Re: [time-nuts] Three Phase Power
Many of them include the ability to remotely turn off supply- something thats not so well known as its not had much use as yet... DaveB, NZ - Original Message - From: J. Forster j...@quik.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, June 28, 2011 9:49 AM Subject: Re: [time-nuts] Three Phase Power IMO, smart meters are a greased, very slippery, slope toward power rationing or fines for overconsumption YMMV, -John Will Bill, [snip] Centerpoint Energy has reached the epitome of laziness and is converting everyone over to smart meters so people can better monitor their usage... In reality it does nothing more than offer real-time monitoring for the power company, and they no longer have a use for meter-readers... ___ 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. ___ 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.
Re: [time-nuts] Three Phase Power
I remember experimenting as a kid, running small low voltage bulbs of the earth and neutral lines in our house. Rob K -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jason Rabel Sent: 27 June 2011 9:38 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Three Phase Power Will Bill, Our (commercial) three phase power is fed by only two high-voltage wires (7,200v I think) which each pole has a pair of transformers. I can only assume one generates the 220v single phase lines and the other is the high-leg delta. Around here 230v three phase delta seems to be more common than 208v Y style. I remember a couple years ago we had a transformer die (thankfully it was a passive failure and not a massive fireball on the pole). People were wondering why their machines weren't working (but the lights were on)... Sure enough hooking up a meter and the high leg was dead... I did read somewhere that this change might have an effect on demand meters? There was no further explanation unfortunately, but that does kind of worry me as I know about 90% of the meters on our property are that style. The power company just loves to tack on a demand charge to the bill, which can often double, or triple the cost of your electric... Just because you want to have the lights on, A/C running, and an air-compressor... :( I've never seen or heard of anyone here in Houston with three phase residential (except for farmers, but I guess they are commercial). Centerpoint Energy has reached the epitome of laziness and is converting everyone over to smart meters so people can better monitor their usage... In reality it does nothing more than offer real-time monitoring for the power company, and they no longer have a use for meter-readers... ___ 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. ___ 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.
Re: [time-nuts] Three Phase Power
Jim, No, when I bought the property, I rewired the entire building, all the way to the meter itself, so there was no chance of a leech. Also, I sold the building to a local concrete mfg., and they didn't have the keys until just after this happened. Plus, the boot insulates the meter from the connectors in the base, and it had the same unbroken seal on it, that I watched the guy place, as the power was disconnected that day. We think it happened here in our neighborhood too. Things weren't jiving right with our bills, and several of us starting making our own readings. We did this over six months, but when confronted, AEP claimed it was due to estimation, but the so-called reading was different from ours on each bill, and an estimation is supposed to be no longer than three months, or they told us. Next, I actually looked into the legality of placing an enclosure over the meter, with a lid on it, and the the reader would have to lift it in order to read it. If he had been there, and read the meter, it would show it by a re-setable LED burning inside the house. Now, you can buy dear cameras, and if somebody walks in front of the meter, you get a photo of it, but at the time, they weren't out. What we also found, was that we had the same meter reader here, that was supposed to do the area just up the road, where my shop was located. What several of us think, is that this meter reader, at the time of this, was out doing who knows what, and was using old meter readings that had been made, and just writing those down, while never visiting the meters. In a similar case, they caught a guy here, seeing his sweetheart, while supposedly reading meters for the water company, and he was fired. AEP, though, never investigated this, that we know of, and that was around 15 years ago, but we have no problems now, that we know of. Things like this, make me think, that these smart meters need to be policed, if we don't want to end up being royaly screwed. Making sure the timing is correct, on any of the meters, is the same as demanding calibration for any piece of equipment like scales, etc, and it ought ot be done more, since money changes hands. Best, Will *** REPLY SEPARATOR *** On 6/27/2011 at 7:04 PM jim s wrote: On 6/27/2011 6:33 PM, Will Matney wrote: snip I'll leave a parting shot at AEP on this. When I closed up the building I had the shop in, I went down to our AEP office at the time, and paid off my bill, the day after I had them to put a boot on the meter, and a new seal on it. It was read that day. Well, the next month, I get another bill, and I take it to AEP, and ask what's up, and show them a time stamped photo of the meter, with the seal and boot still on it. They had the audacity to tell me, that it still must have been something using the power, and the meter had been read, but it had never been tampered with. Now, you tell me what happened? I never paid that bill either. My guess, it all revolved around the meter reader. Best, Will If this was in a building with a landlord showing the unit, it may be that they never put the power back in their names, trying to be cheap bastards. Did you go back and read it to see if the meter had any power on it, or just take their word for it. Once you cut off your responsibility, it doesnt' matter much what they say, it is going to be their problem, not yours. The power company did nothing when I cut off service, and the power was still on for some days after I vacated, but my bill was last and final, and I don't know who got the bill for the extras. Other possibility is that you were being leeched off of all the time you were in the shop, and when you pulled out all your stuff, the leech was still hooked up. I'd actually be a bit more curious if this was the case, as I'd like to get back part of all of my billing for the entire time I was in the unit. Jim __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ 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.
