Instar Stem-set

[charger105]

I recently acquired this Instar LCD Stem-set, in a job lot:




It has an interesting stem-set module, similar to an Optel, but I don't think it is. The colons are not diamonds either (just little squares).
To advance the hours, you just rotate the stem counter clockwise.
To advance the minutes, you pull out the stem, and rotate it clockwise.

Does anyone know anything about this watch, or this module ?
Rgds,
Andrew.

[rewolf]

Tis looks familiar, especially the wires across the plastic part of the stem module - but I don't know where I've seen it before....

[retroleds]

The module is made by Microelectronic Systems, Corp....which also made the "MIKE" brand watches and modules and the Pantera. I this and a front picture over in the "LCD VINTAGE - L-Z" area of the gallery(I am not hot-linking to those pictures as there is an upcoming, long-awaited change to the gallery software coming. At which time I will port all of www.ledwatches.net to the gallery).
loaded

[retroleds]

Oh hell, you got me wanting to fix one of these that were in the "triage" box. Pull small screw from stem switch, pull three screws holding front of module to back. Voila! What a weird construction, eh?! Don't lose those little gold springs . The display is a sealed unit, with the contacts on the back, so give those a good cleaning before screwing with the electronics....BAMM, this one fired right up.
Re-assembly tip: line the hole up in the stem with the piece it inserts into on the switch by sticking a needle in the hole where the keeper screw was...pull the needle out gently once aligned, stick your screw to the tip of your screwdriver(I use either part "A" or "B" of some epoxy for some stickiness:-)). No further instruction is needed on the screwing I assume.

[rewolf]

Now THIS is an interesting module construction, never seen one like that.

A carrier board with battery contacts, stem setting mechanism and LCD voltage converter. Attached to its bottom side on a second board is the passive part of the oscillator circuit (quartz crystal, trimmer and capacitors). Finally the chip+LCD is on a ceramic board contacting the carrier board via eight spiral springs.

Really weird and certainly not cheap to manufacture...

[digibloke]

This is the same module that was used in the Gruen LCQ teletime watches - (largely regarded as the first commercially available field effect lcd wristwatch).

It's also used in the westclox quartzmatic stem set watches, Seth Thomas produced watches using it and shortly after the novelty value wore off and the price came down it was used in all sorts of different brand watches. (theres a lovely Micronta on ebay right now and I'm pretty sure that Heuer also produced a watch using this module).

It's a cracking piece of engineering. The three pieces making up the module are all easilly interchangable/swappable and they made a lot of these so it's not too hard to find parts for repairs.

(Ed - have you been soldering your pointing finger again?)

[charger105]

Thanks for the replies.
It does look like a quality hand-made module. Do the Gruen and Westclox use base metal bezels or SS ? The quality of my watch seems a bit diminished by the base metal bezel.

Someone had obviously tried to remove the stem housing on my module, as originally I couldn't set the hours. I eventually noticed that someone had cut one of the wires on top of the housing where it runs down to the PCB (it looked like it was still connected, but a magnifying glass showed where it had been cut). I soldered them together and hours could now be set. My question is, should the other wire be connected somewhere (shown below in red circle):



I only have a single function.....time ! Should this wire be connected to provide other functionality ?

Rgds,
Andrew.[/img]

[digibloke]

All of the watches I've got with this module have base metal bezels. Certainly the Gruens and Westclox ones do. I agree - it seems a shame as they'd have been lovely in stainless and they often show brassing nowadays (Luckily there are still sometimes NOS watches on ebay).

That wire seems to make a connection before the end so I think your watch is just fine. All it should do is set properly and show the time with the colon blinking to show the seconds.

[retroleds]

Andrew - only time on those. When you let go of the minute setting, seconds start at zero. It is a weird board construction - almost as strange as a Heuer Chronosplit LCD/LED. If only the Heuer has used little gold plated springs like the watch at discussion instead of 5 separate rubber zebra strips, we might have more of them that are working. The Microelectronics Systems, Inc. headquarters was only about 1/2 an hours drive away from where I currently live and very close to a General Dynamics Tank plant....they also made specialized electronics for the USA government.

With minimal effort a guy could put that module into any 29mm case with a button or setter at the 3 oclock position. But I agree - why the crap cases? Final thought, if turning one way works but not the other - generally someone bent the screw that holds the stem in whilst turning brutally one direction, causing it to stop short of it's proper rotation the other direction. The switches themselves don't seem to go bad very often. You can verify function of the switch while the stem and keeper screw are out, by rotating the plastic hub the stem slides into with any small tool(I use pointed toothpicks a lot since they don't chew things up like metal....quality bamboo ones can even remove most clasp springbars easily with no fears of slipping and scratching. You can often turn those bent screws in/out a 1/4 turn, putting the "bend" parralell to the stem, where it doesn't affect function.

[charger105]

Thanks for the replies gentlemen.
It's setting fine, and running fine, so I don't think I'll fiddle with it any more.
In a huge co-incidence, I received a Gruen teletime in the mail today ! It does indeed have the same module, and that second wire connects down to the PCB on this one. Perhaps it's a link to reset seconds to zero when finished setting the minutes ?

Anyway, as mentioned I think I'll leave well alone.
BTW, the Gruen works and sets perfectly.......now I've got 2 of these modules that I knew nothink about a week ago !

Thanks again.
Rgds.

[azimuth_pl]

ehmm
details revealed already in AD2005.
http://crazywatches.w.interia.pl/photo/ ... etime.html

module made by AMI - American Microsystems Inc.
not all of them have the wires mounted identically although they work the same way.
the Gruen LCQ as pictured (Teletime MkII) is available in all steel.

[rewolf]

ehmm
details revealed already in AD2005.
http://crazywatches.w.interia.pl/photo/ ... etime.html
...

Now I remember where I'd seen it before and why it looked familiar....