In message <77A742979E2849FD9CA585192F2F5AFC@pc52>, "Tom Van Baak" writes:
>For tau 0.01 to 0.3 s it would take more work to quantify which pieces are >contributing to the instability pie. It doesn't really make sense to talk about taus less than approx 0.1s for Mains. It is not atypical to see 10% "harmonic distortion" on mains in a household, most of it from switchmodes, but also single-phase motors etc. Music amplifiers, in particular played at "teenagerockgod" volumes add a very interesting challenge too. In theory harmonic distortion does not change your zero-crossings, but it is not really "harmonic" in the Fourier sense, it's just mostly centered around the overtones. Either you include the "harmonic" distortion, and then your measurement applies only to that specific outlet, when the dish-washer is running exactly 20 minutes into programme 3 and no kids listen to loud music. Alternatively you can put mains through a 40-60 or 50-70 Hz bandpassfilter to supress anything but the the fundamental, but what exactly do you measure then ? Once you get below about 1Hz, the most interesting thing you can do with mains is to sample it at ~4kHz, make a water-fall plot and try to identify your house-hold appliances by their distortion patterns :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