[time-nuts] Fwd: BIPM Annual Report on Time Activities 2010
The following report just released by the BIPM may be of interest. It includes a section detailing all standard frequency and time broadcasts. -- Forwarded message -- Dear Colleague, The BIPM Annual Report on Time Activities containing the information for 2010 is now available on the BIPM website at http://www.bipm.org/en/scientific/tai/time_ar2010.html Best regards, Hawai Konate BIPM Time Department ___ 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.
Re: [time-nuts] Three Phase Power
Exactly. -John = Many of them include the ability to remotely turn off supply- something thats not so well known as its not had much use as yet... DaveB, NZ - Original Message - From: J. Forster j...@quik.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, June 28, 2011 9:49 AM Subject: Re: [time-nuts] Three Phase Power IMO, smart meters are a greased, very slippery, slope toward power rationing or fines for overconsumption YMMV, -John Will Bill, [snip] Centerpoint Energy has reached the epitome of laziness and is converting everyone over to smart meters so people can better monitor their usage... In reality it does nothing more than offer real-time monitoring for the power company, and they no longer have a use for meter-readers... ___ 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. ___ 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. ___ 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.
Re: [time-nuts] 60 Hz measurement party
At the suggestion of another member of the list I added a low pass filter to the input of the HP5370B and I also connected the door bell transformer to an un shared branch circuit. After making these changes noise in the readings seems to have gone away. - Original Message From: Jim Lux jim...@earthlink.net To: time-nuts@febo.com Sent: Mon, June 27, 2011 9:34:36 PM Subject: Re: [time-nuts] 60 Hz measurement party On 6/27/11 9:43 AM, Mark Spencer wrote: I'm not sure if the results I am seeing are valid or not. My signal source is a 16 volt doorbell transformer that feeds a voltage divider which in turn feeds my 5370B with an approx 2 volt sine wave. Setting the trigger point on the 5370B to 0 volts appears to provide the best results and the sine wave from the voltage divider looks to be clean on my scope. But I'm wondering if changes in line voltage could be confusing things. That's sort of why I was thinking of the sound card approach.. you sample it, fit a sinusoid, and get the zero crossing time from the parametric fit. Doorbell transformers have a lot of leakage inductance to limit the current (so that shorting the output doesn't burn it up) ___ 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. ___ 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.
[time-nuts] How does it work?
For the sake of this poor, befuddled non-engineer, would one of you worthy gentlemen explain how it is that lasers striking a mass of cesium atoms and compressing them into a ball (in a cesium fountain) has the effect of cooling them to near absolute zero? That seems counter-intuitive to me, but then I have virtually no education in this area. Thanks! Bill ___ 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.
Re: [time-nuts] How does it work?
I think the part you miss is that the laser does not have a conterminous pressure as in say a piston in a diesel engine. The function of the laser is to oppose the motion of the atoms, to prevent them from moving, some tuning is involved to make this happen. So it acts more like a sheep herder than a piston. The goal is to make the atoms motionless. Why? Remember that heat is equivalent to the kinetic energy of the particles. On Tue, Jun 28, 2011 at 9:55 AM, William H. Fite omni...@gmail.com wrote: For the sake of this poor, befuddled non-engineer, would one of you worthy gentlemen explain how it is that lasers striking a mass of cesium atoms and compressing them into a ball (in a cesium fountain) has the effect of cooling them to near absolute zero? That seems counter-intuitive to me, but then I have virtually no education in this area. Thanks! Bill ___ 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. -- Chris Albertson Redondo Beach, California ___ 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.
Re: [time-nuts] How does it work?
There is a useful paper describing this: http://optics.colorado.edu/~kelvin/classes/opticslab/LaserCooling3.doc.pdf Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of William H. Fite Sent: 28 June 2011 5:56 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] How does it work? For the sake of this poor, befuddled non-engineer, would one of you worthy gentlemen explain how it is that lasers striking a mass of cesium atoms and compressing them into a ball (in a cesium fountain) has the effect of cooling them to near absolute zero? That seems counter-intuitive to me, but then I have virtually no education in this area. Thanks! Bill ___ 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. ___ 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.
