[time-nuts] Simple AC mains zero-cross detector
r3m1g4 at verizon.net
Thu Dec 18 17:59:30 EST 2014
There is an interesting article in the Nov/Dec issue of Inside GNSS
describing the robust measurement of "...voltage and current phasors at
widely dispersed locations in a power grid". A Phase Measurement Unit
measures and time stamps the voltage and current phasors "...thousands of
times per second..." to an accuracy of <1 us using GPS. The authors discuss
several strategies for dealing with jamming and spoofing of the civil GPS
signals. It's a good read.
From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Hal Murray
Sent: Wednesday, December 17, 2014 3:28 AM
To: Discussion of precise time and frequency measurement
Cc: hmurray at megapathdsl.net
Subject: Re: [time-nuts] Simple AC mains zero-cross detector
csteinmetz at yandex.com said:
> That one is not ideal for this task, because (i) its output pulse is
> symmetrical about the mains zero cross, and (ii) the hysteresis zone
> is not well characterized and will drift with temperature and input
> voltage. So, there is no edge that is well characterized in relation
> to the AC mains zero cross.
What are you going to do with data from the line accurate to 1 microsecond?
These are my opinions. I hate spam.
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
and follow the instructions there.
More information about the time-nuts