Litronix Series 3000 LED Time Computer 1970s

[DrAlis]

Out of curiosity, I bought a non functioning LED time computer aka watch. If someone here has ideas on how to repair them, please get in touch or share here. When I opened it up, I was baffled to basically see totally exposed, unpackaged integrated circuit dies in there along with rather early LED number displays made out of dots. For visual enjoyment, I wanted to share the pictures with you here. On the overview picture I put it next to a Pulsar 301 Module for comparison. Basically if you touch the IC side, you likely at least bend or break or short a bond wire and kill the watch, right? No surprise it does not work. Let me know if you like it.

 

[Eudimorphodon]

The display chips on that look possibly identical to these mystery LED display modules I picked up in a surplus store grab bag a while back:

They don't have any obvious maker marks on them but there's a good chance they were made by Litronix because I've bought other LEDs from the same store that came with Litronix labels on the bags. (Several sacks of *very old* red LEDs; they have the standard through-hole dome shape, but instead of uniformly "glowing" like more modern LEDs they have a tiny red spot inside that has a pretty narrow viewing angle though the top of the dome.)

 

[daver2]

They are a thing of art now.

The non-encapsulated silicon devices are an in-built, guaranteed failure mode designed not to have a long life!

Dave

 

[DrAlis]

They don't have any obvious maker marks on them but there's a good chance they were made by Litronix because I've bought other LEDs from the same store that came with Litronix labels on the bags. (Several sacks of *very old* red LEDs; they have the standard through-hole dome shape, but instead of uniformly "glowing" like more modern LEDs they have a tiny red spot inside that has a pretty narrow viewing angle though the top of the dome.)

There might be Litronix written on the PCB like in img_030. They certainly look similar and Litronix was the global leader in LEDs. They marketed the first digital electronic watches as maintenance free with no moving parts, basically made for eternity...

Also, I just noticed that on the left digit in img_030, only the LED segments for the number 1 are wired, as that would be the only thing ever displayed on the left most digit of the watch. They certainly did not waste any resources in this design.

 

[daver2]

>>> made for eternity...

Hmm!

Sales and marketing babble...

Dave

 

[Eudimorphodon]

FWIW my LED modules work fine, I sussed out their pinouts a few months ago, but they *are* completely embedded in epoxy cocoons. And, amazingly enough, after pulling one out of the bag to check I can confirm that my displays are in fact *exactly* the same ones as what's in the watch, down to the R73 model number. Pretty amazing how modern cell phones have cameras with enough pixels to pull this off...

 

[DrAlis]

How cool is that! I dug out my Hewlett Packard HP-35 and but looked deep in the display IC. No identification to be found though.
Hey but you got an extra decimal dot there fellow

 

[DrAlis]

And I do need to know what phone you are using. My iphone can not do that, I am forced to use a cheap chinese magnifying thingy.

 

[Eudimorphodon]

And I do need to know what phone you are using. My iphone can not do that, I am forced to use a cheap chinese magnifying thingy.

It’s a Samsung S23, one of those phones that has three separate lenses on the back; this is the 3x optical zoom barrel. I would *guess* one of the similarly equipped multi-barrel high-end iPhones (Pro/Max) should be able to do the same? Only iPhone I have in the house is a 13 Mini with just the standard and ultra-wide options so, yeah, isn’t going to cut it.

 

[DrAlis]

I got an iphone 16 pro max (also three lenses) and this is the best i get with my closest 5x lens. sell those apple stocks i guess. is it an ultra s23 or regular?

 

[Eudimorphodon]

I got an iphone 16 pro max (also three lenses) and this is the best i get with my closest 5x lens. sell those apple stocks i guess. is it an ultra s23 or regular?

Just the regular S23. You were definitely using the telephoto lens when you took the shot? Because, yeah, that's really bad. The way I took my shot was I picked the 3x telephoto sensor, backed it all the way out to avoid any digital scaling (digital zoom does *weird* things) and then just held the camera as close as I could and still have it get a sharp focus when I manually clicked on a focus point. From that I cropped the close-up.

Just for laughs I grabbed the iPhone Mini and decided to see if there would be a difference in what I could get from the 1x lenses, to make it fair? The specs say both phones save their shots as 12MP (although apparently there's a 50MP sensor in the main barrel and there's a hidden option to get 50MP shots out of it? I should try that...) so in theory it should be even, but... well, this is what I got:

iPhone:


Samsung:


I wouldn't say there's a *lot* between them, but you can definitely see more detail on the Samsung photo. The main thing I noticed when taking the shots is the iPhone wouldn't focus sharply unless I held it almost a foot away, while the Samsung can focus as close as about six inches, which would explain at least some of the difference. I guess someone at Samsung likes taking macro shots because I've been really impressed with their ability to do closeups since the S5.

P.S. I tried that almost undocumented 50MP mode with the 1x lens, and it's kind of nuts; it's not *quite* as clear as what I can get with the 3x optical zoom element (which actually only has a 10MP sensor), but it's almost good enough to read the text. Almost...

 

[Eudimorphodon]

How cool is that! I dug out my Hewlett Packard HP-35 and but looked deep in the display IC. No identification to be found though.

I think HP was manufacturing their own LED displays back then so it's probably in-house? Coincidentally enough, most of the other LED displays in that grab bag I got the Litronix in were made by HP.



HP spun off their LED tech in 1999 under the name Agilent; that got carved up again in 2014, so now if you search that part number you'll find you can still find that same display is being manufactured by Broadcom.

Poor Litronix got absorbed into Siemens sometime in the early 1980's, so I can't imagine there's anyone still churning these things out.

Hey but you got an extra decimal dot there fellow

Doesn't your watch have a little blinking colon between the hours and minutes? You should zoom in on that and see if the elements for that look like my decimal points.

 

[1944GPW]

Here's my Litronix 1100 calculator. Dad bought it sometime late 1973, maybe early 1974. It cost a fortune here in Australia and we all absolutely marvelled at it when he brought it home.
Within the year we were living in Japan (IBM posting) and our eyes nearly fell out of our heads when we saw the calculators in Akihabara.
They were all super high quality, the variety and styles were endless, had proper floating point and the cost was amazingly cheap. The Litronix sadly looked like a piece of junk in comparison.

Anyway just posting this because the Litronix LEDs are different to the above. They are three digits grouped in three units. I took the close-up with a lens from a scrapped HP laser printer stuck onto my old Pixel phone with a piece of Blu-tack. Here are two I have, they have coated lenses in a metal housing and are actually pretty high quality.