brightest home made light source?

[Paladin]

I grew up in an age when science education for young boys was still thought important. At 8 or 10 I was poking around inside TV sets and other fun stuff. Regular "projects" came in the mail from "The American Basic Science Club".

But related to "flashoholism", perhaps imprinting on my young mind a desire for lumens later in life, was the carbon arc lamp project. I was given instruction for salvaging carbon rods from old D cell batteries, and drilled some holes in opposite sides of a clay flower pot IIRC. The stripped bare ends of a lamp cord were wrapped around the exposed end of each rod.

The exciting part was getting it to light up, i.e. establish an electrical current flow in the gap between the two carbon rods. Imagine arc welding without metal rods. The power of the sun in a small clay pot, contrived and operated by a 10 year old.

Anyone else here ever experiment with carbon arc lighting? Actually, I think the original intent of my project was to use the device as a furnace, probably to melt the uranium ore the ABSC had sent me.

Paladin

[defusion]

well, i threw some magnesium powder together, and lit it. that was pretty bright. but i suppose thats not what you mean.

[Toohotruk]

Hmmm...sounds kind of dangerous...I might have to try it!

How long would something like this burn before the rods become too short? I imagine you wouldn't want to look right at the light source, at least without a welding helmet or something, right?

[Paladin]

Here's a link to a guy who was a little older than me, apparently exposed to the same subversive education process. His description is close to my experience, I forgot the fun part of touching the rod ends together to initiate the spark, and definitely was running my light/furnace at the full power of a 15 amp household outlet.

RESEARCH FIRST, PLAY LATER. It's incredible some of us survived childhood.

Paladin

carbon arc article:
http://members.misty.com/don/carbarc.html

[tinkerer]

I used to have a carbon arc torch that was run by an arc welder. Used it for brazing a few times. Its not used much anymore and pretty much obsolete. As in any kind of welding, any exposed skin should be covered because you'll get sunburned. A tig torch will give a nice steady arc without the sputter of stick welding.

[wakibaki]

Ah, yes, I used to do this when I was a kid.

The old style torch batteries (circa 1960) had a zinc case and a carbon rod centre electrode surrounded by a muslin bag that held manganese dioxide to keep it from migrating away from the electrode into the jellied electrolyte. For all I know you can still get these, but it's been a while since I busted open any cells...

Anyway you could get a couple of these electrodes, and if you had an old car battery or two, wire the rods to the electrodes on the car battery, and then bring them together (one in each hand) and then try to draw out the arc.

Of course it never used to strike for more than a few seconds with this kind of primitive arrangement, but it kept me amused for a while on more than one occasion.

I used to have stuff in my chemistry set, if they came round your house and found it now, they'd lock you up. Things weren't perfect then, but I miss a lot of things from those days, and I regret the loss of freedom.

w

[jtr1962]

I did something similar when I was about 15. In fact, I still have the carbon rods from the D cells which I used. I wrapped some wire around the ends of the rods, and connected them to a 30V, 25 A transformer. Holding the rods with pliers, I touched them momentarily to start the arc, then gradually pulled them apart. The sound of the transformer humming as it strained to power the arc was kind of cool. I actually eventually burnt out the transformer doing this! I remember I had to hold everything at arm's length to keep from getting burned. I also remember my eyes feeling itchy sometimes in the following days if I looked too long at the arc. I didn't use eye protection of any sort, so as a general rule the arc was much too bright to stare at anyway, except very briefly. It really lit up my small workroom! When I stopped the arc, the ends of the carbon rods were glowing white hot for a brief second, gradually cooling to orange then red. Lots of fun, although I dread to think how today's overprotective parents might react if their 15-year old tried something similar. In truth, it probably was far from the most dangerous thing I did. Riding between cars on the N train as it speeded through the 61st Street East River tunnel was another less than safe pastime I had at that age. Oh well, I'm still alive, and can still see well out of both eyes, so I'm glad I did what I did in the name of science.

[BVH]

How about two, 3/8" diameter carbon rods connected to a car battery. Talk about stupid! Boy, was it bright for a Nano-second until I couldn't see anything for a while. Thank goodness I didn't blow the top off the battery. "live' and learn.

[yuandrew]

Well, I also made a Carbon Arc lamp as well using pencil lead and drill batteries. Burnt my thumb doing that and melted some 18 gauge wires but it was extremely bright while it was running. It got too bright to look at after a second of striking the arc.
Even though none of it was connected to the "grid", it still created a lot of
TV and radio interference as well.

I also tried to make a mixture of magnesium shavings and some powder from a firework. Lit up the whole backyard for about 3 second when I burned it.