Unique handmade digital LED clocks

[digitalledclock]

If you are looking for something very modern and unique this is the place www.digitalledclock.com

[richard_uk]

Would be nice if the advert stated a price :wink:

[rewolf]

nice, indeed, but "frequency stability is +/- 100PPM." +/-8.6 sec per day or 4:20 min per month - really?
my grandmothers's 106 year old wall clock is better than that (true!)

[digitalledclock]

the price is 220 cad + transport

regarding frequency stability this is the answer from Fox Electronics:

?100ppm refers to the drift of frequency across the stated temperature
range.
( -10+60, 0to+70, -20+70, -40+85 )
That means that a device with a stability of ?100ppm, would be within
100 hertz per million of the design frequency. A 25MHz device will
never be more than (25 x 100) 2,500 Hertz either higher or lower than the
25,000,000 Hertz design at any temperature inside the guarantee.

From -40 to +85C, never less than 24,997,500Hz and never more than
25,002,500Hz.
It will usually be much closer, but it is guaranteed never to exceed
100 parts for every million of design.

So it will not affect the time in a year very much, unless it is the
same temperature all the time.
Compared to the total seconds in a year. That 100ppm would be
100seconds out of each million of a year would be an equivalent of 3,150
seconds of drift in a year. It is just not the same type of thing. The
oscillator drift increases and decreases with temperature and 1 month, 1
year, or 5 years doesn't make any difference. Maybe after the 5 years,
the 15ppm deviation you saw at first has become 20ppm.

[bruce wegmann]

That still doesn't sound very good against Pulsar's stated 2 [yes, two] parts per million stability to achieve their 60sec/year guaranteed timekeeping accuracy [and this was in the 70s; surely things should have improved a great deal in 30 years!]. I keep batteries in all my working watches [140 and counting], and I can tell you from direct observation that most of them are still within that 60 second range, and a fair number better than that [my original Date/Command, bought in 1974, ran 21 seconds slow last year, or 0.67ppm; my Hamilton MIB2, made in 2002, came in at 13 sec, or 0.44ppm]. I think you would be better off to derive your timing signals from the line frequency [AC power actually sells you a time standard, as well as electricity; the number of cycles-per-second is adjusted so that, at the end of the day, exactly 60 [or 50, as the case may be] x 60 x 60 x 24 cycles have been generated, and over even a years' time, will show almost no deviation. I have an LED clock that I built in 1975, that has been in continuous use for 31 years, and it is always dead-on for the correct time [and for those wondering, the LEDs are just as bright now as they were when I first fired it up, so I tend to believe that LEDs are, in fact, very long-lived devices].
And for those of you who think I have too much spare time on my hands to make such notes, you're right, but I have learned to live with it.

[retroleds]

Haing purchased a lot of new crystals, my first thought seeing the 100 ppm drift was - huh, they could have just spent a a few cents more and got much better numbers. The ones I typically get are +/-20ppm over -20c to +80c, with 3ppm total aging . :? Less than a buck.

I liked seeing Bruce talking about the powere company sending out it's 60 hz cycle...my old man was telling me about that when I was really young. Only time it gets badly off is during heavy usage periods and then the power company picks up the pace(usuaully at night) to even things out. All our plug-n analog clocks have used that pulse,reliably, for years. The Sunbeam clock I grabbed from my old man's house still keeps flawless time in my barn. 8)

[collector]

I'll leave all of the real "techie' stuff to all of experts here - all I know is that my Jungans Atomic / Radio controlled watches are always accurate to the second each and every day. I use these to set my other watches / vintage clocks.

As far as watch accuracy, I collect different technology watches (and like Bruce track their accuracy). My favorite 14K GF Pulsar P2 looses 3 seconds every month. My other Pulsars are not as accurate, they wander between 15 - 55 seconds per month (the Pulsar Sport 3502 is the worst actor). My Bulova Sideview wanders 2 - 3 minutes per month even though it is truly NOS. The Spaceview Accutrons are much better, none wander more than 3-10 seconds per month. My Seiko Kinetics are basically all bad actors, all wander several minutes per month.

On another note, my wife and I also collect OLD 1900 - 1940 mechanical clocks (windup and electric). Some are better than others, 2 minutes to 15 minutes per month. The Westinghouse windup from 1920 looses only 2 minutes per month - not bad for a 86 year old clock!! It keeps better time than the Sideview and all of the Kinetcs - so much for "Newer" technology!!!!

It would be interesting to hear from others on their "Accuracy" experiences!!!

[CompuChron2]

I work for Air France , and accuracy is a very important point , so there are radio controlled wall clock everywhere in the place.

But from one angle I can see 2 wall clocks (radio controlled) at the same time and I can see there is ALWAYS one minute difference between this 2!

Maybe they are too far from a window to be really radio controlled?

[Synchroserious]

Same goes for cell phones.When I put 2 phones (same brand) next to each other and charging there is always a 58 second difference in the 2.
Also in a trip to NY back in march 2005 I answeed the phone up there and spoke with a Synchronar owner who had a few questions about setting a MK IV,which is very simple and then asked why the watch had lost 10-15 seconds in one day.I then asked what he was using for a time reference and he told me his cellphone.So I informed him that the cellphone had gained the 10-15 seconds.He called back the next day and confirmed what I told him was true.He lives in NYC and perhaps the tall buildings have an effect on how often an update signal is received.

