Question on AC vs DC

[Shannow]

Edison's stunts were simply that...stunts to make people think that one was safer than the other (well more to the point that HIS was safer). In terms of system design, Edison backed what was always going to be the loser.

 

[brianl703]

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Just incase their might be some on here that do not already know your alternator on your car generates AC and use's diodes to simulat DC. The battery on the car is basicly a huge electrolitic capacitor and is used to filter this dirty simulated DC signal.

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Crutchfield suggests that if you have an alternator noise problem in your sound system, you might be able to fix it by adding water to the battery if it's low.

I'd never heard that before.

 

[eljefino]

DC doesn't travel well over long distances.

Edison wanted DC to be the standard so he could have a (presumably licensed) power generating plant every 2 miles.

If you double the voltage and halve the current, you get the same work done, but need less copper in the conductors. This inspired cars to go from 6 volts to 12 in the 50's and is inspiration for the 36/42 volt systems proposed. Apparantly the Prius runs yet higher voltage but has safeguards in place due to the >50 volts being "more dangerous".

 

[brianl703]

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DC doesn't travel well over long distances.

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The problem is that DC can't easily be changed to higher or lower voltages. With AC you need only a transformer. That being said, there is a such a thing as a High Voltage DC link (HVDC), one advantage of which is that it can be used to interconnect parts of the elctrical grid that aren't synchronized (such as western USA to eastern USA, or Texas to Western USA, etc).

HVDC uses technology that was developed in the 1930s.

http://en.wikipedia.org/wiki/Hvdc