[time-nuts] 60 Hz line quirks, anybody recognize this stuff?

J. Forster jfor at quikus.com
Tue Sep 4 00:36:14 UTC 2012


At a quick look, those look plausible line transients. However, the actual
plots look badly undersampled during the transients. The plotted results
in the transient areas are pretty meaningless, IMO.

YMMV,

-John

============



>
> Thanks for all the hints and suggestion.
>
> The problem seems to be anRS-232 receiver.  I haven't seen any glitches
> like
> those since I moved the PPS line to a different PC.
>
> Has anybody seen anything like that before?
>
> Anybody got any ideas on how a receiver can turn into a driver?  The
> typical
> level shifters have separate receivers and transmitters rather than a
> tri-state and enable.  Maybe I'll take it apart and see what chip it uses.
>
> There is a 1K resistor in series with the output of the wall wart so it
> makes
> some sense if a current/slew limited (aka weak) driver got turned on.
>
> Looks like I got a lemon in that box.  (That's the box that has crazy
> stuff
> on the audio input like this:
> http://www.megapathdsl.net/~hmurray/time-nuts/li
> ne/2012-Aug-07-a0.png)
>
> Anyway, I'm back to looking at things that seem reasonable.  Sometimes,
> glitches happen when the line voltage changes.
>
> Here are a few graphs:
>
> Here is a sample voltage change:
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-02-b0.png
> These are the beginning and end of the above:
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-02-b1.png
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-02-b2.png
>
> A pair of glitches that were close together:
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-02-c0.png
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-02-c1.png
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-02-c2.png
>
> Isolated glitches:
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-02-a0.png
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-03-a0.png
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-03-b0.png
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-03-c0.png
>   http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-03-d0.png
>
> --
> These are my opinions.  I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>






More information about the Time-nuts_lists.febo.com mailing list