Van de Graaff device and common sense in physics ...

On Wednesday, May 27, 2015 at 9:45:33 AM UTC-7, George Herold wrote:
On Wednesday, May 27, 2015 at 2:51:54 AM UTC-4, whit3rd wrote:

Look carefully at the pelletron diagram: the pellets aren't charged from
HV supplies, they're induced ( by HV electrodes that never touch, nor
draw current); the current all comes through the drive drum, and ammeter "A".

https://jrm.phys.ksu.edu/Resource/Pics/Pelletron/28-ELEC_SCHEMATIC.jpg

This is a nice pic.
http://www.pelletron.com/charging.htm

I don't quite see how the induction works at the top.

It seems to be an induction electrode so that the charged pellets don't arc when they touch the
drum, but drain their charge gradually as they pull away from that electrode.
I think it's called a suppressor because it suppresses the arcing/current surge. The electrode
only needs to stay charged against leakage currents, so there's no arcing when its
pickup roller impinges on the links. And, of course, you can use two electrodes with the
same kind of pickup and induction, to do the up-belt and down-belt sides. On the
down-belt side, it's just like the induction at the base. Meanwhile, at the base,
the down-belt is induced by that second driven electrode, which prevents arcing
of the down-belt pellets, so they drain to the drive drum only as they pull away
from the 'suppressor'.

If this is correct, the best setting of the (base) suppressor would be slightly lower voltage
than the (base) inductor voltage, to account for leakages.
 

Welcome to EDABoard.com

Sponsor

Back
Top