On 5/25/07, Randall Nortman <[EMAIL PROTECTED]> wrote: > I would like to measure mains voltage (110-240V, 60Hz), but I want my > measurement circuit to be isolated from the voltage being measured. I > am going to be sampling the waveform at a high sample rate (relative > to the 60Hz waveform being measured) and comparing that with the > current on the same lines with (near-)simultaneous measurement. So it > is important to me that the voltage waveform not be distorted or > phase-shifted, and the voltage I see should be related to the source > voltage by a simple linear ratio. > > Seems like a simple transformer will do it, in theory. But I'm not > sure about how they will work in the real world. Do transformers > distort the voltage waveform or phase? What happens if I put a load > on the secondary of more than a few nA? What non-linearities are > there? What sort of transformers are going to give me the best > response?
There was a Watt-Hour Meter article in the April 2002 issue of Poptronics. The voltage measurement transformer was a Tamura 3FD-216. For current measurement a Coilcraft CS2106 transformer was used. (* jcl *) -- http://www.luciani.org _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user