Hi,

Why is a Wimshurst machine never used for the static-electricity hair-standing up demo? It's more efficient than the Van de Graaff, and smaller too.

 

I have a Wimshurst machine and on a good day (when the humidity is low) I can get 3 inch sparks. These discharge from two capacitors (known as Leyden jars). I'm not sure how many volts it needs to get sparks like these but must be 100kV or so.

Not a good idea to touch!!

In fact, when I first got the machine the Layden jars were made of glass. One cracked with the voltage stress! Now they are plastic (polypropylene) and seem to be holding up.

 

I have a Wimshurst machine and on a good day (when the humidity is low) I can get 3 inch sparks. These discharge from two capacitors (known as Leyden jars). I'm not sure how many volts it needs to get sparks like these but must be 100kV or so.

Not a good idea to touch!!

In fact, when I first got the machine the Layden jars were made of glass. One cracked with the voltage stress! Now they are plastic (polypropylene) and seem to be holding up.

But if you don't use high capacitance Leyden jars then the person will be the capacitor, same as with the Van de Graaff.