I am testing some theories for the production of carbon nano tubes using the Arc discharge method. Long story short, I need an AC supply of about 100 amps and approximately 20 Volts to vaporize the graphite electrodes.

I look at this and immediately think transformer. I can use one to step down the voltage and in turn raise the current. I am familiar with the formula. Assuming I have a fairly accurate 120Volts AC from the wall with 20 Amps, I would need a turns ratio of 5:1 to produce 100 Amps at 24 volts. I also know that I should put a 20 Amp fuse at the plug.

However I understand the extreme safety risks that are involved with high current and I recognize that this is a lot more than enough current to be fatal. That is why I want the thoughts, opinions and recommendations of you guys before I end up blowing myself up. Or am I looking at it completely wrong?

Thanks in advance

 

I would be more worried about touching the primary side of this transformer.

24V is not high enough to give you deadly shock, unless maybe you are touch both ends with bleeding hands. (direct body fluid contact)

The main danger with low voltage/high currents is exactly what you want to do: arc creation. Since you do not want an arc where there should be none you have to make sure to use the properly rated cable gauge, the right terminals and properly tightend srews where this current flows through.

You should use safety glasses. I would personnally also use gloves too, to protect against possible burns from unexpected arcing.

 

Sounds like what you need is a welder. My Lincoln 225 amp welder has a secondary voltage of 26 volts if I'm not mistaken.

 

Thanks for the tips. The arc itself will occur in a sealed chamber (if all goes well), but those precautions will be taken.

The welder seems like a good idea. I don't know why I didn't think of that. I will definitely look further into various welder schematics, but just at face value, what benefits would there be with using a welder circuit (or similar) rather than just building a transformer (assuming there is more to a welder than a transformer)?

 

Don't think you could build a efficient DIY transformer of that size for the price of a welder.

 

Don't think you could build a efficient DIY transformer of that size for the price of a welder.

About how big would this transformer have to be?

 

Look at arc welders they weigh 75 to 100 pounds or more. You won't get 100 amps from a 120V circuit. http://www.homedepot.com/buy/lincoln-electric-ac225s-arc-welder-k1170.html#specifications

Maybe you could make your "chamber" and find someone that has a welder that you can try it out with, before buying one.

 

Can't help but, "Carbon Nanotubes." Cool. If you can figure out how to weave them into a fabric, you could get rich in the first round.