Nixie Tube Wristwatch
What if LED and LCD display digital wristwatches had never been invented?
Here's what might have happened...
The Nixie Tube Digital Wristwatch!
To view the time; simply press the button on the front of the watch to illuminate the Nixie Tubes. Daylight viewing is good, and night time viewing is like an orange beacon.
Why a Nixie Tube Wristwatch?... well because it had never been invented before!
The wristwatch was designed using surface mount components, and miniature NOS (1960's vintage) Nixie Tubes.
The Nixie Tube Wristwatch is enclosed in a transparent iWatch case :). You can view the miniaturized electronics contained inside.
The dimensions are only: 2.75"L x 1.5"W x 1.2"H it's very small (for a Nixie wristwatch). If you appreciate the soft orange glow of vintage Nixie Tubes, then you'll love the Nixie Tube Wristwatch. - This is the ultimate geekware - Consider the fact that nobody else in the world has even seen a Nixie Wristwatch. It'll surely attract attention when wearing it in public. Twenty five nixie watches were assembled to sell, with each wristwatch assigned a serial number. Own a piece of history for your enjoyment. Time is displayed in 12 hour format only. Time setting is accomplished using fast and slow increment buttons on the side of the enclosure. Though the Nixie Tube Wristwatch is enclosed, it is not considered waterproof. And the glass Nixie Tubes can be broken if it is dropped.
It is amazing to see how the display technology from yesterday can be integrated with the miniaturized components available today...
The Nixie Wristwatch does not have a microprocessor, or programmed components. Standardized low-power CMOS logic drive the nixies in DC mode.
A number of different circuits were considered when designing the watch. I eventually settled on the simplified logic approach, similar to the circuits used
when LED digital wristwatches were entering the consumer market around 1972. Of course, I couldn't place the circuitry on one IC chip as they had done.
I've learned some about the early history of the digital wristwatch in discussions with pioneers in the industry.
Here's a few bits of interesting history:
Did you know the first complex electronic digital wristwatch was demonstrated in 1968? The multiple IC die were attached to a hybrid carrier substrate, and the time was viewed using a four digit display of miniaturized filament indicators (like tiny numitrons), as 7 segment LED displays were not available yet!
In yet another amusing morsel:
A major manufacturer's first digital LED wristwatch was hurried to a public demonstration.
The logic circuit was TTL, and drawing 10's of milliamps of current from the tiny batteries.
While this little marvel was onstage; after a few minutes of operation, they handed it offstage
and another watch (with fresh batteries) was palmed in place of it.
Viewing the underside of the Nixie Wristwatch at 5X. The compact circuitry and miniature surface mount components are very interesting.
The 1.5v Alkaline AA display battery will last for more than six months if the time is displayed a dozen times per day for a few seconds.
Two CR-2032 lithium batteries powering the timekeeping electronics will last approx 6 mos, regardless of how often the time is displayed.
Price: $495.00 assembled. Sold out long ago, sorry...
Would you like to have a "Krusty Battery" for your own project?
Click on the image below to download an image file arranged for Avery 8253 labels.
The story of the Christmas 2001 gag gift.
It all started in March of 2001. A friend had been visiting me, and while he was looking at one of my Nixie Tube Desk Clocks, he asked "could someone build a nixie tube wristwatch?". Evidently, his question had came to him from a recent viewing of the movie "Brazil". Laughing, I said that it would be impossible to cram the nixie tubes and power supply into a package small enough to fit onto your wrist.
A few months pass, and it is now June 2001 and I am sitting in my office with a few spare minutes, admiring the simple flash electronics module from a disposable camera my wife had used. I noticed it could supply over 200vdc at 1ma of current with just three components and a single AA battery. Hey!, the nixie wristwatch might be a possibility after all. A year or so before, I bought a hundred tiny Nixie Tubes at an auction of surplus military stuff at Hickam Field in HI. They were cheap, but much too small to use them in a clock. The miniature tubes might indeed work in a wristwatch. It had to contain at least four tubes to qualify as a real looking clock, but I could cram them all together.
Thanks to the "Dot Com Deadpool", the semiconductor equipment business was in the tank. When July arrived, I had nothing on my schedule and sat down at a PCB CAD station to began modeling the various parts to see how compactly I could design a battery powered Nixie Clock. I spoke with Roger Riehl (of Synchronar 2100 fame) by telephone regarding his design approach. Since the Nixie Wristwatch was supposed to be a "missing link" that predated LED and LCD's wristwatches (tongue firmly in cheek), it cannot contain an MCU or other programmed parts. Roger built his amazing wristwatch using custom die attached to a hybrid carrier. The Nixie Wristwatch was intended as a gag gift at Christmas for close friends, and so I didn't have the resources to assemble it at the chip die level, considering production was limited by the tubes on hand.
A few days pass and I had completed the circuit board design. The circuitry was simple, based on CMOS logic that was commonplace for the brief period in history that the Nixie Wristwatch would have glowed brightly. I had a single run of boards fabricated by my usual local vendor. Good grief, I could not believe I designed it so damn small. Everything was surface mount, and some of the traces were less than .008" wide. All the parts were assembled to the first five prototypes in August 2001. Amazingly, everything fit, and it actually worked! Now it needs a case.
An associate in the plastics molding business had worked on developing the enclosure from an example I provided him. His fee was a completed wristwatch of his own. What? someone actually wants one of these silly things? Could it actually appeal to others than my own geeky nature?
At the beginning of September, five Nixie Tube Wristwatches were completed and running. Plenty of time to package these goofy holiday gifts!
Everyone who saw the watch laughed out loud, and then asked if I could build one for them. Hmmm. Could I have a cult "sleeper" item here?
After it was all over, a total of 35 Nixie Wristwatches were assembled from available components on hand. Ten were given away at Christmas, and twenty five were sold individually (some on Ebay) in the first quarter of 2002. The little gag gift confirmed a Nixie watch had broad appeal.
In 2010, I began working on a new version of the Nixie Wristwatch.
If you would like to see what the second generation of Nixie Wristwatch will look like, CLICK HERE for more information.