DC is used for very high voltage (1 MVolt+!) long distance power transmission. For one thing, it avoids the skin effect. Bob Ammerman RAm Systems ----- Original Message ----- From: "Tal" To: Sent: Saturday, April 26, 2003 1:49 PM Subject: Re: [OT] Saftey issues: AC vs DC > The main problem with DC is that it is difficult increase/decrease its > voltage and therefore, it cannot be transmitted efficiently over long > lines (the old Edison vs Westinghouse debate > http://www.raintaxi.com/online/1997fall/bloodvolts.shtml). AC allows you > to transfer the same amount of electrical power with less loses on the > wires(high voltage, low current). > > There are special cases when high power DC system are used (e.g. > conventional submarines with huge banks of batteries and voltages in the > range of hundreds of volts) but I don't think any country uses DC for > power transmission. > > As for danger, I think that if you compare DC and AC of the same voltage > rating, AC is more dangerous because the actual momentary voltage can go > higher than the DC. This is because the AC voltage rating is typically > done by RMS which is kind of a average and is lower than the max peak > voltage. > > Hope this helps, > > Tal > > > -----Original Message----- > > From: pic microcontroller discussion list > > [mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of John Pearson > > Sent: Saturday, April 26, 2003 6:46 AM > > To: PICLIST@MITVMA.MIT.EDU > > Subject: [OT] Saftey issues: AC vs DC > > > > > > Is it true that DC is more dangerous, electrocution wise, than AC. > > > > Is it true that some countries use DC? > > > > If so, what is the voltage? > > > > Thanks > > > > John > > > > -- > > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads