It' here!

[jdexter]

Salutations:

My synchronar arrived today and am I think I am very pleased.

I am looking at some interesting ways into the case at the moment and noted that mine (a black back) has a what appears to be some sort of sealed hole on the side opposite the LED face - the rear of the watch if you will.

I note it is the same side as would have been used to adjust with a magnet where it a Mark I and it does have some sort of black plug in the middle.

As to power, can anyone here tell me what the farrad rating of the two factory batteries would have been?

Also - can anyone reliably tell me if the case should be stainless or chromed white metal? It does have a magnet shot at the rear, but I am not sure that is helpful.

Cheers and best wishes and thanks in advance.

Jon

[charger105]

Hi jdexter.
The hole you are talking about is where the potting gel was injected I believe.
I'm not sure I understand what you're after with the 'farrad rating' requirement. Each battery was originally 50mAh if that helps.

I believe most of the cases were SS, but I think i did read somewhere that they did experiment with chromed base metal at some stage. There were also solid gold, gold plated, black ceramic and titanium.

Just found this post, which outlines case types:
http://www.dwf.nu/viewtopic.php?p=16575 ... 27bf8b34b9

Rgds,
Andrew.

[charger105]

Hi jdexter.
The hole you are talking about is where the potting gel was injected I believe.
I'm not sure I understand what you're after with the 'farrad rating' requirement. Each battery was originally 50mAh if that helps.

I believe most of the cases were SS, but I think i did read somewhere that they did experiment with chromed base metal at some stage. There were also solid gold, gold plated, black ceramic and titanium.

Just found this post, which outlines case types:
http://www.dwf.nu/viewtopic.php?p=16575 ... 27bf8b34b9

Rgds,
Andrew.

[jdexter]

Good to meet you Andrew - thanks for the insight on the plug. I am trying to understand as much as possible about the watch and while this board is a godsend in that regard - it is sometimes hard to pick out the info between the sometimes heated debates.

I am interested in farrad ratings given some ideas around power conversion I'm exploring - supplier units of measurement are farrad rather than than mAh and I'm not having much luck finding a conversion tool.

My serial number appears to be 39992, which I think makes it around 1980 - but would dearly love to hear from someone who knows. I want to try cleaning up the case and would hate find out it was plate once the wheel gets spinning.

Cheers and best wishes.

Jon

[Old Tom]

Farads would normally be used to rate the energy capacity of a capacitor and while there have been watches made that used capacitors as energy storage devices (older Seiko Kinetics and Citizen Eco) all Synchronars used batteries (nicads originally, Nickel Metal-Hydride lately and as replacements for nicads) which are usually rated in mAh as they are fixed voltage devices (so..... total capacity in Farads is fairly easy to calculate given voltage and the mAh figure, if you must!).

[retroleds]

Howard Reihl has been filling them with Varta 70s and 80 - correspondingly 70 & 80 mah. 50mah may be all they could fit in that size, back in the day. Don't fry a good board throwing a burst from a capacitor thru it. Maybe member ReWolf can give you some ideas on possibly safe usage.

[rewolf]

Theoretically, you will not damage anything by adding a DISCHARGED capacitor instead of a battery.

Danger arises when you start charging: a battery limits the voltage to its max charging voltage, even if you keep on charging after they are fully charged (with a low current like solar cells deliver). So 2 NiCds or NiMHs limit the max voltage to about 2.9V.
A capacitor does NOT limit the voltage (unless it breaks down dur to overvoltage..), so it will charge up to the max voltage the solar cells can deliver under "no load" condition (IIRC 0.45V per cell; how many cells does the Synchronar have?).

Anyway it will not work.
A capacitor's voltage decreases linearly with its remaining charge, whereas a battery delivers fairly constant voltage.
Example: battery and capacitor both charged to 2.8V = 100%
Battery discharged to 50%: 2.4V - watch still works
Capacitor at 50%: 1.4V - watch does not work.

Say the watch needs minimum 1.8V and the solar cell charges to max 3.0V (still safe for the movement, but most GoldCaps have their limit at 2.5V).
So you can only use 1.8/3.0 = 60% of the capacity, e.g. 0.6F of a 1.0F capacitor.

