scott wrote:

> Capacitors and inductors can STORE ENERGY!

No - really?

> What if I connected a vertical pipe several metres high to your pipe 
> network in the middle somewhere?  As you applied some external force 
> through your system, I opened up a valve for a second to let water flow 
> into my vertical pipe, then closed it.  You would notice a slight 
> increase in force needed. Then, once you switched off your external 
> force later, I open my valve and let my water flow back into the system 
> and it would force more water out the other end.
> 
> Would you be puzzled that after you switched off your force water kept 
> coming out for a bit longer?

No - because there is positive pressure at the value you just opened, 
and this pressure is what is pushing the water along.

Similarly, a capacitor can store charge such that when you turn off your 
external current source, the capacitor is still presenting a voltage to 
the system, and hence current is still flowing. There is no mystery in 
that. The mystery is in saying that there is actually "no voltage", and 
the current is just magically flowing all by itself.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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