Van de Graaff Video, Parts, And Higher Voltage Tips!
Quick Note: Nuts
& Volts readers, please
excuse the hasty nature in which this page is being assembled, The last
few weeks have been extraordinarily busy, including having been lucky enough
to build an energy display for the LA County fair (opens 8/31/12) and working
on several other interesting projects.
I plan to ADD to this page in the near future, including videos of the devices working that you can check out, and two or three really really awesome electrostatic toys you can make for LEVITATION! So, I hope you will continue to check back for those. For the moment, I'm just going to quickly put up the extra info promised in the article so your generators will be humming at MAXIMUM in no time!
First: As mentioned, there are some very useful equations for calculating the capacitence of leyden jars and top potentials. I have a very ancient program (free of charge) which I wrote for Tesla Coil design which features these equations at: http://www.noonco.com/tesla/
This program is an old DOS program with CGA graphics (yikes! does anyone remember those?) but the equations work just great, and amazingly it still seems to run on my "modren" computer. In the future I'll copy those equations over to this page , and try to add a flash based calculator to do them from the page.
Second: I mentioned commercially avaialable belts. I think Amazon actually has better prices than buying from the scientific houses directly. Here is a great Amazon page with parts: Amazon Van de Graaff Parts Also at Amazon are the rubber belts for making your own home made belt. I think these actually work BETTER than commercial belts, and cost a lot less, though you do have to cut and assemble them yourself: Rubber belts
Third: I wanted to talk about HIGH POWER and rapid charging for your generator! But, before mentioning this, I do want to say that with your generator as described, you will already be able to get sparks of several inches, and one builder already mentioned getting a spark of more than 10 inches! SO, keep in mind that for a Halloween or science demonstration your generator is probably perfect. But, if you're in the mood do run a home made atom smasher (quite possible to do!) here is a great trick: If you use a metal roller top and bottom, it's possible to "spray" electrons onto the rubber belt with a 10kv power supply. You'll need to rectify the output of your 10kv supply to DC, and to connect it to the lower brush, then ground the lower roller. This makes charge pick up very fast, and can be used for pumping a larger top sphere! If your top sphere is larger than 9" in diameter, it will no longer be safe in this configuration except for labortory work! But, it does sound like fun. :-) A detailed article is here: Externally excited Van de Graaff
Thoughts: There are many great books
with electrostatic devices and experiments. One book I wrote just out
of highschool seems to be still floating around and I found it on Amazon here
if you happen to be interested.
I think it's a great book of quirky simple projects especially good for
a science fair or a young person interested in electronics.
And a last Halloween thought: My 12 year old son Mackenzie was just theorizing as to why Dr. Graaff invented his generator. According to him:
"Physicists like Einstein typically had very messy
hair. Van de Graaf invented it to get his hair to stand on end, making
it easier to cut. He had hoped to be a millionaire in barber
shops cutting physicist's hair. But alas, all his dreams were dashed when the first bolt lept
from the comb killed his first subject.
Fortunately, he was not charged with murder as the body was never recovered.
Some say it still wanders the earth."
Thanks very much!
Write me at: noonco.com
Some say it still wanders the earth.