Hector Martin wrote: > 1. Americans are wussies. Real men use 220V :) While this may be... > 2. (more likely) 110V is older. Once people realized it would be too > wasteful (thicker wires, etc), other countries started using 220V. > America (and Japan) probably already had plenty of 110V appliances, so > it stuck. ... this one is probably not correct. I'm not sure whether there is in fact evidence that the USA (definitely not Japan) had historically an edge on electrification compared to the earlier 220-240V countries. E.g. in Germany the process occurred pretty much at the same time as in the USA: in the last years of the 19th century. Here they trace it back to Tesla vs Edison, Tesla favoring 240V AC and Edison 110V DC. Interesting also . The one information they left out in this page is the phase system. FWIW, the smaller wire sizes in 230V countries are quite easily recognizable when working with electrical installations :) >> Also I've heard of people taking the other half wire of a 220v supply and >> discarding the other.. and using ground as the other half to convert to >> 110v... a bit dangerous I think... > > In 110V areas, it's common for transformers to put out two 110V phases > out of a single winding, tapping the neutral at the center. If you > discard the neutral wire and use both 110V phases, you get 220V. In 230V areas, I think 3-phase is more common (at least in the EU). 230V is then the star voltage from phase to ground; phase to phase would be 400V. I find it practical to have a standard 3-phase system in the home (or in the shop); if you need a heavier motor, there's no need for workarounds or special utility contracts, you just connect it. > I don't think you can get 110V out of a 220V supply without a > transformer, except maybe placing two identical 110V loads in series. Yes... not recommended :) Gerhard -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist