Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

I used to have one of the FNET units to help them with data and to keep track of things myself during a period of low voltage in the summer months. The lowest voltage I saw was about 70 volts. Months of contacting ComEd directly with the excellent data provided by the unit accomplished nothing. An

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Now I'm getting interested in this. My concept is to take the 60 Hz in, do reasonable HW filtering to knock off the HF junk that commonly rides on the sinewave, then use an RC quadrature phase splitter to yield I & Q signals. Then sample at 1PPS with my Rb's PPS as the sample trigger, and

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi Andy, On 03/11/2018 08:40 PM, Andy Backus wrote: > Thank you for your posting, Magnus. > > Your information is very interesting. > > Do you mind saying a little more about the "incident" on 26-JAN-2016? I > don't find reference to it in the link. And my own TE plot for then shows no >

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

> “Back in the day” we used WWV and the kitchen clock for that sort of thing…… Bob, Yes, not much has changed. I use multiple methods to measure 60 Hz in order to gain confidence in the results. Besides the picPET, I've used a commercial TrueTime TFDM (Time/Frequency Deviation Meter) and also

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi If you pick the “right” STM board, it can handle processing up around a megasample. It’s internal ADC’s are more of an issue than the sample rate. You can only do just so well on harmonics with a 12-ish bit ADC. Even if you go crazy and get one with a display, they still are pretty cheap.

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi, On 03/11/2018 11:25 PM, Tom Van Baak wrote: >> In short, the GPS to UTC time correction polynomial got screwed up. > > Yes, that was an exciting time! > As far as monitoring mains phase -- a 13 microsecond step would be lost in > the normal jitter and drift of power line timing. My 60 Hz

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi Cute !! It certainly beats firing up an R-392 to see if you can get a tick from WWV… Bob > On Mar 11, 2018, at 5:42 PM, Tom Van Baak wrote: > >> “Back in the day” we used WWV and the kitchen clock for that sort of thing…… > > Bob, > > Yes, not much has changed. I

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

On Sun, 11 Mar 2018 14:41:23 -0500 Dana Whitlow wrote: > I'll have to take a look around to see if there isn't something cheap that > can run > standalone so I don't have to tie up (or wear out) a whole PC for the > acquistion > process. Blub... I should the whole

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

On Sun, 11 Mar 2018 14:41:23 -0500 Dana Whitlow wrote: > Now I'm getting interested in this. My concept is to take the 60 Hz in, do > reasonable > HW filtering to knock off the HF junk that commonly rides on the sinewave, > then use > an RC quadrature phase splitter to

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi, On 03/11/2018 12:53 PM, Bob kb8tq wrote: > Hi > > So, how good is “good enough?”. My first attempt ran a counter with a 1 us > period resolution. > (remember, it was tube based …). That turned out to be major overkill in > terms of line frequency > measurement. 60.123 Hz is doing pretty

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

I like the sound card idea. However I believe it's much better to use the two channels. At least under Windows, it is much easier to track the relative phase of the two channels of one sound card than the absolute phase of one channel compared to the system clock. I have written an audio VNA in

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Thank you, Bill. Your comments on noise I find interesting. I have tracked the TE of the Western Interconnection for 2-1/2 years now. For reliability's sake I use three separate systems that count in different ways. Transients are my biggest problem. I use low pass filters and optical

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi, I'd like to add two things: On Sat, 10 Mar 2018 20:46:16 -0800 "Tom Van Baak" wrote: > 1) Safety. I usually use a low voltage step-down transformer. This gives > isolation and safety. Anything from 3 VAC to 24 VAC is fine. Please, do not just add a transformer. Make

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

> In short, the GPS to UTC time correction polynomial got screwed up. Yes, that was an exciting time! For newcomers to the list, the bizarre GPS 13 microsecond jump was a hot topic on time-nuts back in 26-Jan-2016. The thread starts with an observation by Paul Boven:

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi So, how good is “good enough?”. My first attempt ran a counter with a 1 us period resolution. (remember, it was tube based …). That turned out to be major overkill in terms of line frequency measurement. 60.123 Hz is doing pretty well in terms of line frequency. Even to get that level, you

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

My 20 year old Junghans`s had no problemBert Kehren Palm City Florida Sent from my Galaxy Tab® A Original message From: Tom Van Baak Date: 3/11/18 8:32 AM (GMT-05:00) To: Discussion of precise time and frequency measurement Subject:

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Hi “Back in the day” we used WWV and the kitchen clock for that sort of thing…… Bob > On Mar 11, 2018, at 8:32 AM, Tom Van Baak wrote: > > Bob, > > Correct, measuring mains frequency to a couple of digits is not hard. What > makes an interesting challenge is to monitor

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

Well, this synchronization follows the laws of physics. If the energy generated doesn't equal the energy consumed, then the frequency may raise or lower. This is for steam turbines. If the energy come front an inverter from a DC tie line, as it does from the four regions in the US, the frequency