100+ year digital watch? - Page 1
Forum section: electronics / projects

author: msuffidy
author_rank: Frequent Contributor
timestamp: January 22, 2025, 02:24:42 am
content: My friend and I were going on about automatic watches. I was saying the mechanics of automatic watches would fail. I was thinking the bast thing would be a digital watch with a solar panel and a super cap. Do you think that would work with some basic exposure to light and last like a whole lifetime? Obviously you would be looking for the lowest power display and logic.

author: edpalmer42
author_rank: Super Contributor
timestamp: January 22, 2025, 03:34:24 am
content: There are lots of solar powered quartz watches. I have six Citizen Eco-Drive analog quartz watches. They have a solar cell that recharges a Lithium battery. In total darkness they will run for something like 6 - 8 months depending on the model. They tried supercaps but they can't store enough power to be practical. The battery won't last for a century, but they do say that it has a 40 year design life and after 20 years it retains 80% of its capacity.I have one watch that includes a perpetual calendar. It knows the date, month, and what year of the leap year cycle it's in. As long as you keep the battery charged, you only have to adjust the time every few months. There are other models that are rated for 10 sec. per year accuracy. Other models sync from GPS or stations like WWVB.Seiko and Casio also have solar powered watches - analog, digital, and mixed. I suspect that other brands exist. Just search ebay or amazon for ' solar powered watch '.

author: Smokey
author_rank: Super Contributor
timestamp: January 22, 2025, 04:01:13 am
content: How big of a battery would you be willing to wear on your wrist to have a 100-year-without-recharge watch is really the question. Of course it's possible, but maybe not stylish.

author: SteveThackery
author_rank: Super Contributor
timestamp: January 22, 2025, 10:14:47 am
content: 100 years is not that difficult for a mechanical watch, provided it is adequately jewelled. I have several, still original, even going back to the 19th century. The only issue is with the lubricants: they eventually fail, at which point the watch needs a strip, clean, and relube.Strictly speaking, the "only" above isn't quite right. Older mechanical watches used spring steel mainsprings, which were prone to breaking. The problem was fixed decades ago so modern mechanical watches don't have that problem. Most old mechanical watches will have been retrofitted with an "unbreakable" mainspring by now.So, I would say a mechanical watch would be a very strong candidate indeed for a hundred year watch.

author: watchmaker
author_rank: Unknown
timestamp: January 22, 2025, 11:57:51 am
content: Quote from: msuffidy on January 22, 2025, 02:24:42 amYes, if your hypothetical digital watch and mechanical automatic watch were never serviced, the mechanical watch would likely fail first (but not because it is automatic).But Steve is correct. In 1900 Hamilton was mass producing railroad watches with specs that beat modern Rolex specs, and the Rolex use automatic to keep even torque on the escapement which reduces issues related to achieving those specs.These 125 year old railroad watches can still be serviced back to original specs (6 seconds per day difference across 6 positions) which is better than Rolex of 10 seconds per day.Here is a link you may find interesting:https://www.historictimekeepers.com/documents/Watch%20Adjustment.pdf

author: Haenk
author_rank: Super Contributor
timestamp: January 22, 2025, 12:42:06 pm
content: Quote from: watchmaker on January 22, 2025, 11:57:51 amI'm no watch expert, but I remember hearing about requiring a certain maximum deviation to receive a certificate. Quick google search: COSC.Even Rolex builds to a price, and certainly *could* do better specs, but that increases the price and slows production. Not sure if there is a market for a "twice as accurate, but twice the price"-watch. With the high frequency quartz watches, there already is a semi-mechanical solution if you require precision. Or go digital with atomic clock receiver built in.

author: watchmaker
author_rank: Unknown
timestamp: January 22, 2025, 01:05:10 pm
content: There is a point that I call trivial precision. Given watches today are simply jewelry and there are more precise and cheap ways to determine time, modern COSC specifications are more than sufficient.However, there was a day (not all that long ago) when air and sea navigation required precise mechanical timekeepers and railroads required crews to be at certain locations at a specific time to avoid collisions. Not to mention physicists and astronomers.I thank the gods for the crazy people who think a mass produced tourbillon is worth $350K. They add nothing of value ever since the development of the alloy balance spring (elasticity does not vary with with temp; 1922 Nobel prize) and the use of autowind to maintain constant torque. CAD/CAM etc.It was one thing when a tourbillon was made by one individual; it was a marque of craftsmanship. Today that legacy is exploited.But at least those buyers keep the industry afloat.OTOH, making watches that kept the difference in rate across positions to under 10 seconds per day (and some Hamilton calibers wer adjusted to under 6 seconds per day) in an era that predates electronic timing machines and even modern statistical methods is a feat to be marveled at.AS and aside, years ago Girard Perragaux was faced with a crisis regarding final timing of their watches. There were two women who did all this work. They were twins and about to retire. Oops!You cannot apply the context of today's manufacturing techniques to those of 50 years ago let alone 125 years ago. Those achievements should not be taken for granted.

