Homemade LED Clock Stands Test Of Time

In an era when you might get chastised if your mobile phone is more than two years old, it’s easy to forget that hardware was not always meant to be a temporary commodity. We acknowledge a few standout examples of classic hardware still surviving into the modern era, such as vintage computers, but they’re usually considered to be more of a novelty than an engineering goal. In a disposable society, many have forgotten that quality components and a well thought out design should give you a service life measured in decades, not months.

A perfect example of this principle is the beautiful LED clock built 40 years ago by [Davide Andrea]. A teenager at the time, [Davide] built this clock to be used by the local radio station, as clocks that showed seconds were important for timing radio shows. Finding it in storage recently, [Davide] took to the /r/electronics subreddit to report that it still works fine after all these years.

Cracking open the case shows a unique and highly functional construction style. Notches cut into the side panels of the case accept individual protoboards in a “blade” type configuration, with the blades connected by a handful of individual wires. No digging through the parts bin for a “worthless” old IDE cable to tear up back in the 1970’s.

There’s a surprisingly low part count inside the clock, owing to the National MM5314N IC which does all the heavy lifting. The MM5314N is still available if you want to put together your own vintage-style LED clock, but $20 a pop may be a bit hard to swallow for nostalgia. Though if you ever needed proof that the chip can be counted on for the long haul, this is certainly it.

The design of this clock reminds us of something from Heathkit, which is about as high a praise as you can give hardware from this era. Though we have to admit, switching out those eight segment LEDs for some sweet animated OLEDs would make it a pretty awesome addition to the office.

17 thoughts on “Homemade LED Clock Stands Test Of Time

  1. Counting the transistors down either side of the chip, six digits, seven segments and a colon…

    Look at the back of the boards, yup, that looks like how they’re wired!

    Do I check the datasheet to be sure? Naah.

  2. Using a VLSI chip literally takes all the fun out of it. I built a clock with the same chip in the same era. While it was much more cost efficient than going all TTL, it lacks the coolness factor. I have an old Chronolog clock that is all TTL powered. That is a pretty cool piece. Back in the day I had the clock module for a bank clock that drove strings of incandescent lights. That was wicked cool. It was all electro mechanical, with a timing motor and cams and stepping relays.

  3. I have an about 40 year old LED alarm clock in use, although it’s not hand-made by me, it’s from korea I think.
    Anyway it’s funny how those things last, you can hand them down in the family.
    And the LED that are on 24/7 also don’t seem to have issue lasting, and without going all odd. And think about it, 350400+ hours of constant operation, where a good LED light bulb (much brighter of course) is rated at 25000 hours.

  4. A clock never changes, thus can’t become obsolete. Telephones were like that for many decades, simple and plain, they or the network never changed so the phones just kept on working.

    Again I’d point out that in 1971 the average home had very little electronics, a radio or a tv set, a stereo. Maybe some homes had microwave ovens, but fir the verge home, there wasn’t much to buy.

    Within five years, it had changed. Digital clocks, digital watches, pocket calculators, computers, VCRs but maybe they were bit later, plus all previous electronics were up for grabs, the shift to solid state, the improvements from ICs that allowed digital tuning and other things in TV sets and radios.

    Some if that brought obsolescence, because early iterations were primitive or improved on. So LED watches didn’t last, thy used too much current, and having to press a button to enable the display was cumbersome, at least once LCD displays became cheap. Pocket calculators had limited functions and LED displays, replaced by LCD calculators with more functions. The first home computers were expensive and limited, later generations got cheaper with better specs and more integration.

    Things have slowed down, because so much has changed that there’s less room for improvement. For a while, things evolved to reach some point where things were good enough, then only incremental change happened.

    At the same time, things got way cheaper. As demand ramped up, better manufacturing dropped cost, but so did better integration and cost cutting. Some were willing to spend a thousand on a VCR, but that allowed demand to grow so prices could drop, which in turn caused greater sales, etc. People wanted cheaper, and that meant cost cutting. Take out as much metal as possible, the item then becomes more fragile. Or make something “dumber”, all those modems that relied on the computer’s CPU, and that too makes things cheaper. Repair was always expensive, but if the thing cost $1000 repair was cheaper than buying new. But as prices dropped, repair cost became more significant, especially if buying new meant getting something better.

    My KIM-1 from 1979 was incapable of keeping up, it really is obsolete. I suspect my first printer, bought in 1982 for $500 is still working, wherever it is, but it was an awful printer back then. So it might still work, but is actually obsolete.

    A fifty dollar printer isn’t meant to last. But people don’t want to spend more. I suppose there is some obsolescence going on, but it’s a fine line. Hardware and software are separate, yet work together. So is that hand me down iPad obsolete because things have evolved, or because Apple didn’t build it for evolution, or they don’t want to support it? It gets tricky, things do change, at what point is it no longer feasible to keep the old going? A toaster never changes its functions, the only criteria is whether it can keep doing it. A computer may not be able to run recent software even though the hardware keeps on ticking. A cassette deck is obsolete because nobody wants to play cassettes anymore. And of course some of it is consumers, led to believe they need the latest, or just wanting it. That 3GHz refurbished computer I got in 2012 still works fine, hardware and software wise, but I wanted something better (but at least the “new” computer is a refurbished one from 2011).

    My grandfather’s pocket watch still keeps time, I don’t know how old it is, but I’ve had it for 37 years. An LED clock is neat, but didn’t “obsolete” the pocket watch, or any previous clocks or watches, since all they are doing is telling the time.


    1. “So LED watches didn’t last, thy used too much current, and having to press a button to enable the display was cumbersome”
      And there there was the apple watch. And then you wonder why they didn’t use a the ‘flick’ activation on the original LED watches, since they could have made that even mechanically.

      Incidentally you forgot some ubiquitous tech that was there way back in the 70’s home: refrigerators and washing machines (and cars in the garage I guess).

      1. The reason they didn’t use “flick” activation on watches in the 1970’s is that the technology didn’t exist yet. And even doing it with some kind of mechanical scheme would have been very marginal. Mechanical things have to be precision manufactured and they wear.

  5. http://richfiles.solarbotics.net/eb/NixieClockSeconds.jpg

    Made this puppy from the leftovers after restoring a Sony Sobax ICC-600W calculator. I had two nonfunctional machines, and used one as a donor to restore the other. While not gate level TTL, this one uses chains of 4017 decade counters as dividers to reduce the US 60 Hz AC line frequency down to the necessary time increments. Of course, I’m using nixies instead of LEDs, but other than that, it’s a good old homemade clock!

      1. Oh that’s a classic, and an old favorite of mine! Cold cathode switching is something of a holy grail project for me. I haven’t built one yet, but I can’t die happy till I finally have. I have an entire bin full of Russian thyratron tubes (around 100 or so pieces), and I own 6 ANITA decade counter/nixie display boards from an old ANITA Mk7 (Wish I had the complete machine, but someone had parted it out ;_; and sold the leftover parts on ebay, so I bought what I could). My goal is a cold cathode based calculator that uses the ANITA boards as the main counters and displays, and uses a custom control setup to manage. In an ideal world, I’d have a nixie calculator/clock combo. Haven’t figured that one out yet.

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