Watches lovers

[RJSV]

   Miti:
   Is it possible to bypass the lack of explicit formula, (at least in the short term),  by coming up with ways to measure the lift angle, like perhaps a high speed video recorder.
   I understand that might not be any easier, but at least you could identify any barriers to doing things empirically.

Anyway, wanted to make sure you know that the thread here is appreciated and read with enjoyment!
   One doctor this month had a feature filled watch he was using, (checking pulse).  Next time, I want to ask about his interest in all things mechanical time!

[edpalmer42]

Has anyone dug into the bowels of the Citizen Eco-Drive watches?

If you're not familiar with them, they're quartz watches with a solar cell to charge an internal rechargeable lithium battery.  The battery is designed to last for at least 10, maybe 20 years.

I recently picked one up on an impulse for the princely sum of C$25.  "Needs a new battery."  No, the battery just needed charging - a process that takes days if the battery is completely flat.  That process is underway and seems to be going well.  The voltage of the MT621 battery is ~1V4 as compared to a nominal 1V5.  The problem is that this watch also has a 'Power Reserve' dial that shows the state of charge of the battery.  So far, it hasn't moved.  There's no tech info online to explain exactly how this thing is supposed to work - i.e. something like 0% = 1V4, 50% = 1V45, 100% = 1V5.  All I found is info stating that there were problems with the feature.

Has anyone experimented with these things?  Is 1V4 not enough voltage for them to react?  Is there a simple fix?  I'm considering removing the battery, which is trivial to do, and externally charging it but I'm holding off on that until I see what voltage the solar cell manages to charge to.  Apparently the open circuit voltage from the solar cell is ~1V8.

FYI, I've attached one of the auction pictures.  Yes, there are scratches on the crystal.

Ed

[Miti]

No, I didn't leave this thread but… life - work “balance”, pun intended.

   Miti:
   Is it possible to bypass the lack of explicit formula, (at least in the short term),  by coming up with ways to measure the lift angle, like perhaps a high speed video recorder.

There are different methods to find the lift angle, the one where I apply a known stimulus and see if the timegrapher measures correctly could be one.

Has anyone dug into the bowels of the Citizen Eco-Drive watches?

If you're not familiar with them, they're quartz watches with a solar cell to charge an internal rechargeable lithium battery.  The battery is designed to last for at least 10, maybe 20 years.

I have one, my wife has two. Citizen has warehouse sales twice a year and we bought at relatively good price.
Is it Lithium or supercap? I read somewhere that it is supercap. I never opened one but… now that you mentioned. 😁

[watchmaker]

   Miti:
   Is it possible to bypass the lack of explicit formula, (at least in the short term),  by coming up with ways to measure the lift angle, like perhaps a high speed video recorder.
   I understand that might not be any easier, but at least you could identify any barriers to doing things empirically.

Anyway, wanted to make sure you know that the thread here is appreciated and read with enjoyment!
   One doctor this month had a feature filled watch he was using, (checking pulse).  Next time, I want to ask about his interest in all things mechanical time!

With the exception of the Omega Coaxial, virtually all modern watches (since 1970) have a nominal lift angle of 52 degrees.  Hamilton pocket wathces use 48 degrees and other pocket watches can go down to 42 degrees.

However, the lift angle for a specific movement can be +- 2 degrees different from nominal.  This is because of adjustments needed to "match the escapement" which means ensuring the escapement works as efficiently as possible.
 
Here is a link to an article (that is too large) which describes the process (with photos) for adjusting the escapement for precision timing.

historictimekeepers.com/documents/Watch Adjustment.pdf

[Gyro]

...
I have one, my wife has two. Citizen has warehouse sales twice a year and we bought at relatively good price.
Is it Lithium or supercap? I read somewhere that it is supercap. I never opened one but… now that you mentioned. 😁

Likewise, we both have one.

Irrc, Citizen Eco-Drive use a Lithium-titanate (LTO) cell rather than a supercap. So do Seiko Kinetic watches. They have high charge-discharge cycle life and good operating temperature range*. I think the Eco-Drive uses an LED in a basic overcharge protection circuit.