[collector]

The time source I use to verify time on my watches is:

http://www.time.gov/timezone.cgi?Eastern/d/-5/java

This is the official US government site for time.

From what I understand, this site is also the sync source for all Atomic/Radio/NETWORK controlled devices is the US.

If a "RADIO CONTROLLED" watch/clock/device is off by as much as 1 second something is wrong with that individual device. I personally now have three Junghans "Atomic" watches and all sync automatically to this site perfectly - all have the exact time to the second.

As far as the problem synchroserious has pointed out, I am not sure of how that sequence of events is happening as I do not know of a cell phone that displays seconds. Additionally, the time on the cell phone display should be accurate to the minute as the telco's use Stratum Clocks whice are synced to the time source/site I mentioned previously. As a verification experiment, I timed my 4, 2 Sprint 2 Nextel, cell phones against this site and all timed perfectly to the minute change in Denver. (Yes, I do have 4 individual personal cellphones.) Sprint and Nextel have seperate networks here in the states so they do use different devices but they all do track back to the central time source. So it would be interesting to hear more of his story.

FYI - if one DIALS into a "telephone company TIME RECORDING" here in the US chances are that you will hear the wrong time. As an example, if I dial into the phone company site at 11:59AM my Junghans AND the time.gov site are all 7 seconds slow, if I dial in exactly 2 minutes later at 12:01PM the same watches and site are now 7 seconds fast. This happens every day so obviously the telco's voice announcement system is off a little bit.

As an aside, wouldn't it be nice to have a "Atomic"Radio controlled" LED watch? Yeah I know dream on, as right now seconds are even a big problem!!!

[Synchroserious]

The cell phones (Nokia) like collector says have no seconds.I just know that they are only on the same minute for a guess of 2 seconds.Also the 10-15 seconds was just off the top and the gentlmen may have said 6 or 8 seconds.Strangly enough the customers first name is Hamilton and some may know him from a different forum.
The US Navy atomic clocks, I think 3 or 4, all vary slightly from each other so they take the overall avg reading of them and I think the clock in Boulder Colorado to determine the accuracy of a guided missile.If the timing is off by 1/1000 or less of a second it is the difference on hitting a village of innocent civilians or the intended target. Wether this missille activity is right or wrong or is intended for the right reasons is for someone else to decide and a different subject.Since we are talking about time I just thought of mentioning one of the most critical momments when even fragments of a second matter.Hope to hear some more interesting time talk from others,meanwhile I am going back to the workbench.

[retroleds]

I agree on cell phones showing different time - my wife and I are on the same network, the same bill, with the same brand of phone(different models), and we had noticed at some point that hers would usually read 20-33 seconds ahead of mine. I would understand it if she and I were several miles apart - then different cell towers would be handling our calls, but this is while we have the phones side by side. :?

Both of the atomic clocks I own get "goofy" every few months. Timing gets off by several hours, the clocks get confused on our location and have to be totally reset. I REally like self-sufficient timepieces like LEDs, amoungst others. 8)

[collector]

Hi Ed,

Agree on the LED self sufficient requirement, but, what source do you use to set them / check their accuracy???

[Fitron]

hmm the most accurate clock is my house is my late great granny's mantlepiece clock which is nigh on 100 years old,but then again I've spent long enough adjusting the pendulum to get it that way - oh and it's got a magnificently mellow bong on the half hour and hour, but there's no way I can wear it on my wrist.

Has anyone checked out the Ceefax* clock for accruacy as that's my normal setter ?

* Ceefax is the BBC tv information service in the UK that is accessable through a remote control.

[retroleds]

Hi Ed,

Agree on the LED self sufficient requirement, but, what source do you use to set them / check their accuracy???

I am not so concerned about absolute accuracy - I think we really want timepieces to give us a frame of reference against our own perception of time passing...so, why quibble over a few seconds every so often? Look at the cell phone: it stops telling time within 3-4 days of being away from it's charger; it will often show grossly incorrect time or no time if away from it's signal towers; and, requires as much or more effort to check the time on as in checking an LED wristwatch. And so much of the population thinks that is a better way to have "the time" available? I'm thinking that even a watch that misses "real time" by 2 minutes a month is better than not having a clue what time it is, sometimes. Plus, I just like hitting the button on an LED - it's strangly conforting to know my watch's heart is beating away. But that's just me. :wink:

[CompuChron2]

I agree , what I love in wearing Led watch is seeing the red numbers lighting ; I often have to check twice by the way:the first time I think waouh , the red leds are crips and bright , what a nice watch I have but I have to push the button another time because I didn't the time!


Talking accuracy , did you know that the faster you go , the slower the time passes by (therory of relativity):
You take the 2 more accurate clocks on earth(atomic) , you put one in your living room , the second one you put it in F16 plane that goes mach 2.2 for 2 hours , you come back in your living room and compare the time after the flight , the one in your living room will be ahead by a few 1/100000 of a sec...

There is no exact time!

[richard_uk]

you lot really need to get out more! :D

[Fitron]

Get out more ? I spent some quality time in the cupboard under the stairs on Saturday with my bulova N4. What's wrong with that? :)