Jan. 1974 Pop. Elec. LCD watch kit article

[redled]

Has anyone seen this? Is it posted online anywhere? If not I can scan and post.

[AlmightyTallest]

Well, I'm interested :D

that's a pretty early LCD they're talking about, if you find the time to post it up redled I know I'd appreciate it :)

[retroleds]

Here it is gentlemen:
http://www.ledwatches.net/articles.htm#PopEleLCD

Directly below that is an article from same issue on the "quartz crystal shortage of 1974". And we wonder why so many were of low quality

[redled]

Thanks for posting them for everyone Ed, they look great.
[Site admin. interjects, again] No, thank you! We need this kind of input...it will be there for posterity. My apologies for not crediting you directly.

[redled]

No need to credit me, the work involved was minimal, i'm just glad there's sites like yours to serve as a central locatiion for this type of thing.

It's interesting to get a glimpse of where the market was at that point in time. The article mentions LED watches were generally at the $200 level, but the fact that the watch kit was available for $80 was a clear indication of where things were going, and fast.

The specs for the watch also give a possible explanation for why LED held on for as long as it did; the LCD display was only rated down to 50 degrees F. The article mentions body heat helping, but still the display is mounted towards the outside just under the crystal. It probably didn't take much to get it below 50 degrees. It would be interesting to see how it performed in the real world. I wonder how many kits they sold, or if one of these will show up on ebay some time. My guess would be they sold a lot, everybody wanted a digital watch back then!

[retroleds]

I just got the August 1970 edition of Radio Electronics - they review the Hamilon digital watch and have plans so one can build their own LED clock. August 1970 - big 5/8" tall LEDs, build it all on a breadboard and stick it in a box of your choice. WOW!! 8) I'll get those up soon.

[redled]

Wow a Hamilton (prototype) review, that's great!

This is another aspect of LED history I find fascinating; the almost 2-year gap between the announcement and the availability of the watch. I suppose it shows just how difficult it was working with a relatively new technology that would in effect displace a centuries old one. Once the ball was rolling though, the speed at whcih it developed, especially contrasted with the centuried pace of mechanical watch development, is very indicative of the nature of this technology.

It's also very interesting that both the Hamilton product and the invention of the venerable Mr. Rheil reached the market at just about the same time. Talk about split second accuracy...

[AlmightyTallest]

Hey thanks for the information guys, makes for some interesting reading. :D

The LCD in the Popular Mechanics article, is that a Dynamic scattering display type or a field effect type? Some of the pictures in the article to me make it seem like these kits used the older Dynamic scattering display type like the early Optel watches used.

[rewolf]

Yes, it seems to be DSM, not FE.
On page 4 it reads "Due to the optical properties of the scattering type of LCD, the display has to be tilted slightly for clear visibility..."
Also, the -15V are typcal for DSM; FE need much less voltage.

Very interesting article, it's the first time I see a circuit diagram of a DSM watch - I've been looking for this! Thanks for scanning ond posting this!

[Synchroserious]

Fellas

On the subject of early LCD I found in my dads original watch parts and suppliers bookbinder an Optel 1053 Liquid crystal clock display preliminary bulletin dated 3/15/71.An official company letter addressed to my dad offers 1,000 of these displays at ($15.00 each)The date of the letter is June 2nd, 1971.
In the same section of the binder on displays there are other suppliers including ILIXCO founded by the guy that invented the TN type LCD.The data sheet is labeled OPTILOGIC in big letters for the Bilevel Liqquid crystal displays available in white background with black letters or vice versa.One of the first customers for ILIXICO was Gruen watch of Switzerland,another close contender to the race to market the first solid state digital readout wristwatch.Obviously my father went with Monsanto Inc.,the early pioneer in LED,s and already had 2 watches working utilizing a differnt display offered by them and the early tunning fork 1968 wire filliament display version from a company in Ohio.


All I am thinking is that this kit in Pop Electronics was more or less the only way to dispense of the DSM type displays that were obsolete for manufacturers of both LED and LCD by 1974.The $80.00 is for the fun of building more than having the best display available.Still a Bargain in those days.

[bizzybody]

Wow. Surface mount tech with thru-hole components. But shrink tube wasn't invented yet.