I've read of several examples of these cells not recovering from deep discharge, including a thread on here somewhere, so it's important to pull out the crown to the second stop if you are putting them in storage. This matches my own experience too, where my old, stored in the dark, Eco-Drive watch won't come out of low battery indication no matter how much sunlight it gets. Luckily the cell is replaceable.


Edit: * ...and fast charge acceptance, important if you want to get the most out of occasional glimpses of strong sunlight.

[edpalmer42]

Has anyone dug into the bowels of the Citizen Eco-Drive watches?

If you're not familiar with them, they're quartz watches with a solar cell to charge an internal rechargeable lithium battery.  The battery is designed to last for at least 10, maybe 20 years.

I have one, my wife has two. Citizen has warehouse sales twice a year and we bought at relatively good price.
Is it Lithium or supercap? I read somewhere that it is supercap. I never opened one but… now that you mentioned. 😁

Sorry for the late reply.  Somehow I missed these messages.

I've read that the first Eco-Drive watches used supercaps, but they quickly realized that supercaps just didn't have enough capacity to be practical so they switched to rechargeable batteries.  But I think the marketing types still want to refer to it as a capacitor so that they can claim that there are no batteries to replace.

Ed

[edpalmer42]

Irrc, Citizen Eco-Drive use a Lithium-titanate (LTO) cell rather than a supercap. So do Seiko Kinetic watches. They have high charge-discharge cycle life and good operating temperature range*. I think the Eco-Drive uses an LED in a basic overcharge protection circuit.

I've read of several examples of these cells not recovering from deep discharge, including a thread on here somewhere, so it's important to pull out the crown to the second stop if you are putting them in storage. This matches my own experience too, where my old, stored in the dark, Eco-Drive watch won't come out of low battery indication no matter how much sunlight it gets. Luckily the cell is replaceable.

Edit: * ...and fast charge acceptance, important if you want to get the most out of occasional glimpses of strong sunlight.

If they use an LED, I've never seen it.  I read a report from a user that the open-circuit voltage from the solar cell is ~1V8.  That's well within the safe charge voltage - actually, it's a bit low - so I wondered if that was their 'overcharge protection'.  I've also seen one Technical Information document that show battery voltage of up to 2V6 so that couldn't be an LED.

I've only worked on two Eco-Drive watches, but they both had a test point for the battery's negative terminal.  It's marked (-) .  I've used this to track the charge state of the battery during my testing.  Once the voltage reaches ~1V65 it starts to climb rapidly.  I've considered that to mean that the battery is fully charged.

My light source is a high-intensity LED desk lamp.  The head of the lamp is shaped like a spotlight that happens to be 40 mm in diameter.  My light meter says that when the head is about 25 mm from the meter the light intensity matches the midday sun.  Since the lamp is above the watch, any heat it does generate rises away from the watch.  You'd think the lamp was designed for charging solar watches!

Ed

[Zucca]

https://www.sensorwatch.net/

I have one and I it will probably be my last watch purchase. Very very happy.

[TimFox]

Two unrelated comments relevant to mechanical watches.
1.  Developers of high-resolution x-ray imagers, where time was also important, found pocket watches to be ideal test objects.  A good high-speed imager could resolve the fine internal components even though the guts were oscillating.  Apparently, European and American mechanical watches use different standard oscillation frequencies, and pocket watches tend to be slower than wristwatches.
2.  My mechanical watch is a Russian "Mikhail Moskvin" manual-wind watch, 17 jewels, with a transparent back, good to 3 Atm.
I purchased it in Uglich, during a tour in 2018, after the factory had closed a few years before.  I'm not sure if this is really an older Soviet make, or a recent re-branding of foreign movements.

[Gyro]

Irrc, Citizen Eco-Drive use a Lithium-titanate (LTO) cell rather than a supercap. So do Seiko Kinetic watches. They have high charge-discharge cycle life and good operating temperature range*. I think the Eco-Drive uses an LED in a basic overcharge protection circuit.

