On Sun, 2007-05-27 at 08:02 -0400, Randall Nortman wrote: > So now I have to figure out if I really care about those >60Hz spikes, > dips, and noise. I am thinking not, so transformers should be just > fine. Then again, the reference designs for these Analog Devices > chips just put a resistor divider between hot and neutral and feed it > straight in without isolation. They use neutral as DC circuit ground > and derive power from the hot line, so the whole circuit is tied to > mains without isolation. If I did that, I would of course have to > make sure that the digital interface between my measurement system and > the PC that captures the data is isolated, which is pretty easy. Any > thoughts on that setup?
Not a bad setup, but like you say, needs careful attention to isolation and insulation at appropriate points. Be careful with resistors, they have a voltage rating, so for mains work you may need more than one in series (in the high side of the divider) to avoid them failing open-circuit. Regards, Peter Clifton _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
