It' here!

[jdexter]

Evening gents.

I have word back from the good folks at dynaloy, unfortunely they have nothing by way of solvent that can be used to soften the seam that doesn't scar the lexan. They do have a potential potting gel solvent, but they are not willing to say one way or the other if the solvent will address the gel unless they know what the gel is exactly. It isn't cheap, but under a $100 for a litre.

So - to recap our current Q&A list:

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

A: LED min 2.1v - IC/Quartz min 1.8v(?) || 5-10mA/30mA low/high drain. 20mA median (5-10hrs 1.5 hours low/high drain = current battery).

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

A: Effectively, the Solar cell appears to be regulated by the battery itself. Appearent max SC output at the leads is 3V, weather dependent.

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

A: Base 2.8V - unknown maxium so far.

- 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?

A: Mr Riehl was appearently considering the problem, no known examples.

New Question:

- What is the potting gel made out of exactly?

Cheers and best wishes.

[Synchroserious]

Hi, You bought the Sunwatch from me.It was from 1980-81.I can tell you that "Goof OFF" will soften the seal area but also damage the lexan unless you use at your own risk a minimal amount on the tip of a blade.No special solvent is needed for breaking down the gel.That can be done with Isopropyl(rubbing alcohol) after you open the module,70-90% is best.

Variants of GE RTV silicone were used for potting material from 1974-1995.


Some circuits can display under 1.8 volts at low intensity and others will not. You can temporarily hook up 3 volts or more without damage.

I consulted with Rewolf about the possibility of using super caps or higher voltage battery only on circuits i have that run on minimum 2.5-3 volts.I was able to fit a CR2345 inside an experimental module and it worked.Then I shelved the project.

As for the solar cell, power is always able to go in one direction only(charging) regulated by a shotky diode in some cases and or designed into the chip.

[jdexter]

Howard! Great to make your acquaintance again. Was pleased with the watch and trying to nail down some details. Any further hard data you can provide would be greatly appreciated.

So, the solar cell is regulated at the board. Great. Is the maximum output at the leads supposed to run up to 3V then cut when the battery resists further charge (or some other voltage)? Also, have you ever tried to feed more than 3V into the watch itself? If so, what happened?

Your information on gel in the more recent thread is extremely helpful. I will reply to Dynaloy regarding brand and product range and see if they have anything more specific than ISO.

Thank you very much for the watch and your time. I left positive feedback on the sale. Looking forward to getting her open.

Cheers and best wishes.

[Synchroserious]

No Problem,thank you for buying one from me.I figure as broke as I am I might as well sell some non workers traded in long ago since everyone else does.

There really is no worry of over charging the batteries.Even when the batteries are at full charge(Aprox 2.7 v) the solar cell can't pump out anymore and really can't reach more than 3v reading while connected to batteries(internal resistence in the batteries),not even two inches close to a 150 watt bulb which would burn your hand in 10 seconds or less.

I once used my power supply for something that required like 6.5 volts.Came back the next day and hooked up a watch and flipped the switch not even looking at the meter since it was rare to have it over 2.8 volts before i got side tracked(my daughter was 3 then,now 6).Came back hours later and my heart dropped and shut it down but yes everything still was A OK.The batteries did not explode either but they then were reading 3.5 volts .So i chucked the batteries and retested everything at 2v. Everything was still A OK.But in real life it is probably not a good idea to pump more than 3.5 volts for an extended period.

[rewolf]

There really is no worry of over charging the batteries.Even when the batteries are at full charge(Aprox 2.7 v) the solar cell can't pump out anymore and really can't reach more than 3v reading while connected to batteries(internal resistence in the batteries),not even two inches close to a 150 watt bulb which would burn your hand in 10 seconds or less.

Yes - the batteries act as kind of voltage limiting device.
However, a capacitor would not do so. Instead, tt would finally charge up to the highest voltage the solar cells can deliver.
So it'd be interesting to know that voltage: easy to measure with a voltmeter connected to the bare solar cells (no connection to watch circuit or battery) while the solar cells are exposed to full sunlight or a VERY bright incandescant lamp.

[Synchroserious]

Yes - the batteries act as kind of voltage limiting device.
However, a capacitor would not do so. Instead, tt would finally charge up to the highest voltage the solar cells can deliver.
So it'd be interesting to know that voltage: easy to measure with a voltmeter connected to the bare solar cells (no connection to watch circuit or battery) while the solar cells are exposed to full sunlight or a VERY bright incandescant lamp.[/quote]

Well, i have posted in the past that the solar cells by themselves deliver more than 3 volts only after someone posted they deliver 2.4 which is really the nominal rating of the batteries.

I just tested 2 in direct Florida Sun.... 3.8 and 4.0,same result for both at 5 inches to a 40 watt bulb.Are we getting somewhere?

[Synchroserious]

[/quote]Yes - the batteries act as kind of voltage limiting device.
However, a capacitor would not do so. Instead, tt would finally charge up to the highest voltage the solar cells can deliver.
So it'd be interesting to know that voltage: easy to measure with a voltmeter connected to the bare solar cells (no connection to watch circuit or battery) while the solar cells are exposed to full sunlight or a VERY bright incandescant lamp.[/quote]

Well, I posted awhile back that the solar cells by themselves can deliver more than 3V only after someone posted they deliver 2.4 volts which is really the nominal rating for the batteries.
Just tested 2 SC ....3.8 and 4.0 in direct Florida sun,same result 4-5 inches to a weak 40 watt bulb.
Are we getting somewhere?

[rewolf]

Howard, thanks for the quick test in FLORIDA SUN (here it is snowing, below 0°C, and dark night...).
3.8 to 4.0V is about what's to be expected. So 4.0V minus the blocking diodes's forward voltage (at least 0.1V for a Schottky at very low current) would be the max possible voltage on a capacitor. This sounds like it could work for the chip
But most Supercaps are rated for only 2.5V