[time-nuts] TEC party file format?
I'm planning on counting 60Hz line cycles with some embedded hardware, then dumping the count over RS-232 every minute or so to a linux box running ntp. Any thoughts on what data to log? Obviously, the 60 Hz cycle counter. Timestamp when data was received at the serial port? (It looks like my box has the high-res timers, so I can get it down into fractional seconds pretty easily). Line voltage? Some of the NTP status? I'm thinking one line per sample, with commas as delimiters. Sound good? -- newell ___ 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.
Re: [time-nuts] How does it work?
Hello, Roughly, the temperature can be seen as a measure of the brownian motion (ie shaking) of the atoms. So if you keep the atoms at rest, it's equivalent to cooling them. One definition of the absolute zero is that there is no motion of atoms. HTH, Jean-Louis - Original Message - From: William H. Fite omni...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, June 28, 2011 4:55 PM Subject: [time-nuts] How does it work? For the sake of this poor, befuddled non-engineer, would one of you worthy gentlemen explain how it is that lasers striking a mass of cesium atoms and compressing them into a ball (in a cesium fountain) has the effect of cooling them to near absolute zero? That seems counter-intuitive to me, but then I have virtually no education in this area. Thanks! Bill ___ 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. ___ 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.
Re: [time-nuts] Three Phase Power
On 06/28/2011 08:16 AM, Will Matney wrote: Things like this, make me think, that these smart meters need to be policed, if we don't want to end up being royaly screwed. Making sure the timing is correct, on any of the meters, is the same as demanding calibration for any piece of equipment like scales, etc, and it ought ot be done more, since money changes hands. Being a former utility engineer and a closet meter nut (anyone else have a revenue meter calibration bench in his lab? :-), I thought I'd comment on this. Federal regulations require that smart meters be manually read once a year. That will re-sync things if the electronic reportage gets out of whack. That solves only one of the many problems with electronic meters. Let's say lightning hits hard enough to blow the meter apart. With the old mechanical meters, at least a last reading could be taken from the mechanical register. With the electronic meter, if the LCD is even still intact, it's just laying there blank. A client utility recently rolled out about 80,000 electronic meters with no pilot program or prior testing. It has been an unmitigated disaster. Over 10% initial failure rate, probably from infant mortality. Automatic reading has been spotty at best. The selected system uses a ZigBee-based mesh network which in a rural setting doesn't work very well. The utility has has to hire a contractor to handle customer complaints. I got a batch of 100 of the old decommissioned mechanical meters. I wanted to test them to see how accurate they are. Some are over 30 years old. I'm about half way through the batch and have yet to find one more than about 1.5% out. This is what I expected from past experience. The electrical Co-Op that serves me did it the smart way. They deployed the Turtle system. This is a system that retrofits to the mechanical meter with a photocell to count wheel revolutions. It sends the reading back over the power line using a modulation scheme that I have yet to be able to discover. They're pretty tight lipped about that. From what I hear from talking to the field engineers, this has been a highly successful roll-out with very few complaints. John -- John DeArmond Tellico Plains, Occupied TN http://www.neon-john.com-- email from here http://www.johndearmond.com -- Best damned Blog on the net PGP key: wwwkeys.pgp.net: BCB68D77 ___ 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.
Re: [time-nuts] How does it work?
You may be confusing a fountain and an ion trap with LASER cooling. In an ion trap, the ion is in a potential well and interacts with the cooling LASER beam which slows the ion down (in all 3 directions), thus cooling it. The slower moving ion has less Dopplar, hence a better frequency standard. In a fountain, the ions sort of come out of a gun and they are probed orthogonal to their flow direction. Because the beam is near collimated, the sideways Dopplar is reduced a lot. All very roughly speaking. -John == For the sake of this poor, befuddled non-engineer, would one of you worthy gentlemen explain how it is that lasers striking a mass of cesium atoms and compressing them into a ball (in a cesium fountain) has the effect of cooling them to near absolute zero? That seems counter-intuitive to me, but then I have virtually no education in this area. Thanks! Bill ___ 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. ___ 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.
Re: [time-nuts] How does it work?
