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Positive Van de Graff Generator? Answered

I know that a Van de Graaf Generator creates a negitive charge if you use a rubber belt, But how would one make a positively charged friction style van de graaf generator? What materials would you use?

5 Replies

kelseymh (author)2017-09-10

You may wish to look into the pelletron, which is a low energy (MeV) particle accelerator based on the van de Graff principle. It can produce beams of protons (hydrogen ions) and heavier ions (positively charged particles).

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Jack A Lopez (author)kelseymh2017-09-24

I forgot to mention the dirod machine. This is another electrostatic machine, that can, and has been, built by amateurs, and is capable of producing high voltage DC electricity.

Like the pelletron, there are other electrostatic machines that use electrostatic induction, rather than a triboelectric effect, to separate electric charges and move them apart.

The Wimhurst machine is well known. My high school physics classroom had one of these, and there is a Wikipedia article titled, "Wimhurst machine"


There is similar, but less well known, machine named, "dirod". This word, an abbreviation of the words "disk and rod", was coined by the machine's inventor, A.D. Moore.

I think the first place I saw pictures of the dirod machine (and I've never seen one in real life) was on Kevin Dunn's "Caveman Chemistry" web site,


and there are other web pages with dirod machines out there. Probably the best way to see several at a glance, is by doing an image search for, "dirod electrostatic generator"


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Jack A Lopez (author)kelseymh2017-09-11

There was a nice animated gif of a pelletron, on one of pelletron.com's old pages,


that seems to be missing from their current pages,


For the convenience of everybody, I'll try to attach a copy of that gif to this post, here:

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JohnM703 (author)2017-09-11

I was more asking how to turn one of these into a positive van de gradf

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