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----- Original Message ----- From: "Mike Richter" <[log in to unmask]> > At 03:05 PM 3/5/2004 -0500, Steven C. Barr wrote: > > >Aren't all the electrical systems in North America synchonized at an exact > >60Hz, in order to avoid various spectacular results when they are > >interconnected > >(which is often the case)? I have ni idea how this is done, but I think I've > >been told it was/is done... > >Steven C. Barr > > They are not precisely synchronized. However, at least in the U.S. there is > an adjustment each night to ensure that precisely 60x60x60x24 cycles > transpired since the last one. > > Precise synchronizatin is not possible since the signals pass along wires. > They travel at about the speed of light in vacuo, but even so if they are > in phase at one point of the grid they are out of phase at another > junction. Think of it as one grid being U-shaped between two nodes and > another grid connecting at those same nodes being straight. While the > result might be a phase error of only a fraction of a degree, the > connections cannot depend on the signals being in phase or even precisely > at the same frequency. > > Though all that was explained to me by someone who knew, I did not have the > sense to ask how the tricks were pulled off. > Hmm-m-m-m...kinda makes sense, but let me see. I'll do this in meters to make the math easier (besides, as a Canadian I have to!)... Electicity travels at approximately 3*10^8 meters/sec (300,000,000). This means if the paths were different in length by 300 km (300, 000 or 3*10^5 m) there would be a difference of 1 millisecond. This puts the two waveforms out of perefect sync by one part in a thousand...or .36 of a degree (assuming the generators were in sync). Will this have any effect on AC devices? ...stevenc