Re: 240 V.

>> In addition, since 240V is really two 120V lines with a 90 
>> degree phase difference, 
> Ummm.... 
> Just to split hairs, the phase difference is 180 degrees between the 
> two phases (for "single" phase power)
> Chip

Whoops...this was a case of the fingers being in gear before the brain 
was properly engaged.  A 90 degree error is not really "splitting hairs" 
but I did mean 180 rather than 90 (i.e. - the lines are mirror images of 
each other wrt/ground, one side goes positive as the other side goes 
negative).  Thanks for pointing that out.

Steven Roys (sroys-at-radiology.ab.umd.edu)