On Wed, 31 Jul 2019 17:47:13 +1000 Erik Christiansen <dva...@internode.on.net> wrote:
> On 30.07.19 11:34, rhkra...@gmail.com wrote: > > Most residential power in the US is created using a single phase > > transformer (so called because (1) it only takes power from one of > > the 3 phases mentioned above and (2) darn -- it's a bitch getting > > old. > > Tell me about it. ;-) I'd offer that (2) is simply that there's only > one primary and one secondary, not three of each, on multiple arms of > the core. > > > The secondary of that > > transformer is center tapped with the center tap almost always > > grounded, such that the other two taps from the secondary both > > produce 120 volts (RMS nominal), but out of phase with each other > > by 180 degrees. > > Those details on this thread have been interesting, because 120v is > unknown down under - and, I think, in the UK. > We use it for tools on construction sites, hopefully through isolating transformers. I had some trouble getting permission to use a 240V soldering iron inside a train factory in the UK. -- Joe
