User-agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1
It wouldn't be hard to do an experiment. If you remove the globe (or
not) you can measure the charging current with a microammeter. Then run
the VdG at several spacings of the collectors. You will get something
around 20uA. Interesting subject.
--- Carl
On 8/25/2018 7:47 PM, Antonio Queiroz wrote:
Em 25/08/2018 15:13, doug escreveu:
while we are on the subject of Sparks, I have a question using my
VDG's as an example. The pickups on most VDG's sit slightly away from
the belt and in dim light one can see sparks going off the belt to
the pickups. Am I wrong in believing that some energy gets dissipated
as the sparks cross to the pickup from the belt? On my VDG's I use
conductive poly film resting on the belt for the pickups and it works
very well.
Doug
Certainly there is energy loss in the corona. There is a drop of at
least several hundreds of volts between the belt and the pickups. With
microamperes of current a few miliwatts can be wasted (1000 V at 10 uA
= 10 mW). Brushes touching the belt waste less power.