Thanks to all who responded. I should have been able to figure that out for myself... On Tue, Jun 28, 2011 at 1:15 PM, Jean-Louis Oneto jean-louis.on...@obs-azur.fr wrote: Hello, Roughly, the temperature can be seen as a measure of the brownian motion (ie shaking) of the atoms. So if you keep the atoms at rest, it's equivalent to cooling them. One definition of the absolute zero is that there is no motion of atoms. HTH, Jean-Louis - Original Message - From: William H. Fite omni...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, June 28, 2011 4:55 PM Subject: [time-nuts] How does it work? For the sake of this poor, befuddled non-engineer, would one of you worthy gentlemen explain how it is that lasers striking a mass of cesium atoms and compressing them into a ball (in a cesium fountain) has the effect of cooling them to near absolute zero? That seems counter-intuitive to me, but then I have virtually no education in this area. Thanks! Bill __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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.
Re: [time-nuts] How does it work?
A bit more on traps and LASER cooling: http://en.wikipedia.org/wiki/Laser_cooling BTW, optical frequency standards make H-MASERS look crummy. -John == For the sake of this poor, befuddled non-engineer, would one of you worthy gentlemen explain how it is that lasers striking a mass of cesium atoms and compressing them into a ball (in a cesium fountain) has the effect of cooling them to near absolute zero? That seems counter-intuitive to me, but then I have virtually no education in this area. Thanks! Bill ___ 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. ___ 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.
[time-nuts] 53132A counter slow frequency update
Hello, My new to me counter has a strange response when I change the input frequency. With the gate set to 1s, I can measure 100 MHz with plenty of digits. Then I change the frequency to 1 MHz and it takes several seconds to almost a minute for the display to change from 100 MHz to 1 MHz. The delay only occurs when I lower the input frequency quite a bit; 100 MHz to 10 MHz changes are displayed within 2 gate times. When I increase the frequency form 1 MHz to 100 MHz I always get the correct display after two gate times. This delay is proportional to the gate time; the updating is 10 times faster with 0.1 s gate time. Is this behavior typical for this counter? Thank you John Pease ___ 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.
Re: [time-nuts] 53132A counter slow frequency update
Do you have the autotrigger (or whatever it is called) engaged? That will slow things down if it is hunting for the zero crossing. Rick John Pease wrote: Hello, My new to me counter has a strange response when I change the input frequency. With the gate set to 1s, I can measure 100 MHz with plenty of digits. Then I change the frequency to 1 MHz and it takes several seconds to almost a minute for the display to change from 100 MHz to 1 MHz. The delay only occurs when I lower the input frequency quite a bit; 100 MHz to 10 MHz changes are displayed within 2 gate times. When I increase the frequency form 1 MHz to 100 MHz I always get the correct display after two gate times. This delay is proportional to the gate time; the updating is 10 times faster with 0.1 s gate time. Is this behavior typical for this counter? Thank you John Pease ___ 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. ___ 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.
Re: [time-nuts] Fwd: BIPM Annual Report on Time Activities 2010
Thanks for sharing the link On Tue, Jun 28, 2011 at 9:34 AM, Peter Vince pvi...@theiet.org wrote: The following report just released by the BIPM may be of interest. It includes a section detailing all standard frequency and time broadcasts. -- Forwarded message -- Dear Colleague, The BIPM Annual Report on Time Activities containing the information for 2010 is now available on the BIPM website at http://www.bipm.org/en/scientific/tai/time_ar2010.html Best regards, Hawai Konate BIPM Time Department ___ 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. ___ 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.
[time-nuts] Electronic hardware supplies
All, By this fall, I intend on opening an online business supplying electronic hardware, so to speak. I know most on here do a lot of home brewing circuits, and what I intend to sell is things to make this possible. I will be selling turret terminals, eyelets, FR4 unplated board, Micarda, IC adapter boards, square pad boards, and anything similar to what's known as Manhatten Construction type board products. I am also looking at stocking different hardware to go with them. I'm looking at the old prototyping ways, such as using eyelet and turret terminal boards for quick construction, and the tools for it. What I'm hoping for, is that if any on here could e-mail me, at my e-mail listed below, and let me know what you may be looking for in these types of supplies, or what you wish someone would stock. I will indeed look into it, and may include them if there is enough call for it. Right now, I am in the process of buying up stock for this fall, so now is the time to let me know. Thanks for any help on this. Send e-mails to: xfor...@citynet.net Thanks, Will Matney ___ 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.
Re: [time-nuts] TEC party file format?
