Instructables

What is wrong with my VDG?

i have just finished my small van de graaf generator but have run into a problem. I am only really building this small one as a model for my future large VDG so it is not to important, I would just like to find out more. My setup consists of two wooden dowl rollers built up with tape to "bevel" them. the bottom roller is coated with paper while the top is coated with teflon tape. the belt is a section of rubber balloon. the tube is a PVC pipe which is split so i can easly open it up and make ajustments. i have found this setup to be very good and can often achieve 2 CM sparks whith only a beer can as a top load. The problem is after about 5 miniunts the output will slowly decline untill I can no loger get any sparks. when this happens i have to open up the PVC coulom and clean the belt and rollers with an alcohol wipe. After wards, the machine continues creating 2 CM sparks until i have to clean it off again. I do understand the fact that dirt will be attracted to it and that enough dirt can bleed the voltage away but i do not think this is the case as i clean it so often and it is all sealed up. I just wanted your feed back because it is becoming tedius and i am starting to wonder weather it will affect the larger van de graaf.

Thanks In Advance

SCIENCEPAL2 years ago
http://www.instructables.com/id/Van-de-Graaff-Generator-made-from-junk/

Try this link!!!

Hope it helps!!!!
mcraghead2 years ago
Have you tried shooting it with a hair dryer? Dropping the humidity could help, and maybe the cleaning could be secondary to the break that the VDG is getting? Have you just left it sitting for 10 minutes and then tried again? Also: if you put a ground wire in the mix you might be able to get a fresh supply of electrons (see step #5: http://www.instructables.com/id/Mini-Van-De-Graaf...-M--M-style/)

Good luck!

Mike

werewolf9002 years ago
There could be a short or the wiring could be messed up.
Kiteman2 years ago
What are you standing the VdG on, what sort of surface or table?

Are you letting the sparks jump to the base?

It's possible that your "cleaning" is just allowing built up charge to ground through you.
MadScientist101 (author)  Kiteman2 years ago
It is standing on a desk made of laminated wood in my bedroom.

The sparks are either jumping to my wrist or a grounded aligater clip.

What do you mean ground through me?
If the VdG is collecting charge on the lower dome, then it might be leaking away through the desk (wood is great at insulating high voltages).

~or~

Charge is being transferred from the lower dome to the belt, but not all of it is transferred from the belt to the upper dome, then the belt may reach a point where it can carry no more charge. When you clean it, maybe the charge flows through you to ground, allowing more to be transferred.

This might be easier to diagnose if you could post images or a video of the VdG.
MadScientist101 (author)  Kiteman2 years ago
Do These Help?
2012-02-04 09.59.48.jpg2012-02-04 10.00.23.jpg2012-02-04 10.01.13.jpg2012-02-04 10.01.51.jpg2012-02-04 10.02.17.jpg