I've read of several examples of these cells not recovering from deep discharge, including a thread on here somewhere, so it's important to pull out the crown to the second stop if you are putting them in storage. This matches my own experience too, where my old, stored in the dark, Eco-Drive watch won't come out of low battery indication no matter how much sunlight it gets. Luckily the cell is replaceable.

Edit: * ...and fast charge acceptance, important if you want to get the most out of occasional glimpses of strong sunlight.

If they use an LED, I've never seen it.  I read a report from a user that the open-circuit voltage from the solar cell is ~1V8.  That's well within the safe charge voltage - actually, it's a bit low - so I wondered if that was their 'overcharge protection'.  I've also seen one Technical Information document that show battery voltage of up to 2V6 so that couldn't be an LED.

I've only worked on two Eco-Drive watches, but they both had a test point for the battery's negative terminal.  It's marked (-) .  I've used this to track the charge state of the battery during my testing.  Once the voltage reaches ~1V65 it starts to climb rapidly.  I've considered that to mean that the battery is fully charged.

My light source is a high-intensity LED desk lamp.  The head of the lamp is shaped like a spotlight that happens to be 40 mm in diameter.  My light meter says that when the head is about 25 mm from the meter the light intensity matches the midday sun.  Since the lamp is above the watch, any heat it does generate rises away from the watch.  You'd think the lamp was designed for charging solar watches!

Ed

I can't remember where I read about the LED (maybe that was an early implementation too), but the movement information does indicate that there is an overcharge protection circuit... https://www.citizenwatch.co.uk/media/calibres/E031/E031_ebook.pdf

[jimdeane]

I'll go ahead and reply here, since I want to track the thread.

I'm interested in watches in general, and have a small collection.

[SteveThackery]

I've been repairing clocks and watches for 45 years, although only briefly as my main source of income. Around 20 years ago I served as Chairman at the British Horological Institute for a couple of years, and led the rewrite of their Distance Learning Course (DLC) just after that. I've had three papers (I think) published in the Horological Science Newsletter (an NAWCC publication) .

I use a homebrew timing machine where most of the processing is done in software on a PC. It provides Fourier analysis of the rate as a way of identifying train faults. The input is a homebrew watch microphone, and a slotted optocoupler for monitoring pendulums. I've experimented with various other input devices, including proximity detectors, et al.

I have a collection of 60-odd wristwatches, all of which are "affordable" - I'm not interested in paying stupid money for the privilege of being ripped off by the Swiss.  Most of my watches have some small thing that makes them interesting, and actually that includes a couple of watches that are so battered they've clearly spent decades on the wrists of workmen or labourers providing faithful service. Others include tuning fork watches, electrically impulsed balances, very early quartz technology, unusual time readout, and so on.

I despise the Swiss watch industry - they sell middle-of-the-road technology for outrageous amounts of money, and leading-edge technology for prices well above that of a brand new luxury home in a two-acre plot. For a bloody wristwatch! Then they ensure all servicing and repair can only be done by themselves by refusing to make parts available. Basically the whole industry is a racket, and - apart from the very top of the range - it's not like their watches are anything special at all.

Now, whenever anyone asks me for a recommendation on what watch to buy, I always say Japanese. Seiko and Citizen between them make a fine range of mechanical and quartz watches, and unlike the Swiss, prices are reasonable, parts are available, and quality is proportionate to price.

[Miti]

I despise the Swiss watch industry - they sell middle-of-the-road technology for outrageous amounts of money, and leading-edge technology for prices well above that of a brand new luxury home in a two-acre plot. For a bloody wristwatch! Then they ensure all servicing and repair can only be done by themselves by refusing to make parts available. Basically the whole industry is a racket, and - apart from the very top of the range - it's not like their watches are anything special at all.

Now, whenever anyone asks me for a recommendation on what watch to buy, I always say Japanese. Seiko and Citizen between them make a fine range of mechanical and quartz watches, and unlike the Swiss, prices are reasonable, parts are available, and quality is proportionate to price.

