[Shop-talk] need name for odd device found in shop

[Wayne]

Pat wrote:
> I don't remember what it is called, but it is used to demonstrate 
> magnetic coupling. An AC voltage is placed across one of the coils (I 
> think the terminals on the base) and an AC volt meter is placed across 
> the terminals on the top. As the core (rod in the center) is withdrawn 
> the voltage reading will decrease.

Sounds reasonable, though I can't think of any useful application for 
it.  The effect is just simple inductance, or inductive coupling.  Maybe 
it's some science fair or classroom type of demo device?

   -Wayne