I'm planning on counting 60Hz line cycles with some embedded hardware, then dumping the count over RS-232 every minute or so to a linux box running ntp. Any thoughts on what data to log? Scott, You have a PC and RS232? Skip the embedded hardware. An easy trick is to convert the 60 Hz sinewave into a narrow pulse and send it to -- a serial port. Someone else on the list can propose the minimum circuit for this (one 555 would do it, but there is probably a simpler way). If you make the pulse about 500 microseconds wide and configure the serial port for 9600 baud, then each pulse will be magically interpreted as a start bit (and some arbitrary data bits). Each 60 Hz cycle becomes one 500 us pulse becomes one RS232 binary byte becomes one read(). Note if the pulse is too short (100 us at 9600 baud) the port may miss it. If the pulse is too long (900 us) the byte may have a framing error. But anything in between is fine. Thus simply reading the serial port and counting the bytes, or hi-res timing the arrival of each byte, will give you the raw measurement that you need. From that you calculate things like period, frequency, accumulated time error, average frequency, etc. So the PC itself becomes your frequency counter, with NTP providing the long-term timebase stability you need. Mains cycles-per-second become RS232 bytes-per-second. You will get, on average, 60 bytes per second. At the end of a perfect day you would have read 5184000 characters. In Europe, it's 432 (50 Hz * 86400). The file format I use is mjd,te. mjd = modified julian date, and te = time error (the cumulative phase error, in seconds). For detailed study I log data once a cycle or once a second; for long-term monitoring and pretty plots, once a minute is more than enough. /tvb ___ 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.
Re: [time-nuts] TEC party file format?
On Tue, Jun 28, 2011 at 11:31 AM, Tom Van Baak t...@leapsecond.com wrote: I'm planning on counting 60Hz line cycles with some embedded hardware, then dumping the count over RS-232 every minute or so to a linux box running ntp. Any thoughts on what data to log? Scott, You have a PC and RS232? Skip the embedded hardware. An easy trick is to convert the 60 Hz sinewave into a narrow pulse and send it to -- a serial port. Someone else on the list can propose the minimum circuit for this (one 555 would do it, but there is probably a simpler way). If you make the pulse about 500 microseconds wide and configure the serial port for 9600 baud, then each pulse will be magically interpreted as a start bit (and some arbitrary data bits). Each 60 Hz cycle becomes one 500 us pulse You can do even better. Connect the pulse to pin one (DTR?) This is the same pin used for the PPS from a GPS unit. The Linux (or BSD) kernel will time pulses on this pin with a nanosecond resolution counter. On most computers that have a real hardware rs232 port you get accuracy way better then the microsecond level. The pulse will cause an interrupt and there is a kernel level device drivers that simply reads the clock and stores it. Then you need a user level program that polls the interface for data. When it sees data available it reads and gets the clock value. It will find data available 60 times per second. If you care about calibration to UTC then connect the pulse per second (pps) output from a GPS to a second port. The the PPS lets you calibrate the rate of the nanosecond counter and find the phase of the 60Hz signal relative to the UTC second The good part is that the data rates are low. 60Hz is dead slow for a modern computer. -- Chris Albertson Redondo Beach, California ___ 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.
Re: [time-nuts] TEC party file format?
Coming into this late so I have a very basic question. What level if resolution is required? Are variations in the line frequency expected to be at the 1% level or is this parts per million?Can we measure the frequency by averaging many cycles or are we looking for transients where the frequency jumps? Chris, The NERC is not really talking about changing frequency. I mean, it will still be 60 +/- 0.05, or whatever. The proposal is about eliminating the time error correction (TEC). This is a more gradual process, a steering of sorts. Ok, I know time and frequency are related, but the point is what you really want to monitor is the time error, that is the accumulated phase drift. Especially over days and weeks. In a case like this recording time error and then calculating frequency, or average frequency, is likely better than trying to make a bunch of periodic frequency measurements and then stitching them all together to guess the accumulated time. Around here the mains time drifts by a couple of seconds over the coarse of a day. Because of TEC it tends to head back to zero, on average. Note that a couple of seconds is a couple hundred cycles. So it's trivial to monitor this if you just count cycles and compare then to a reference. The reference should be accurate to better than 1ppm. /tvb ___ 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.
Re: [time-nuts] TEC party file format?
You can do even better. Connect the pulse to pin one (DTR?) This is the same pin used for the PPS from a GPS unit. The Linux (or BSD) ... Chris, Then the next step is to use an NTP driver that treats the 60 Hz pulses on DTR as the local time/frequency reference. Your PC will then run on mains time instead of UTC. Not sure how low a stratum that would be. Still, if you did this, then your existing NTP tools will give you all the logging and plots you need. Your PC is running mains; the rest of the network is UTC, so any time drift plots for your server will neatly indicate if TEC is working, or not. /tvb ___ 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.
