Resurrecting A Vintage Numitron Board
Added 2024-03-29 03:53:05 +0000 UTCBack to the bench for some adventures...
Comments
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Michael
2024-04-06 17:44:30 +0000 UTCWell... Numitrons (and their Russian IVx equivalents) were heavily used in aviation applications, including fighters. They were favored over Nixie tubes and even (in their latter days, even into the 1990s) over LEDs because of their daylight readability and their ability to be filtered to any color. The data sheets for some of the RCA tubes are quite, er... illuminating. For the DR2100 tubes in this board, some of the interesting specs (directly from the data sheet): Mean life expectancy (95% confidence): 100,000 hours Maximum impact acceleration (operating): 100g Peak vibrational accelerations (25 Hz, 96 hr): 2.5g DC segment voltage: 4.5V The Russian devices (IV9 and IV16 are the ones I've used) are similarly rugged, although with shorter rated lifespans - only 50,000 hours at rated filament voltage. I can't attach a picture to this comment, but a curve of segment voltage versus life in the same document shows the segment life geometrically reaching 10E7 (10 million) hours at a segment voltage of 3.5 volts. I've used Numitrons pretty extensively in a wide variety of applications. Sometimes I've used techniques to avoid thermal-shocking the filaments (generally low-percentage PWM rather than a resistor), but even without that I've had exactly zero electronic failures in equipment that has run continuously for well over a decade (my bedroom clock is a good example). The sole failure I've had was on a Burning Man Mutant Vehicle where the Numitron (actually a Russian IV9) was hit by a flying piece of debris, cracking open the envelope. Even in that state the tube lasted for a couple of hours before burning out. In short, Numitrons are very rugged devices indeed, and soldering them into a circuit seems little more short-sighted than soldering in an electrolytic capacitor. I really like using them, because they are so easy to drive, plus I really like their vintage look.
Mark Moulding
2024-04-04 03:26:19 +0000 UTCEvery one of your videos about vintage displays is an "Oboy!" moment for me. Thanks!
Andy Ihnatko
2024-03-31 18:41:29 +0000 UTCYea... Numitrons were never intended for high impact environments.
Fran Blanche
2024-03-29 22:28:46 +0000 UTCI do like Numitron displays, I have a watch from Ukraine which uses old Soviet era tubes with modern electronics. It has a touch sensitive button to turn the display on for a few seconds at a time, I do worry about how long the digits will last though.
David Peaker
2024-03-29 12:06:37 +0000 UTCthank you Fran. I absolutely love these old display videos. The digits look very crisp. I hope you get lots of views. Keep on reverse engineering.
jmk
2024-03-29 07:06:36 +0000 UTC
