Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: mist maker / electrostatic motor



Leigh wrote:
... My favorite electrostatics demos are the demountable
Leyden jar and the simple electrophorous.



What do you do with the Leyden jar and why is it a favorite? I have a
Leyden jar in my lab (was here when I arrived) but I have never done
anything with it other than say "Look! That's a Leyden jar and it was used
historically to store charge."

The first thing you can do is charge it with the vdG. A demountable
Leyden jar has rigid inner and outer electrodes. It can be diassembled
into three pieces. If this is done after charging it, the electrodes
may be neutralized completely. When they are restored to their original
positions inside and outside the jar (which can be accomplished by
gravity alone) it will be found that there is a significant residual
charge left. I learned about this in about 1950, when I started
replacing TV picture tubes for my neighbors. I always accompany the
demonstration with a safety warning about old, supposedly harmless
discharged CRTs in TVs and monitors.

The scientific supply houses sell demountable Leyden jars. We made ours
in the glass shop here at SFU. It has more glass in it than the ones we
could buy, and it is likely more dangerous, too.

Leigh