Atomic watch - Page 1
Forum section: electronics / general

author: dexters_lab
author_rank: Unknown
timestamp: May 01, 2013, 10:39:09 pm
content: Saw this on el reg in the uk, its a pocket watch movement with a caesium based oscillator within, thought it might be of interest. I guess you have to ask why but hey its kind cool.I wonder if the wonky and missing leds are deliberate (in 2nd pic)?http://www.theregister.co.uk/2013/05/01/hoptroff_shows_first_atomic_watch_movement/

author: c4757p
author_rank: Super Contributor
timestamp: May 01, 2013, 10:48:47 pm
content: God I hate people sometimes.QuoteSo... there's none of whatever he calls "craftsmanship" (engineering plus whiny nostalgia) in making a cesium clock the size of a watch? Useless twit...

author: ve7xen
author_rank: Super Contributor
timestamp: May 01, 2013, 10:53:43 pm
content: Saw this on time-nuts earlier. 120mW power consumption... You'll be lucky to get a couple of hours out of it on the size of LiPo cell you'd want to have in a watch. Probably less. Kinda defeats the purpose of ultra stability when you've got to maintain the thing more often than any instability would be visible.Silly. But what hack isn't.

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: May 02, 2013, 02:06:22 am
content: It's about timeYou won't wonder what you need it for once my time travel machine is complete, a few seconds in a thousand years adds up.

author: ecat
author_rank: Frequent Contributor
timestamp: May 02, 2013, 04:05:54 am
content: Quote from: 4to20Milliamps on May 02, 2013, 02:06:22 amHa!!!I bet my time travel machine is completed before yours :p

author: codeboy2k
author_rank: Super Contributor
timestamp: May 02, 2013, 04:38:13 am
content: I'm more interested in the atomic clockI can see this device, theQuantum SA.45s, being an available option in high end gear from test equipment manufacturers, instead of an OCXOor perhaps they will *still* use an OCXO on the devices because it's cheaper and good enough for most users, but produce a reference standard with this cesium clock in it so that a small lab can afford to sync their equipment to something very accurate.

author: zibadun
author_rank: Regular Contributor
timestamp: May 02, 2013, 05:03:35 am
content: Actually, the atomic wristwatch has been around for a whilehttp://leapsecond.com/pages/atomic-bill/This page is at least five years old

author: amyk
author_rank: Super Contributor
timestamp: May 02, 2013, 11:27:12 am
content: Quote from: codeboy2k on May 02, 2013, 04:38:13 amApparently the SA.45s costs $1500... which isn't all that much more than a rubidium reference.

author: gxti
author_rank: Frequent Contributor
timestamp: May 02, 2013, 12:41:12 pm
content: CSAC pretty much is a rubidium standard. It actually uses cesium, but not in the way a cesium beam tube does -- it's more similar to a typical Rb standard, except even simpler as it does not require microwave excitation.More info on how it works here:http://tf.nist.gov/ofm/smallclock/CPT_clocks.htmlThe stated performance is also comparable to typical Rb standards, but since test gear has few constraints on size or power a Rb standard would get the job done more cheaply. I could see it being an option in gear that otherwise could only accommodate an OCXO though, perhaps for military applications where having the standard as a separate unit might not be feasible.

author: jpb
author_rank: Super Contributor
timestamp: October 03, 2013, 08:38:56 am
content: This one seems to be a proper atomic watch - but not cheap or very small!http://www.theregister.co.uk/2013/10/03/highend_chrono_chaps_build_atomic_watch/

author: ElectroIrradiator
author_rank: Frequent Contributor
timestamp: October 03, 2013, 09:40:45 am
content: Quote from: c4757p on May 01, 2013, 10:48:47 pmFrom the perspective of a high end mechanical wrist watch, then really no, there isn't.The final assembly and adjustment of a wristwatch sizedtourbillon, or many similar contraptions inside mechanical watches, cannot in any way, shape or form be automated nor done assembly line fashion by unskilled labor.Even when starting with micro-CNC fabricated parts made to the highest possible precision, it still takes severaldaysworth of actual adjustment and tweaking time by a skilled watchmaker to assemble and calibrate a*reliably running*tourbillon. Actual calendar time used is much longer than that, as each 'tweak' frequently needs one or more prolonged test periods, before the next assembly step can commence.Even getting the training and experience needed to be able to do the job at all takes many years of watchmaker experience, potentially decades even. So the job cannot be outsourced to cheap, low skilled workers in a third world country.I am not aware of anything in any atomic clock, which requires the same level of skill on part of the people fabricating them?Conversely, you could make a killing in the world of luxury watches, if you know how to build a machine, which can automate tourbillon assembly/calibration and many similar processes.----Edit: Added emphasis to 'reliably running', as that is the key here.

author: G7PSK
author_rank: Super Contributor
timestamp: October 03, 2013, 10:47:29 am
content: When I was training as a watchmaker the proper name of which is Horologist, it was emphasised frequently that if a watch or clock was made as accurately as a cars gearbox it would/could not work and conversely if a cars gearbox was made to the same standards as a watch the gears would either not mesh at all or bind such that the gearbox would not work, the skill is in getting the watches cogs to mesh with the least loss in energy as well as all the pivots,staffs and balances adjusted so that the watch will run let alone keep time.

author: c4757p
author_rank: Super Contributor
timestamp: October 03, 2013, 10:53:02 am
content: The skill is moved from the fabricators to the designers. It's still there, though. Why do people care at which part in the process the "skill" is introduced?

author: ElectroIrradiator
author_rank: Frequent Contributor
timestamp: October 03, 2013, 11:57:08 am
content: Quote from: c4757p on October 03, 2013, 10:53:02 amBecause expensive items, which cannot be mass produced, carries a high social status. Same thing as the hand painted pin stripe you can have put on your new Rolls Royce, or the hand crafted leather interior. You wont ever see either in your average Toyota grocery getter.In addition to possibly a ring, then a wrist watch is in many circles the only kind of jewelry a man can wear without social stigma. Which is one reason why some people put a lot of emphasis on their choice of watch.

author: sub
author_rank: Regular Contributor
timestamp: October 03, 2013, 12:06:21 pm
content: Quote from: codeboy2k on May 02, 2013, 04:38:13 amOCXOs outperform Rubidium/Caesium standards over shorter time periods. Atomic standards are only good for long-term stability; in the short term they are noisier than quartz. If the CSAC works its way into frequency counters and the like, it will be as the reference oscillator for an OCXO-based PLL, which is necessary to clean up the relatively noisy output from the atomic clock.

author: Dave
author_rank: Super Contributor
timestamp: October 03, 2013, 01:10:32 pm
content: Quote from: ElectroIrradiator on October 03, 2013, 11:57:08 amCufflinks and belt.