Modern, Frugal PCB Breathes New Life Into Soviet-Made LED Watch

A vintage watch with a new PCB inside, next to a 3D rendered image of the PCB

The first electronic digital watches were admired for their pioneering technology, if not their everyday practicality, when they were introduced in the 1970s. Their power-hungry LED displays lit up only when you pressed a button, and even then the numbers shown were tiny. Their cases were large and heavy, and they drained their batteries rather quickly even when not displaying the time. Still, the deep red glow of their displays gave them a certain aesthetic that’s hard to replicate with today’s technology.

A vintage LED watch displaying "16.42"
Pressing the top-right button enables those beautiful LED modules

When [Benjamin Sølberg] got his hands on an Elektronika-1, a first-generation digital watch designed in the Soviet Union, he set about designing a modern replacement for its internals. Where the original had several custom chips wire-bonded directly onto a substrate, the new board contains an MSP430 series microcontroller as well as an AS1115 display driver. The PCB makes contact with the watch’s pushbuttons through clever use of castellated holes.

For the display [Benjamin] went with period-correct LED modules made by HP, which keep the display’s appearance as close to the original as possible. While these draw quite a bit of current, the rest of the watch has become an order of magnitude more frugal: the stand-by time is now estimated to be about ten years, where the old design often needed new batteries within a year. [Benjamin] uses his renovated watch on a daily basis, apparently without trouble.

If you’ve got an old Soviet digital watch that you’d like to upgrade, you’ll be pleased to hear that the entire design is open source. Just like this retro watch, in fact, that uses a similar LED display. If you’re into original vintage watches, we’ve covered them in depth, too.

12 thoughts on “Modern, Frugal PCB Breathes New Life Into Soviet-Made LED Watch

  1. We got LED watches because they were new, and “futuristic”. The main point was they were digital, rather than a watch with hands and a dial.

    As I recall, the first digital watches were LCD, very expensive. That includes the digital watch project in Popular Electronics in 1973 or 74.

    But then TI released their digital watch in 1976 (or was it 77?). I think I paid $35 for mine. It was about getting a digital watch, that it was LED never entered ito it. There was nothing cool about pressing a button to view the time, it was a way to get a digital watch.

    The TI certainly wasn’t big and bulky. The Casio G Shock I got three years ago is bigger.

    LED watches lasted a brief time. There are books and movies that have them, because they were cool at the time, but I suspect few know what’s being talked about now.

    In 1980, I got an LCD watch for about the same price, with more features, for $20 or $30.

    1. Well, it has it’s own charm though, imo.

      But as it has quite a strong microcontroller on it, it might be nice to see if one of those 5×7 dot-matrix led display would fit, like the DLO1414 or HDLG-2416. That could enable some nice extra smartwatch-like features. At the cost of a little less vintagy feeling.

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