Richard wrote:
Long distances need high voltage and AC. I suspect Nikola Tesla was a Roma from Jugoslavia, since my Gypsy friends, Roma from Jugoslavia, know his name and his profession and claim that he was a Roma. Dunno, but since their general knowledge isn't profound, there must be a reason that they especially know Tesla. I believe that three-phase AC could have to do with Siemens, I've got no idea what role was played by George Westinghouse. I won't read the Wiki.I suggest you all check on the high voltage feed from Canada in to the New York region. 0Hz
As I recall, Edison was busily building DC-based electric systems, while Westinghouse was building AC systems modelled after systems being deployed in Europe. Tesla invented and held some fundamental patents related to AC power and went to work for Westinghouse for a while. Meanwhile Siemens was one of the early and big players in Europe, starting out building telegraph lines.
The benefits of AC mostly come from being able to step-up and step-down voltages through transformers (transformers don't work with DC) - it's what makes long-distance transmission feasible (high voltage translates to low current and low resistive losses). Long-haul DC keeps threatening to make a comeback in the form of superconducting transmission lines (an alternate way to minimize resistive losses) - but that begs the question of how to keep everything cold.
Interestingly, when I was a kid, we inherited a relatively old B&W TV set from my grandmother. The specs said explicitly "110 volts AC/DC" - there were parts of NYC that were wired with DC, fairly late into the 1930s and maybe the 40s (I had to check, the first TV stations went on the air around 1928).
Miles Fidelman -- In theory, there is no difference between theory and practice. In<fnord> practice, there is. .... Yogi Berra