On Wed, 7 Apr 2010 12:51:57 -0700 (PDT), harry
wrote:

On Apr 7, 3:51?pm, Ivan wrote:
On Apr 7, 8:36?am, " wrote:

AC was adopted in the US because its easy to transport, stepping up
and down voltages to send current cross country.

thomas edison prefered DC, thinking it was safer

Thomas Edison preferred DC because he built his power system on DC and
AC was developed by a competitor (Tesla, working for Westinghouse).

AC is in fact more dangerous. When you say 120 volts AC, that is only
the RMS voltage (a kind of average) The peak voltage is nearly
200volts.

170V

The 120 volts AC will give exactly the same watts output as 120volts
DC if connected to the same resistor. But the 200 volts (peak) is
clearly more dangerous.
So Edison was right.