author)2016-01-01

You're using GRAPHITE! That is not Lead!

JamesA107 (author)Yonatan242016-06-07

maybe he is form NZ

Wyle_E (author)2008-12-11

You might get the carbon to last longer if you enclosed it in a jar with an inert atmosphere. Helium would probably be best, but nitrogen or even carbon dioxide would probably work. The temperature rise would expand the gas, so you would need a one-way valve to relieve the overpressure. Something as simple as a loose rubber stopper would be enough.

ReCreate (author)Wyle_E2008-12-13

Hey ive got carbon dioxide it comes out of my nose(right?)

andros1200 (author)ReCreate2008-12-22

Or your mouth.

kimvellore (author)andros12002014-09-24

You guys should not try CPR.

Haq3r00 (author)Wyle_E2008-12-19

It would be far more fun to put one of these graphite rods and 2 wires into a very small bottle of compressed butane, with a remote switch of course... It would have the same effect, the temperature would expand the gas, but no valves needed, the container itself would release the pressure Somehow though I don't think the graphite would burn for so long.

oni (author)Wyle_E2008-12-11

Thats a good idea ill have to try it one day.

oni (author)oni2008-12-13

I just tried it it except without the valve and all the gases started coming out of the lid.

Haq3r00 (author)oni2008-12-19


Haq3r00 (author)Wyle_E2008-12-19

Main issue would be when the Graphite cools down again... the jar would break from the vacuum.?....

osgeld (author)Wyle_E2008-12-11

even if you put it in a vacuum the light would burn much brighter and for quite a long time, its almost as decent as a modern light bulb

check out this link

junits15 (author)2008-12-14

this is very cool execpt, for the fact that the lead burns away, i wonder how this would look in a complete vacume.

Blaze_001 (author)junits152014-03-21

there is no such thing as complete vacume

junits15 (author)Blaze_0012014-03-23

it exists theoretically

Haq3r00 (author)junits152008-12-19

it would look like this.... First Few Seconds ______________________________ | _________Light___________ | |______________________________| After First Few seconds: Blindness: due to the explosion of rapid heat expansion and CO2 produced by burning Graphite, resulting in plastic/glass shrapnel to blind you.

junits15 (author)Haq3r002008-12-19

actully it cant burn in a vacume so I'm pretty sure it would not explode.:)

Nexnaught (author)2009-04-06

Is there a fancy name for the switch/adapter cable? Also, where can I get the materials?

Blaze_001 (author)Nexnaught2014-03-21

Materials: anywhere (Radio Shack, Home Depot etc.) i got the batt. from a broken rc, but u can get those from radio shack. it might be a bit expensive though.

hsarode1 (author)2011-09-19

To make it last for more than 1 min. what u have to do is. take a glass jar make two holes for the wire to pass in and then insert the wire and touch the lead ends then open the cap and put a tealight and close the jar after sometym the candle will go out of oxygen, so no oxygen the filament won't burn up soo fast.

imakethings (author)2009-02-03

cant it work with a 9v battery? does it needs to be 9.6?

oni (author)imakethings2009-02-06

It dosnt matter as long as it has high amps so no a 9v wont work

bigredlevy (author)oni2009-03-01

a couple of rechargeable 9V batteries wired in parallel would probably have a high enough current output though right?

oni (author)bigredlevy2009-03-07

That should work and probably be brighter than mine!

klingonprins (author)oni2009-06-05

it splodes with 2 much current, so be careful

junits15 (author)imakethings2009-04-10

put like 6 or seven D batteries in parallel

Killa-X (author)2009-02-28

I tryed this with 0.5 pecil lead, and 12V 2A. It got SO BRIGHT that it was like a lightbulb. It actually was like looking at a mini sun it was so intense.. It lasts only 5-8 seconds, but it glows my room up good. This is when i touch the connection to it very slightly... doesnt last long but its BRIGHT

junits15 (author)Killa-X2009-04-10

just like an ark lamp

twocvbloke (author)Killa-X2009-03-20

This is how they came up with the light bulb (it wasn't just Edison doing experiments like this), encasing the carbon (pencil lead) in a glass jar under vacuum would make it last longer and probably burn brighter... :)

DonQuijote (author)2008-12-11

how many amps does this stuff draw?

geeklord (author)DonQuijote2008-12-11

find the resistance of the graphite(not lead, by the way) and then theres a formula for it.....wikipedia maybe?

the_mad_man (author)geeklord2008-12-11

ohm's law. i forget how it goes but the one you want is:
voltage X resistance(in ohms)= amps

geeklord (author)the_mad_man2008-12-12

I was thinking the formula for the power consumption of a resistor. But ohms law is E=IR i knew that. E being voltage, I being amperage, and R being resistance.

geeklord (author)geeklord2008-12-12

power consumption in watts.....

verence (author)geeklord2008-12-12

Errrr, well.....

