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12 thoughts on “Dissecting a vintage led clock – for science!”
  1. Avataaar/Circle Created with python_avatars elektron2kim says:

    I had a good one in the 70s and it was mainly a radio and I could mess my alarm up with a turn off timer for the radio channel I chose to fall asleep with. I was fascinated by the complicated constructs the light was coming from. It served for many years and I don't think it broke. It got replaced by something more precise.

  2. Avataaar/Circle Created with python_avatars Walter Knox says:

    I have this same clock, used it for many years. It definitely is not as bright as it used to be, but it is still very visible, and I really like the old red ones like this much better than the overly bright green ones. The only thing about this one is that it makes an audible buzzing sound when not displaying all four digits.

  3. Avataaar/Circle Created with python_avatars Jim Hendrickson says:

    Cool teardown. I was looking for a large-ish 7-segment clock display for a project and haven't been able to find much that's reasonably priced, and I have a digital clock of similar vintage (early 1990s) that I haven't used in years, with a large display like this one. I thought of pulling it apart, thinking it would be a self-contained module (like the small ones you can get at Adafruit). Seeing this I now realize that I'd probably just end up with a busted clock and a display that wouldn't be as useful as I thought anyway. I guess I'll keep looking or come up with a custom solution.

  4. Avataaar/Circle Created with python_avatars White Sapphire says:

    So what we're really seeing here is Fran, the avid VHS video viewer, has bought two videos, and the seller padded out the box with a digital alarm clock to protect the cassettes in transit!

    There's nothing quite like crunching noises pervading the air at breakfast time, only it's alarm clocks, not corn flakes, on the menu today.

  5. Avataaar/Circle Created with python_avatars David G says:

    When they came out with green LED's I went to great lengths to find a green LED clock and immediately regretted it, it lit up the room way too much at night. I put the red one back in the bedroom and the green one went in my computer room with all the other bright LED's. Then we had to wait decades for blue ones which are a great discovery but pretty annoying indicators IMO.

  6. Avataaar/Circle Created with python_avatars MisterTalkingMachine says:

    Early LED devices have been my recent obsession (though more of a resurged obsession from my childhood) so this was a treat, even if the diodes aren't that old. There isnt that much to read about the specifics of early LEDs that I can find, I remember there used to be a website that had photos of several unusual diodes, including an early SiC blue LED that had survived a lightning strike. I'd love to see that photo again because now the resilience of SiC LEDs against lightning is more of an urban legend.

  7. Avataaar/Circle Created with python_avatars Martin Schultz says:

    Had to wait until I got home and check but I have the same clock with slightly differently shaped buttons, same exact shape to the case, same name. Label on the bottom of mine has no instructions. Not sure when I bought it, late 80s or early 90s. It's been running continuously since I got it. Over the decades it's been moved between different rooms, the dim display is great for a dark home theater room.

  8. Avataaar/Circle Created with python_avatars High Voltage Hot Dog says:

    I've taken apart quite a few bedside LED clocks over the years. The TMS3450 is a staple of 80's and 90's clocks and clock radios. It has a pin that can be set for 12-hour or 24-hour mode. Unfortunately, the LED board is not populated with the A, D, E, G segments for the left-most "2", so you couldn't use 24-hour mode anyway if the clock was still in one piece.

  9. Avataaar/Circle Created with python_avatars Jason S says:

    When I started working at Radio Shack in the early 90s right out of high school, I enjoyed experimenting with all their gadgets on display when it was slow between customers. I was like a kid working in a candy store with free samples!

    I remember discovering that effect of LED segments alternately disappearing on video camera due to their multiplexing rate differing from frame rate on the camera. Another effect I discovered was pointing a laser pointer's tiny dot at the unlit segments causes the entire segment to light up due to its diffuser spreading out the light just like it would from the LED coming from behind.

    Luckily I worked in a mall that was very slow and had lots of time to experiment with things and open them up and figure out who made some of their private label products. Many actually came from the makers of well-known brands like Sony, Uniden, Aiwa, Casio, Sangean, Eveready and Pioneer, and others were custom products designed specifically by or for RS. They once owned some factories of their own but had been transitioning away from those around the early 90s. They made their own coax cable, antennas computers and cassette tapes, for example, with factory photos even appearing in their catalogs in the late 70s and as late as the early 90s they mentioned owning and operating as many as 33 factories in 6 countries including the US.

  10. Avataaar/Circle Created with python_avatars bigclivedotcom says:

    I accidentally destroyed my first LED digital clock by damaging one of the wire bonds onto the LEDs while exploring it. The modern clocks use small surface mount chips in the same light-box system. That classic clock chip was super-popular. They usually get a timing reference from the mains frequency with a solder pad to select 50 or 60Hz. I wonder why the diode's chopped.

  11. Avataaar/Circle Created with python_avatars Spehro Pefhany says:

    What about bezel vs. escutcheon ? 😀 1980s will probably be marked "Made in HK" or "Made in Taiwan" rather than China, if memory serves (and it may not). Notice all those holes drilled or punched in the display PCB to break the shorts required for gold electroplating.

  12. Avataaar/Circle Created with python_avatars beautifulsmall says:

    Went into an electrical wholesalers this week and saw boxed reels of led's on strips. Not seen it out of the hobbyist scope before. Not neopixel but lots of variety. I feel the fustration of old plastics. Ive got many enclosures with rattling bits inside, almost always a clip. Those dies are tiny for pcb assembly early 90's.

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