Now let's calculate the "Farads" of a 50mAh battery:
50mAh = 180C (=Coulomb) of charge; 1C = 1A x 1s
To get this with a capacitor by discharging it from 3.0 to 1.8V (1.2V) you'd need a capacity C = Q/U = 180Coulombs/1.2Volts = 150Farads !
Even if you could use the capacitors full charge (discharge down to 0V) you'd need 180C/3V = 60Farads

Say you have 2 Farad capacitor charged to 3.0V.
How long can it deliver 20mA (LEDs on) until voltage reaches 1.8V?
We have a charge of 2F x 1.2V = 2.4C
2.4C is 2.4As = 2400mAs -> T=2400mAs/20mA = 120 seconds until the lights go out

(I hope this wasn't too much detail)

[retroleds]

I knew ReWolf would be able to lay this all out for you. Good job!!

[Old Tom]

And a 150F capacitor would be about the size of three original Synchronar boxes glued together, judging by the 5F ones I have here!

[clockace]

hi, i think you should stick with the varta 80's. they will fit in the recesses in the black bottom perfectly. your main problem is going to be opening the module w/o destroying the wire bonded chip. the gel sticks to the lead wires and the slightest pull in the wrong way will pull them loose. i destroyed my sunwatch probably opening it. i have rebuilt 6 mkI/II's w/o a problem. the mkIII/IV is an entirely different animal. with the mkI/II's the main problem is replacing the cells and the qc. doing that is quite simple. once i did that they all lit up properly. i also had to replace the sc on 2 of them, also not difficult. you must be VERY careful opening yours. i went around the seam with a jewelers saw to the depth of the red top wall thickness. the i went around it again about .030" above the previous cut, creating a narrow strip of red top. then i used a small screwdriver blade to peel the strip out. once i did that the glue seal was pretty much broken and i was able to pry the top and bottom apart with a wider screwdriver blade. you must be VERY careful once the top and bottom begin to separate. allow the gel to break free under its own tension w/o stretching it too much. with care it can be done. if i do it again i will do it the same way, but be much more careful. peter

[jdexter]

WOW - thanks very much gents!

That is *a lot* of great info and very much appreciated. I think I am not the only one interested in this problem.

You are correct, I am looking into the latest generation of super caps - or - a regulated hybrid. Perhaps as a replacement for the base/bottom itself.

So, based on ReWolf's most excellent outline can anyone here tell me:

- What is the minimum operating voltage and max drain on the Synchronar?

- What the operational output of the Solar Cell is supposed to be and how/if it is regulated?

- What is the maximum power the board and IC are rated for?

- Has anyone ever tried a capacitor in test and if so, what were the results with what Cap(s) - how quickly did it charge and discharge in the system?

Regarding opening, I have partnered up with a very good jeweler in this regard - his advise mirrored yours with a twist. We were thinking about setting up a flat mill so that we can cut a perfect line around the seam and then use it to guide a jeweler's saw so it remains square.

Why did you need to cut a second line? Is the black bottom ledged?

Thanks again to everyone for this assistance - win, lose or draw - I intend to document this rebuild so that the detail is properly available. Also, we are looking at a local plastics shop that might be able to pull a short run of tops and bottoms for us if we don't destroy our original.

Cheers and best wishes.

[clockace]

not only is the black bottom ledged, i goes into the red top as far as the cells are thick. if you try to slice it off at the seam all you will accomplish is shaving off the plus sides of the cells. they are in recesses in the black bottom, placed diagonally as you can probably see when examining the bottom outside carefully. the part that is ledged sticks up inside the red top. it is also glued pretty much the whole depth of the ledge. that is why i made 2 cuts. i have already tried to open one by a cut along the seam. doesn't work. 2 cuts, 1 at the seam, one .030" above the 1st will leave a small strip of red top that can easily be removed with a small screwdriver. this will expose more of the ledge of the black bottom. you will see what i mean when you do it. you can try to open it however you like, but you may NOT like the results. if you break any of the leads on the wire bonded chip. you are dead in the water. when making your cuts across the face with the display you must be careful not to go too deep. i made only 1 cut at the seam on the display end. when you pry the top and bottom apart, the display end will probably crack loose by itself. the red top is very thin on that end. the gel will try to hold the 2 pieces together. pry slowly and carefully and the tension of the gel will release itself. the gel is very sticky. the gel covering the chip on the display end has to be left alone. do not try to remove it by picking at it. you WILL break the bonds. i have ruined 2 of these mk III/IV modules trying to open them. the 2nd method i used will probaby work if you are careful. if anyone else has a better method to open them, they have not posted it as far as i know. best wishes. peter

[jdexter]

Cool tip Clockace and I hope you didn't misunderstand my question - it wasn't meant as anything snarky. I really need the info I'm asking for.