Re: [time-nuts] 53132A counter slow frequency update
Do you have the autotrigger (or whatever it is called) engaged? That will slow things down if it is hunting for the zero crossing. Rick Hi Rick, I turned that off and used a manually set threshold, but it didn't matter. Some additional information: Firmware version 3646. When I change the frequency from 100 MHz to 1 MHz I can press the run button to get an immediate update of the displayed frequency otherwise there is a long delay as I described. John ___ 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.
Re: [time-nuts] TEC party file format?
Then the next step is to use an NTP driver that treats the 60 Hz pulses on DTR as the local time/frequency reference. Your PC will then run on mains time instead of UTC. Not sure how low a stratum that would be. Still, if you did this, then your existing NTP tools will give you all the logging and plots you need. Your PC is running mains; the rest of the network is UTC, so any time drift plots for your server will neatly indicate if TEC is working, or not. I don't think any of the current drivers in NTP will do the right thing for this project. The PPS driver is a bit tricky. It needs help to figure out which second a pulse corresponds to. I think there is a filter in there to reject samples that are too far off from what it thinks is a second boundary. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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.
Re: [time-nuts] Electronic hardware supplies
IMO, hams are a much bigger market than time-nuts. Also the Test Equipment guys. Here are some groups you might want to join: Tekscopes2 HP_Agilent_Equipment TestEquipTrader ArmyRadios All on YahooGroups MilSurplus ARC5 Boatanchors All on mailman.qth.net There are loads more ham groups. FWIW, -John All, By this fall, I intend on opening an online business supplying electronic hardware, so to speak. I know most on here do a lot of home brewing circuits, and what I intend to sell is things to make this possible. I will be selling turret terminals, eyelets, FR4 unplated board, Micarda, IC adapter boards, square pad boards, and anything similar to what's known as Manhatten Construction type board products. I am also looking at stocking different hardware to go with them. I'm looking at the old prototyping ways, such as using eyelet and turret terminal boards for quick construction, and the tools for it. What I'm hoping for, is that if any on here could e-mail me, at my e-mail listed below, and let me know what you may be looking for in these types of supplies, or what you wish someone would stock. I will indeed look into it, and may include them if there is enough call for it. Right now, I am in the process of buying up stock for this fall, so now is the time to let me know. Thanks for any help on this. Send e-mails to: xfor...@citynet.net Thanks, Will Matney ___ 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. ___ 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.
Re: [time-nuts] TEC party file format?
I don't think any of the current drivers in NTP will do the right thing for this project. The PPS driver is a bit tricky. It needs help to figure out which second a pulse corresponds to. I think there is a filter in there to reject samples that are too far off from what it thinks is a second boundary. Yeah, I didn't check the list of NTP drivers to see if one had been written already, or if an existing one could be made to work with a few lines of code. How does NTP handle the cases where an accurate 1PPS is available but the time itself isn't? This would be the case for most cesium or OCXO references, or maybe even some GPS 1PPS references. One could also use an external divide-by-60 counter to convert 60 Hz to 1 Hz - DCD. You could get clever and send 60 Hz to Rx as described earlier and 1 Hz to DCD on the same, or another port, for use by the NTP PPS driver. Or, use a software divider: let the user program that's reading the 60 bytes/second pulse DTR once every 60 bytes, tie this to NTP's DCD pin and -- the PC is generating its own 1PPS. My thought was simply that since NTP is fairly well-known, it might make a nice demo to see a power-line-sync'ed PC run for a couple of weeks before the TEC experiment, and then during the TEC experiment. /tvb ___ 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.
Re: [time-nuts] TEC party file format?
So the PC itself becomes your frequency counter, with NTP providing the long-term timebase stability you need. Mains cycles-per-second become RS232 bytes-per-second. You will get, on average, 60 bytes per second. At the end of a perfect day you would have read 5184000 characters. In Europe, it's 432 (50 Hz * 86400). I see two interesting problems with this sort of approach. One is glitches on the line, either lightning/whatever causing extra counts, or dropouts causing missed cycles. Does anybody know how often this sort of stuff happens? Does anybody have scope pictures? The other would be glitches on the PC. I can easily keep a system running for a week or a month, but every now and then I need to move the power plug or I get the urge to play with some software and ... If I have a day of good data, then a break, then more good data, how long can the break be so that I can correctly guess the number of cycles that were missed? It depends upon how much the frequency changes. If I extrapolate forward from before the break and back from after, the lines will intersect. If I can estimate the error in the slope of those lines I can see what happens if I use the high/low error cases. One thing that might help get back in cycle sync would be to use a PIC/AVR rather than a 555. The idea is that it can do the first layer of data reduction, say divide by 100. That would roughly multiply the get-back-in-sync time by 100. (assuming not much noise) The PIC could also send out a RS-232 text message with the count in it, or modulate the pulse width, say double the width every 1 cycles. Mumble there are lots of opportunities. Another idea is that once you get the PIC debugged, you probably won't have to reboot it because you are messing with other software on the box. -- An alternative would be to feed the 60 Hz into the audio port on the PC. No need for the 555 or whatever. The crystal driving the audio ADC is another variable but I think that won't be a major problem. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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.