I totally agree. Great minds think alike… 

[RoGeorge]

Is anybody here into watches? I repair and restore them and I would like to exchange some info sometimes.

I reverse engineered one once, does this counts as being into watches? 

Got an electronic wrist watch that can detected the heart beat by sensing the bio-electric currents with a chest-belt sensor.  The chest-belt detector sends the BPM value (Beats Per Minute heart rate) by radio (110kHz on/off modulation), to be displayed on the wrist watch's display.

Wanted to decode the radio signals, so I could receive the BPM values with another receiver then log the BPM and plot that for an entire day.  For this, made a heart emulator, then improvised a receiver, then made a fake transmitter, then put a webcam to watch the watch display, then a vision program to snapshot the BPM from the wrist-watch display, like this:













https://rogeorge.wordpress.com/2016/08/13/the-wireless-protocol-of-a-sports-wrist-watch/
https://rogeorge.wordpress.com/2017/02/16/the-wireless-protocol-of-a-sports-wrist-watch-part-2/
https://rogeorge.wordpress.com/2017/03/29/the-wireless-protocol-of-a-sports-wrist-watch-part-3/
(sorry for the shameless plug)

[EEVblog]

[Miti]

I reverse engineered one once, does this counts as being into watches? 

I don't see why not. Thanks for posting! Interesting project!

Cheers,
Miti

[Miti]

Thanks Dave!
Yes indeed the date is not really usable (read visible) on these analog watches, specially after a certain age. Even glasses don't seem to help much anymore. Plus the need to adjust it after every month with 31 (or 28, 29) days.

Cheers,
Miti

[edpalmer42]

Thanks Dave!
Yes indeed the date is not really usable (read visible) on these analog watches, specially after a certain age. Even glasses don't seem to help much anymore. Plus the need to adjust it after every month with 31 (or 28, 29) days.

Cheers,
Miti

I've been considering getting one of the Eco-Drive watches with a perpetual calendar.  Of course, that's trivial for a digital or radio-controlled watch, but it's more interesting for a stand-alone analog quartz model.  Add on a HAQ feature and you basically never have to change or adjust the watch.  Just keep it charged and it's good to go.  Of course, since I'm a cheap bottom-feeder it may never happen.

[Miti]

I finally found some time to fix my “Rolex “, the seconds hand was missing. I repaired it using a small piece from a syringe needle. Boy, was that invisible… I’ve lost it few times and found it again.
Anyway, doesn’t look bad. I’ve also extended my Kenneth Cole SS band using 3D printed PLA  .
KC service wanted for two links more than I paid for the watch.
It’s not invisible, hardly noticeable but functional.

[Bryn]

I like watches myself, although I'm currently investing in one that would give me accurate time without me having to set it anytime my watch is like four minutes slow. I guess the solution to that would be a smartwatch which I wouldn't mind transitioning too, unless there's a digital watch that can do the same.

Might rummage through Amazon regarding something like that later in the week...

[Miti]

I like watches myself, although I'm currently investing in one that would give me accurate time without me having to set it anytime my watch is like four minutes slow. I guess the solution to that would be a smartwatch which I wouldn't mind transitioning too, unless there's a digital watch that can do the same.

Might rummage through Amazon regarding something like that later in the week...

I’m ok with setting it every now and then instead of charging it every day. No smart watch for me. That’s one of the reasons why I really like my Timex Ironman Datalink. The battery lasts for years but it has semi smart functions.

[SteveThackery]

I've read that the first Eco-Drive watches used supercaps, but they quickly realized that supercaps just didn't have enough capacity to be practical so they switched to rechargeable batteries.  But I think the marketing types still want to refer to it as a capacitor so that they can claim that there are no batteries to replace.
Ed

I can tell you for sure that the original Seiko Kinetic - actually called the AGS (automatic generating system) - used a supercap, and it was an unmitigated disaster. Firstly, the energy recovery from body movement was crap - you had to be far more active than a wearer of a mechanical automatic. Secondly, the run time was only a few days.