If we are setting up a mill, would you think there was any advantage to cutting up at 45 degrees from the outside lower edge of the black back until it meets the inner ledge? Could you provide any measurements for the ledge depth and width?

I have been thinking about how to seperate the back from the gel as well and may have an answer for both of us. The trick may be to use a very fine hypodermic and carefully inject fluid between the lexan base and the potting gel once a seam is opened. This should push the gel away rather than pull it.

We have seen several small air pockets along the seam under x15 magnification and in theory, this suggests that the gel may have a skin where it meets the lexan.

Cheers and best wishes.

[clockace]

you should scan and check all previous posts on this subject. there is one from jan 29, 2008, by j. thomas that shows the inside of the sunwatch with the wire bonded chip. the photo is looking at it as if you had the red top down in your hand and lifted the black bottom off. the cells come out with the black bottom. they are tightly snapped in recesses in the black bottom. you need to note polarity and snip the wires to separate the bottom from the rest of the module. the pc, display, and entire assy will still be firmly stuck in the red top by the gel. i don't think injecting anything in there is a good idea. there will be a big glob of snotty gel over the chip. i noticed in the photo it has been removed, but i don't know how without ruining the wire bonds. those tiny wires are smaller than the hair on your head and made out of lead. the display also is wire bonded to segments, with snotty, sticky gel on it as well. if there is something to dissolve the gel by immersion that would probably be best. i made a saw cut into each corner of the red top most of the way thru and peeled the sides open. the pc and parts are easy to lift out after that. i did get signs of life out of it by replacing the cells, but only a few segments lit up. i then tried to replace the qc and never got anything after that. i traced 2.6v from the cells to the chip, but nothing out of the chip to the qc. that's when i started to remove the gel over the chip by picking at it. i am sure that is what killed it. but after a rather steep learning curve [and expensive] i now know what not to do. if you are going to use a mill i would still go in the way i did with 2 cuts. the ledge on the black bottom is about 4mm high so the glued part is pretty far in the red top. i was able to salvage the bottom, but you will need a new red top. they are all the same size. peter p/s, you can look into the module thru the corner where the qc and a resistor is. it has a cavity in that part of the black bottom for these parts.

[retroleds]

I'll add this on, some is only a slight modification of what Howard R. has suggested.

Re: Taking the whole assembly from the top.
The whole thing is stuck in there thru vacuum adhesion - a small hole or two in the top will let some air in. Warming the whole thing under a light bulb or hair dryer(Careful) will soften the gell and help it all slide out. The wire bonds on some models were coated with anything from acrylic nailpolish(what Howard uses, I don't recommend it due to shrinkage issue with solvent based products), to epoxies. Generally speaking you are out of luck on those wire bonds unless you can see the particular bond for a segment that is out and push thru the gel with a needle and get it back in contact. Doesn't mean it will stay there. Even the finest needle looks huge compared to a wire bond.

BTW: the solar cell is already covered with potting gel if potted correctly, so what's the worry if you want to try a hypo of something? But air would work just as well for a start.

Hi % alcohol will soften and remove the gel, but immersion of the parts is pretty scary. Many of your other board mounted components are going to be attacked by the alcohol and many of these pieces have traces on the boards that are flimsy to begin with. It's sort of like battery corrosion on any brand when it comes to the circuit - you can use an alkaline solution to remove the crystalized metal salts, but you might also remove the last little piece of metal making any contact. We've discussed battery corrosion on other brands, some say leave it, others say remove it. I'm generally in the latter.

Re. the batteries - has anyone else gone looking at what manufacturers say about not potting ni-cads? That they need to vent on a very small scale? It's a major point of contention between myself and Howard.

Black bottoms - I saw a single groove all the way around(jewelers saw_ and use a hot wire knife to chop thru the last piece at the corners. Either I gently pry out the remainder of the bottom from the top (goes easier as you go along, just keep pluckin at the edge with an Xacto fine tip razor) or I just leave it if the piece works off a battery change alone. Went thru this with a customer lately - his Synchronar worked perfectly with a battery change, so I refused to pull it out and swap case. I hate writing a "Dear John" letter after telling them the piece was working.

I'm thinking(don't get offended, just my opinion) the effort to make new tops and bottoms might not be an effective use of time - if the people who bought batches of parts could get together with the comparitively few people who have a working module, there are lots of cases to spare. I've been selling off some Synchronar parts myself as I figure out how many workers I have compared to the extra parts. Seems to be a 1 out of 5-7 recovery rate on the modules, which leaves a LOT of spare parts. And boxes. Unfortunately.