Re: [time-nuts] TEC party file format?
I see two interesting problems with this sort of approach. One is glitches on the line, either lightning/whatever causing extra counts, or dropouts causing missed cycles. Does anybody know how often this sort of stuff happens? Does anybody have scope pictures? The beauty of time-stamping each cycle (each byte) is that you have a lot of data to work with to identify and correct short-term glitches like this. Normal frequency counters are at the mercy of glitches, but continuous time-stamping counters can, if they want, apply heuristics to a CW sequence and easily pinpoint cycles that are missing or doubly counted. If course if you are missing minutes of data it may be impossible to know for sure if you're off by a cycle or two. But to isolate bad data over the span of a few seconds, it's easy. The other would be glitches on the PC. I can easily keep a system running for a week or a month, but every now and then I need to move the power plug or I get the urge to play with some software and ... Correct. Then again, all you have to do is split the 60 Hz pulse train to two serial ports on different PC's. Serial ports are easy that way. The PIC could also send out a RS-232 text message with the count in it, or modulate the pulse width, say double the width every 1 cycles. Mumble there are lots of opportunities. See the start of these TEC thread(s). I'm collecting all my data with a PIC: 60 Hz in, RS232 time-stamps out. I can send one to you if you want to try it. An alternative would be to feed the 60 Hz into the audio port on the PC. No need for the 555 or whatever. The crystal driving the audio ADC is another variable but I think that won't be a major problem. Yeah, this was mentioned earlier. It turns out the crystal isn't a problem since all you're doing is counting 16 ms cycles within the realtime waveform capture buffer. In this case the ADC isn't used as much for edge timing as it is for edge counting. The sample rate or rate stability can be very low. /tvb ___ 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.
Re: [time-nuts] 60 Hz measurement party
On 06/25/2011 09:34 PM, Tom Van Baak wrote: We are more a group of experimenters than lamenters, so here's an open invitation to all of you in the US to join me on a 60 Hz measurement party, starting as soon as you can and lasting as many weeks or months that it takes to get interesting plots. Here is what I have used with far better success than transformers. For some reason the transformers I get hold of have quite large phase error (ie. they are cheap and get warm). http://wap.taur.dk/zcd/sch.jpg http://wap.taur.dk/zcd/plug.jpg Cp has the dual role of killing RF, and compensating for the H-L threshold of the HC14. It sits on the hot side, and charges up through the protection diodes for the next 200us pulse. It will drive 10m of POF. Substitute an opto coupler of choice if you need less isolation. /Kasper Pedersen ___ 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.
Re: [time-nuts] 60 Hz measurement party
Hi Kasper, Your picture shows what looks like a battery, but I do not see that included on the schematic ? This seems overly complicated seeing as how there are opto-couplers designed for this purpose. They even have Schmitt trigger functions incorporated. All in a 8 pin dip style package designed to provide separation and protection. BillWB6BNQ Kasper Pedersen wrote: On 06/25/2011 09:34 PM, Tom Van Baak wrote: We are more a group of experimenters than lamenters, so here's an open invitation to all of you in the US to join me on a 60 Hz measurement party, starting as soon as you can and lasting as many weeks or months that it takes to get interesting plots. Here is what I have used with far better success than transformers. For some reason the transformers I get hold of have quite large phase error (ie. they are cheap and get warm). http://wap.taur.dk/zcd/sch.jpg http://wap.taur.dk/zcd/plug.jpg Cp has the dual role of killing RF, and compensating for the H-L threshold of the HC14. It sits on the hot side, and charges up through the protection diodes for the next 200us pulse. It will drive 10m of POF. Substitute an opto coupler of choice if you need less isolation. /Kasper Pedersen ___ 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. ___ 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.
Re: [time-nuts] TEC party file format?