Ohm's law is U = I*R with U = Voltage, I = Current and R = Resistance.
Or, if you divide both sides by R and flip the around: I = U / R

Since the power for DC is P = U*I, you will find that P = U*U/R = U²/R
(double voltage gives four times the power!)

Since graphite has a pretty low resistance the current could be really high. For a valid calculation you would have the source resistance of the power supply (the battery here) into account.

So the resulting current will be:
I = U / (Rgraphite + Rbattery)

The inner resistance of NiCd or NiMH batteries (better accumulators) is very low. Bigger packs can drive ten or more Amps easily. Togehter with the low resistance of the graphite this results in the nice light show. (And is the reason why some of the laptop batteries exploded in the last years). So don't try that with alkaline or zinc-coal batteries - it's just a waste of money. The inner resistance of those is too high and will limit the current and the fun.

Boy, these accumulators would have made some of my first experiments in electronics so much more fun... ;-)

geeklord (author)verence2008-12-30

I think the formula for the power consumption(in watts) of a resistor is P=I2R, P being watts.

verence (author)geeklord2008-12-30

Yep, you are right. As P = U * I and U = I * R you might substitute U and get P = I² * R (always R in Ohm, I in Ampere and U in Volt).

But, with a 'normal' power source (that is a voltage source) you have a constant voltage (U) and you current will follow according to I = U / R. Normal batteries, accumulators or (especially) regulated power supplies act as constant voltage sources. That is within reasonable limits, things change when the source is shorted or heavily drained (like here). That's when the inner resistance and other effects (chemical etc.) come into play and make the voltage not be a constant factor any more.

If, on the other hand, you have a constant current source (not easy to be found, but can be done easily with an electronic circuit) the resulting voltage on a resistor will follow U = I * R and you will get the power with the formula you gave.

It just depends on the type of your source. Constant voltage vs. constant current. For easy designing, accumulators are treated as constant voltage type (until near empty). In real life... well, life is complicated, isn't it?

geeklord (author)verence2008-12-31


ranm (author)verence2008-12-12

Remember, the restistance can be OHMIC or non-ohmic, meaning that the resistance changes as the temperature of the graphite increases/decreases.

DonQuijote (author)ranm2008-12-12

graphite's resistance gets lower with the increasing temperature, at least up to a point, so i am pretty sure this thing needs a huge amount of current, but i was wondering if anybody ever bothered to MEASURE the ACTUAL EXPERIMENTAL current.

DonQuijote (author)DonQuijote2008-12-14

ok, i measured it meself and i got a reading of about 4 amps, but with the multimeter in between it did not got as bright as without, despite the fact that i used the un-limited current pins on the multimeter. you know, the ones that blow up your meter if there's more than 20 amps on it. either way, i figure it has some sort of inner resistance, so without it , it probably draws a bit more....... 4 amps, times the 5 v tension i put on it, that is about 20 watts of power draw......

Haq3r00 (author)DonQuijote2008-12-19

Its graphite... Can draw any amount of amps you like... Can also draw: Houses, Cars, And Fruit.

geeklord (author)2008-12-30

HAH! I've got a 3300 mAh NiMh RC car battery! lol

MrCakes14 (author)2008-12-08

This is pretty excellent :) How long does it last? Wouldn't the lead (graphite...filament...whatever you want to call it) burn out pretty quickly?

oni (author)MrCakes142008-12-09

Each refill is about half a millimeter thick and 6cm long and lasts 1 minute.

andros1200 (author)oni2008-12-22

There are different sizes such as .5mm .7mm and .9mm.

ReCreate (author)oni2008-12-13

in what gas? air?(i think oxygen and nitrogen and carbon dioxide)

Xellers (author)2008-12-18

This sin't too good of an idea for DIY lighting. What I did was take old bottles, clean them out, and then soldier in two electrodes. After that , you can string a hand wound filament from a strand of stranded wire between the electrodes. Then, use a BBQ lighter to get all of the O2 out of the can. After that, you can quickly put the cap back on, and it works like a lightbulb (but you need a transformer from 120VAC to 12VAC at a few Amps.)

Haq3r00 (author)Xellers2008-12-19

when you say "use a bbq lighter" you probably mean a lit one that's creating Co2, not an unlit one that's packing out propane? curz that would just be a nerdy Molotov cocktail..... It would be fun though.....

About This Instructable




Bio: Just a bored teenager trying to have some fun.
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