Seiko painted themselves into a tight little corner with these. According to my jeweler, he had to return three out of every five he sold due to the inadequate energy harvesting. Here in the UK at least, the AGS disappeared from the shelves for a good three years.

All AGS and Kinetics have a power reserve indication, and here was a delicious conundrum. The voltage of the capacitor was proportional to the charge in it, so it was electronically simple to make a linear conversion from cap voltage to power reserve.

With the launch of the Kinetic, Seiko abandoned supercaps and went to a rechargeable cell. The UK service manager told me they had developed a tweak to the chemistry to make the voltage drop off more proportionately with charge - the exact opposite of what most battery manufacturers try to achieve.  This was to allow a basic voltage sense circuit to provide the power reserve readout.

At last it worked - sort of.  The power reserve indication was still a bit rubbish, showing fully charged until almost empty. Seiko refined this functionality over the following years. However, they had a problem with all the original AGS watches still in use. The supercaps went out of production so Seiko had to supply replacement rechargeable batteries to the trade, which were physically almost identical to the previous supercaps and dropped straight in with no tweak other than a change of insulator.

But the AGS was designed to use supercaps, and was launched before the decision to fit batteries. As such the power reserve indication was rendered unusable: it expected a nice linear voltage drop from 1.5V to tell it the charge level, but in reality the battery voltage changed far less. An AGS with a supercaps gave a reasonable indication of charge, with a run time of several days. An AGS with battery would have a power reserve in months, indicating "full" for all but the final week or two.

Basically the whole story is one of failure and compromise.

Interestingly, Seiko and Citizen both chose supercaps genuinely never expecting them to need changing. The thought was that a quartz watch is the lightest of light duty, and yet for reasons I don't understand, all of the supercaps eventually failed. I thought they would have lasted essentially forever unless their voltage or current ratings are exceeded.

[themadhippy]

Timex Ironman Datalink. The battery lasts for years

Dont they just.  I  "lost" mine, a couple of years later i was   sorting some little used camping  kit out ,next morning i heard an alarm going off, the watch was in the  packed  tent,battery still going strong even with the alarm going of daily for 2 or 3 years.

[edpalmer42]

I've read that the first Eco-Drive watches used supercaps, but they quickly realized that supercaps just didn't have enough capacity to be practical so they switched to rechargeable batteries.  But I think the marketing types still want to refer to it as a capacitor so that they can claim that there are no batteries to replace.
Ed

At last it worked - sort of.  The power reserve indication was still a bit rubbish, showing fully charged until almost empty. Seiko refined this functionality over the following years. However, they had a problem with all the original AGS watches still in use. The supercaps went out of production so Seiko had to supply replacement rechargeable batteries to the trade, which were physically almost identical to the previous supercaps and dropped straight in with no tweak other than a change of insulator.

But the AGS was designed to use supercaps, and was launched before the decision to fit batteries. As such the power reserve indication was rendered unusable: it expected a nice linear voltage drop from 1.5V to tell it the charge level, but in reality the battery voltage changed far less. An AGS with a supercaps gave a reasonable indication of charge, with a run time of several days. An AGS with battery would have a power reserve in months, indicating "full" for all but the final week or two.

Well, the PRI on my Eco-drive (pictured earlier in this thread) is very non-linear.  When it steps from Zone 3 (highest charge) to Zone 2, you're probably at the 50% level and things get even more compressed further down.  But I don't think that detracts from the feature's usefulness at all.  There's no inherent value in having a linear scale for this application.  Just having a 4-step indicator is very useful.

[SteveThackery]

Well, the PRI on my Eco-drive (pictured earlier in this thread) is very non-linear.  When it steps from Zone 3 (highest charge) to Zone 2, you're probably at the 50% level and things get even more compressed further down.  But I don't think that detracts from the feature's usefulness at all.  There's no inherent value in having a linear scale for this application.  Just having a 4-step indicator is very useful.

Indeed. It's just not what Seiko intended.

Personally I think a linear indication is much better. I wouldn't want my car's petrol gauge to be seriously non-linear.