[rewolf]

....can anyone here tell me:

- What is the minimum operating voltage and max drain on the Synchronar?

-What the operational output of the Solar Cell is supposed to be and how/if it is regulated?

-What is the maximum power the board and IC are rated for?

-Has anyone ever tried a capacitor in test and if so, what were the results with what Cap(s) - how quickly did it charge and discharge in the system?

Minimum operating voltage: According to the Synchronar patent, the LEDs shut off below 2.1V, but the timekeeping circuit still keeps on working - don't know how deep down it goes, 1.8V perhaps. However, if you have a working Synchronar, you can try this out with an adjustible power supply.

Max drain: it depends heavily on the LED brightness level. I was told that the standard battery lasts 5-10h in medium mode and 1.5h in bright mode. With 50mAh usably capacity this would mean 5-10mA on medium and 30 in high. I'd assume 20mA for calculations. But again: easily measured.

Output of solar cell: good question, I have no idea. But it's quite easy to measure: expose solar cell to direct sunlight and measure output voltage without load, and then short-circuit current (just connect the ampère-meter to the terminals - it will not damage the cells). Probably 3.6V (8? cells with 0.45V each) resp. 5-10mA.
It is not regulated, just fed to the batteries via a diode. The patent shows a resistor in parallel with the solar cells (but doesn't mention its value), proably to reduce the open-circuit voltage of the solar cells under full sunlight.

Max power: don't know, 3V should be no problem. Again, according to the patent, the LED drivers are constant-current driven above 2.8V, so probably even 4.0V will still not damage anything.

Using a capacitor: I know that Howard Riehl wanted to try this, but not if he actually did.
How quickly it charges depends on the solar cells. A 2F capacitor constantly charged with 5mA will go from 1.8V to 3.0V in 8 minutes.
Discharge see previous posting.
You still need the standby current consumption. Assuming 5µA, the 2F capacitor will discharge from 3.0V to 1.8V in about 130h - and every second with LEDs on costs about 1h standby time.

Please keep in mind: all this is purely theoretical - I've never touched a Synchronar. I'd be happy to see someone prove or disprove these figures by actual measurements.

[charger105]

Thought I'd add my experiences ragrding opening a Synch module. I simply use a craft knife, and continually run it around the edge, abrading a miniscule amount of the red lexan. Eventually you can just gradually prise the top from the bottom. I've done this several times on MkIIIs MkIVs and MkIs. It saves you from destroying the top and the bottom. The space created by the small amount of lexan that gets removed, is taken up by whatever you use to seal the module back up. Mind you, I did slice my palm open once, so the method (or me) is not perfect !

The two resistors in parallel with the solar cell are for the brightness measurement. The voltage between the 2 resistors is indicative of the amount of light incident on the solar cell. This point is connected to the brightness leg of the IC. If the resistors are big enough, very little current is drawn down this path, so that maximum current is delivered to the batteries. This is in relation to the MkIs and IIs only. In MkIIIs and MkIVs, this is all integrated into the IC.

Regarding displays, encapsulated ones are the best to work with. You may be lucky. If it is exposed wire bonds, I believe each connection is double wire-bonded, with a varnish or something (as Ed said) coating. Howard reckons they're more robust than you'd think, and I agree with him. You can just "peel" the gel off the display in one go, with little chance of damage.

Rgds,
Andrew.

[jdexter]

Fantastic info gents, thank you very much for the insights.

Rewolf - I will report back with hard numbers once I get the egg cracked one way or the other. Thank you very much for your generous time and thoughts on this problem. As you may have surmised, I am wondering if there is enough of a window between 2V and 3/4V where the watch can replenish a new generation capacitor quickly enough in trade for the lack of storage. Basically, cycle the storage much more often.

As to the case, more so now, I am convinced that most MIII/IV modules are damaged whilst they are being opened for exactly the reasons and cautions outlined above. Clearly the wirebonds to the IC are meant to live in the potting gel itself - which is a pretty clever way to protect a wire bond circuit - like veins in a flesh.

The problem arises for us when we want to get to the batteries in that any lateral, compressive or pull force applied to the potting gel is going to be reflected across the whole gel mass. This is clearly dangerous given the chance of shearing the wirebonds in the gel.

I was not actually thinking we should try to remove the module from the upper case for the above reasons - rather - try to get an injected fluid to wick between the case back and the gel to release it with minimum shear and pressure to the gel body itself. I may have to rethink this based on everyone's very helpful advise here.