author: SteveThackery
author_rank: Super Contributor
timestamp: January 22, 2025, 04:09:22 pm
content: Quote from: Haenk on January 22, 2025, 12:42:06 pmInterestingly, the OP didn't specify the required accuracy, nor whether servicing the watch is allowed. If perfect accuracy is a requirement, the watch would need to receive NTP, a radio time standard, or GPS. No doable with a mechanical watch. 😁Finally, the OP did mention "digital watch" in the title. Although unusual, there are plenty of mechanical watches with digital displays, so they are still in the running.

author: SteveThackery
author_rank: Super Contributor
timestamp: January 22, 2025, 04:13:10 pm
content: Quote from: Haenk on January 22, 2025, 12:42:06 pmWhat do you mean,@Haenk? Semi-mechanical??

author: GLouie
author_rank: Regular Contributor
timestamp: January 22, 2025, 05:56:03 pm
content: Perhaps to add more fuel to the fire, IMO the digital-solar-NIST watch may seem like it would do, but there is no guarantee of continued time satellites, and more importantly, I sincerely doubt a digital watch would last a century.My guess is the electronics would fail from tin whiskers, corrosion, adhesives age, etc. as would any plastics well before 100 years. I'd put my money on an all-metal mechanical/auto watch, but again, we don't know if service is allowed or accuracy needed.

author: Haenk
author_rank: Super Contributor
timestamp: January 23, 2025, 09:12:17 am
content: Quote from: SteveThackery on January 22, 2025, 04:13:10 pmAnalog quartz watches are semi-mechanical - you have all the gearing of an analog watch, but an electrical drive train (instead of a wind-up spring). So that would make the worst possible combination of two worlds, as you have two technologies that like to fail (battery & mechanics).The high frequency quartz watch I was talking about is this one:https://www.omegawatches.com/de-de/chronicle/1974-the-most-accurate-wristwatch-ever(The are other models available, and I think other manufacturers later used the same idea.)

author: Siwastaja
author_rank: Super Contributor
timestamp: January 23, 2025, 09:26:16 am
content: Supercapacitor (which is an electrolytic capacitor) lifetime will be a likely problem. They age.

author: voltsandjolts
author_rank: Unknown
timestamp: January 23, 2025, 10:25:28 am
content: Sounds like a use case for a diamond battery, if you really needed a watch to last that long, or longer.

author: watchmaker
author_rank: Unknown
timestamp: January 23, 2025, 10:32:09 am
content: Quote from: Siwastaja on January 23, 2025, 09:26:16 amThat was one of the biggest jokes in the trade. They still had to replaced in less than five years and the cost was much higher than 3 battery changes.Watchmaking has had its fair share of gimmicks. The Omega Coaxial is another notable example (yes, I was trained on it by Omega). It took several market iterations to get it right and I am not sure it is yet without its quirks (I retired about 8 years ago). The design as executed by Daniels works well but was not suited to mass production.Like the tourbillion, it was once a marque of mastery, now just an expensive toy.Dirty little secret, with a few notable exceptions, virtually all of the autowind chronos since 1995 use the same movement made by Swatch (7750). This applies to most of the microbrands as well. And the fact is, any watch past a Rolex does not offer a meaningful improvement in timekeeping. It is all about autowind and the alloy balance spring.Oh, BTW, for our exams, we had to bring stock Eta 2892s to precision time. All 12 got it to under 3 seconds per day rate difference in8positions, not the standard 3. As noted above, it is all about the balance spring and autowind.While used car dealers and drug cartels gave Rolex a bad name (cartels actually used Rolex watches to launder money, buying high in cash (grey market distributors) and selling at slight loss), I spent several months training on Rolex and they are a watchmaker's watch. Meant to be taken down and reassembled with ease, like a Swiss machine tool.What many do not remember, is that prior to the quartz crisis, Omega were the premier watch and Rolex was the second. But, during that crisis, Rolex stuck to mechanical while Omega went to less expensive mechanicals and quartz which cost it prestige.All in my family have late 1960 Omega Constellations. I know the person who designed the 751/752 caliber and it holds a place in my heart. But today, either buy a vintage Omega that has not been "improved" or a new Rolex (if you can find one). Far too many vintage Rolex have been "upgraded" for me to recommend those out of hand. My daughter has her eye on my 1967 Speedmaster.FWIW, I no longer even wear a watch. Ironic.