How does NTP handle the cases where an accurate 1PPS is available but the time itself isn't? This would be the case for most cesium or OCXO references, or maybe even some GPS 1PPS references. You need to get the rough time from some other source, say the network or from GPS via the serial port. I thought the PPS driver would ignore input pulses that are not close enough (say 125ms or 250ms) but I can't find it in a quick scan of the code so maybe I'm imagining things. Note that a Cesium or OCXO will drift. Even if the drift isn't a problem, you have to get their PPS lined up with the second ticks. GPSDOs are good. :) [You can also measure the offset. NTP can work with that.] Or, use a software divider: let the user program that's reading the 60 bytes/ second pulse DTR once every 60 bytes, tie this to NTP's DCD pin and -- the PC is generating its own 1PPS. There is a shared memory driver that lets you do something like that without any hardware. Look at the gpsd sources if you want to see how to feed it. For things like this, ntpd has a noselect option for a server or refclock. It collects all the data but doesn't use it, just puts it in log files. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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.
Re: [time-nuts] TEC party file format?
The Linux or BSD pulse per second interface is general enough to work for this. It does not care if the pulses are one per second or 100 per second, or 60. Al it does it capture a timmer/counter when a pulse comes in. Then fets a flag a user program can read that says data available. The user level programs reads the device ad gets the captured counter value, the flag is reset. Very simple and very low overhead. I think the counter units are nanoseconds On Tue, Jun 28, 2011 at 1:28 PM, Hal Murray hmur...@megapathdsl.net wrote: Then the next step is to use an NTP driver that treats the 60 Hz pulses on DTR as the local time/frequency reference. Your PC will then run on mains time instead of UTC. Not sure how low a stratum that would be. Still, if you did this, then your existing NTP tools will give you all the logging and plots you need. Your PC is running mains; the rest of the network is UTC, so any time drift plots for your server will neatly indicate if TEC is working, or not. I don't think any of the current drivers in NTP will do the right thing for this project. The PPS driver is a bit tricky. It needs help to figure out which second a pulse corresponds to. I think there is a filter in there to reject samples that are too far off from what it thinks is a second boundary. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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. -- Chris Albertson Redondo Beach, California ___ 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.
Re: [time-nuts] TEC party file format?
If I have a day of good data, then a break, then more good data, how long can the break be so that I can correctly guess the number of cycles that were missed? It depends upon how much the frequency changes. If I extrapolate forward from before the break and back from after, the lines will intersect. If I can estimate the error in the slope of those lines I can see what happens if I use the high/low error cases. Hal, Your logic sounds correct. Note the question of how accurately you can predict the future time or frequency of a clock, based on a long record of its past behavior, is exactly what the ADEV family of statistics give you. It's all about how much or little the frequency changes over time. I'll send you mains data from yesterday if you want to play with simulating missing data algorithms. I think in this case TDEV or MTIE is the statistic you want. I had to deal with this issue of data breaks in my relativity clock experiment on Mt Rainier (www.leapsecond.com/great2005, for new people on the list). In this case you have stable clocks and because of time dilation they slip cycles so to speak while you are away from home. The question is: how stable a clock do you need to have before you are sure you can see relativistic time dilation and not just nanoseconds of normal clock drift. One thing that might help get back in cycle sync would be to use a PIC/AVR rather than a 555. The idea is that it can do the first layer of data reduction, say divide by 100. That would roughly multiply the get-back-in-sync time by 100. (assuming not much noise) Correct. Or divide to get 1 pulse per minute, or hour, etc. You may laugh but even dividing by 5184000 (one pulse per day) would still give you enough points to make a really nice plot of US mains power timekeeping performance over a year. This illustrates the issue that for some cases (such as this one) occasionally recording time error (phase) is often easier and more reliable than making many uninterrupted frequency measurements and integrating them all to estimate net time error. /tvb ___ 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.
Re: [time-nuts] TEC party file format?
The Linux or BSD pulse per second interface is general enough to work for this. It does not care if the pulses are one per second or 100 per second, or 60. Al it does it capture a timmer/counter when a pulse comes in. Then fets a flag a user program can read that says data available. The user level programs reads the device ad gets the captured counter value, the flag is reset. Very simple and very low overhead. I think the counter units are nanoseconds There are two separate fields. One is the time stamp of the last tick, the other is a counter of the number of events since the device was created. That's exactly what we want for this application. You can write a simple loop: sleep a while, grab data, log stuff where stuff includes the raw data and the deltas from the last sample. (That info is duplicated for rising and falling edges.) -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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.
