OT: OT: OT: Van de Graaff generator

Make sure to wear hearing protection when making lightning bolts. Do not ask me how I know.

The 1x30 Delta belt sander makes a good Van de Graaf generator with no modifications.

Are they actually legal in the US after 9/11. I was told by a guy that was involved in building one in Hawaii recently that they got told they were no longer allowed due to the potential for screwing up radio communications, this was after they had cranked it up and apparently affected the local station output on campus.

Did they outlaw natural lightning too?

Couldn't say as I live in the UK and don't follow whether congress tries to outlaw acts of God.

Re my previous post I was just talking to a Hawaiian guy when he was in the UK and we got talking about tesla coils and the like and he mentioned that they got told off for running one after 9/11 , as not allowed anymore.

Well, actually, tesla coils have been illegal since 1934 in the US, at least under some circumstances. If the thing resonates at the frequency of some communication channel (and mid-sized Tesla coils could easily run up to the low TV channels) then they will interfere with licensed communications. If you are generating big arcs with the HV output, then it will be radiating at all sorts of harmonics up into the UHF.

If it isn't arcing the HV, then the RF output shouldn't be a whole lot worse that a big welder with an HF system. Those aren't illegal, per se, but you might have to do something if it is interfering with communications.

Jon

Jim,

Please give us more information re. the belt sander Van de Graff generator. I have a 1 x 42 belt sander -- will it work?

Bob (unshocked) Swinney

The 1x30 Delta belt sander makes a good Van de Graaf generator with no modifications.

Thanks for that, I guess they had it radiating as it apparently effected the local campus station somewhat. Reminds of playing with basic spark gap units using a relay when I was a kid, that effected AM somewhat. Also an older mate told me of when he was a kid and he rigged a variac to a ignition coil and ran it off the 240V mains, he said his mother came in wondering what was up with the television and saw the coronal glow around the coil.