author: AndyC_772
author_rank: Super Contributor
timestamp: January 23, 2025, 11:04:46 am
content: Quote from: Haenk on January 23, 2025, 09:12:17 amI like the Seiko Spring Drive movement. It uses a quartz crystal and a tiny microchip to regulate time, but power comes from a wound mainspring. As this unwinds it spins a wheel called the 'glide wheel' which generates electricity to power the chip. The chip measures how fast it's spinning with reference to the crystal and applies an electromagnetic brake to regulate its speed precisely, and the hands are driven via a simple gear train.The end result is a movement which is completely smooth, with no ticking at all. There's no battery to go flat or fail, and even as the mechanism wears it still keeps good time, right up to the point where it simply cannot turn any more.

author: Haenk
author_rank: Super Contributor
timestamp: January 23, 2025, 11:37:32 am
content: Quote from: watchmaker on January 23, 2025, 10:32:09 amFunny; I stopped wearing a watch as a student more than 30 years ago - and never went back. Still have about two dozen of watches, and my first watch (Seiko) from 40 years ago. Purchased on a holiday trip to GB. As a kid, I *had* to have this watch with a running man

author: SteveThackery
author_rank: Super Contributor
timestamp: January 23, 2025, 02:55:02 pm
content: Quote from: Haenk on January 23, 2025, 09:12:17 amAh, I can see you're not a watchmaker. Firstly, saying mechanics "like to fail" isn't entirely true. Also, it depends on how you define "fail". Does lubricant failure count as a mechanical fail? I can see the argument both ways: it's not the mechanism itself that fails, nor does it need repair, but the watch has still stopped. I don't think "like to fail" is true of the better quality watches. As I said earlier, I have watches going back to the 1890s with movements in top condition. Not all, but definitely some. Typically you get some well known wear or failure points in certain movements, basically due to design shortcomings or unsuitable materials. These movements get a reputation for trouble. But they are a minority, I would say; there are many movements that just seem to go on forever.Secondly, and crucially, there is an enormous difference between the gear train in a fully mechanical watch and a quartz watch. The mechanical watch gear train is under considerable torque all the time, so steps to reduce wear are required, and some mechanical watches do suffer from significant wear. The gear train in a quartz watch is under virtually zero torque, so wear is basically a non-issue. Therefore it isn't true to say that a quartz analogue watch is the "worst of all worlds"; the gear train has an exceptionally low wear rate and failure rate. I've got quartz analogue watches going back to the 1970s, and every single one of them has a pristine mechanism.We haven't discussed the importance of the case to both mechanical and electronic watches. Ingress of water and dust is probably the number one failure mechanism for most watches, especially as the dust contaminates the lubricant. In fact, I might even stick my neck out and say a really good case is more important than a really good mechanism. Debatable, yes, but it has some merit.Interestingly, I've found watch electronics to be remarkably durable and reliable. I think in 45 years I've only replaced two electronic modules (although I haven't done anything like the volume@watchmakerhas).The reliability and durability of watches is a complicated subject, but some of mine have already beaten the OP's challenge.

author: SteveThackery
author_rank: Super Contributor
timestamp: January 23, 2025, 03:11:29 pm
content: Quote from: watchmaker on January 23, 2025, 10:32:09 amGoodness me, yes. That was one of Seiko's biggest blunders in its history. Their first "self-winding" quartz range was called "AGS" (automatic generating system) and it was a disaster. The retailer I bought mine from sold five, and he told me he'd had three of them back for a refund. The energy recovery was totally inadequate, requiring the wearer to be practically hyperactive. And the energy storage was dire: just a few days from fully charged. And to add insult to injury the lifespan of the supercaps was little better than normal watch batteries.Seiko went quiet for a while and the AGS disappeared from all the retailers I checked out. After a year or so a new range appeared called "Kinetic", which was much better, not least because it used a rechargeable battery instead of a supercapacitor. The energy recovery seemed more effective, too. However, even to this day the number one failure mode for Kinetic watches is the rechargeable battery.

author: AndyC_772
author_rank: Super Contributor
timestamp: January 23, 2025, 04:30:50 pm
content: Fortunately they're easy to replace and parts are readily available.I have a titanium Kinetic that my wife bought me about 25 years ago. It's had a couple of new batteries in that time, but that's it. Still works perfectly, and keeps running even though I rarely wear it for more than an hour or so at a time.

author: Terry Bites
author_rank: Super Contributor
timestamp: January 23, 2025, 06:00:09 pm
content: Beer talk.......