Perhaps the best thing to do (first pass) is to try to mill out the batteries as plugs individually from the back then use a basic silicone solvent to release them from the mass?

This assumes that a given synchronar that was worn (been cleaning out the dead skin from the case edges today) would not likely have failed for any other reason but battery exhaustion.

I've kicked these folks a request for materials compatibility:

http://www.dynaloy.com/

They have several nondestructive solvents for silicone and epoxy that may prove helpful to your challenge as well as mine. I'll report back with anything they send me.

Cheers and best wishes.

[Snetzka]

I have a few dimensional drawings that i put together for my own purposes, these outline the black base and the Sunwatch top (I am still trying to obtain a Synchronar top - any offers.?.) These drawings show clearly the ledge detail and dimensions, these were not for production purposes, but for my own peace of mind in knowing where things were located and hence depth of cut etc.. I am happy to share these if they are of any use. Whilst we are on this subject, i also produced a sketch with the dimensions for the solar cell with readings that i obtained from a few old and new cell's.. for O/C voltage and S/C current.

Is it possible for us as a group have a repository to put these documents for all to share..?? Then we have a single point reference source, rather than trolling back through the threads (Although some of it is great reading!). I am happy to share what documentation i have for the greater good as long as i am not going to tread on toes / upset people and it does not contravene any intellectual property.

Mike.

[retroleds]

If anyone wants to collect documents or drawings,etc. together, we can always make a sticki at the top of the Synchronar forum with links to the info....duplicated on www.ledwatches.net. I've knocked a few things off my regular schedule, so I am hoping I''ll make another burst of changes and additions to the sites and this forum during the winter months.

Thread above mentioned "silicone solvent". The potting gel isn't silicone ....I've never heard of a silicone solvent. They are generally impervious to most chemicals.

Drilling out the batteries is risky business - most of the Synchronars have the power wires criss-crossing and/or diving between other components, so I'm thinking that twisting action will cause major hell inside the case. And if you aren't going to somehow drill the entire battery out(without hitting the circuit board), you'll have to work the husk out with the spot-welded on tab. In fact, just imagine your bit biting into the battery, and the spot welded on tab spinning like a metal weedwacker blade inside the case. Seriously, try the "round and around" with a sharp razor or a super fine jewels saw blade - the gap is not the big.

[I'm being facitious here...don't miss that!]
The potting gel around the wire bonds of the main IC was ingenious all right - greatly increases the likelihood of you destroying it when attempting to open it. A brilliant design feature. Just think, they could have done what some really stupid manufacturers did - covered them with epoxy or thermosetting plastic or something else that would actually protect the wires and prevent damage in one stroke. Glued shut case, filled with sticky snot - what's not to like. But a real cool piece when they are working.

[clockace]

amen to that. i think, from what i have seen, the black bottom comes in several different configurations. the 2 i have tried to open had a very deep bottom with cell recesses molded right in the bottom and they snapped right in there securely. from some photos on the forum of the mkIV modules it looks like the black bottom has no recesses for the cells and has a narrow edge where it meets and is glued to the red top. if that is the case, it would be much easier to remove the bottom merely by going round 'n round with a sharp blade or jewelers saw[my preferred method] just like the mkI/II's. the rwr legacy i have[#23] looks like that under a strong light. i can see the cells thru the red sides. you could not see the cells on the 2 i opened. the black bottom had an edge at the glue line that was at least 2+mm into the red top. that is why i made 2 cuts close together with the saw. one cut and prying would just tear up the red top edge. that is what began to happen on the 1st one i opened. then i tried to just slice the black bottom off at the seam with the saw. that worked, but all i could see after i got it off was the tops[what was left of them] of the 2 cells. i also ruined the display by going too deep and cutting some of the digit tracks. this is the one that howard has and is supposed to be rebuilding for me? trial and error is one method of learning when you don't have any other source of info. that is why this forum is so valuable. the advice and warnings of us who have gone there and messed up should give others some benefit of what NOT to do. enough rambling for now. peter

[Sully008]

I'm going to add my 2¢ as well. I've only opened one black bottom case so far, and it is the one with the deep wells that clockace is talking about. I used a large Olfa box cutter to cut along the seams. It came apart okay, but I did go too deep in the front display area as well, and sliced part of the bottom of the display off. Was pretty upset until I realized that it was no good anyways, alot of the traces were eaten by battery acid.

I have one more dead Synchronar coming. It's a Mk III/IV that I'm going to try and open without damaging anything.