Quote:
Originally Posted by The Philpott
Interesting project, especially if you can retain the original functions.
As a clock the display will of course have a 100% duty cycle, it might be appropriate to check that the ventilation is adequate for constant use..?
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Well, "as is" there is
no ventilation at all! The case is a single block of plastic and except for a small slit on the back panel, air cannot flow freely. As I will be running it on the desk while troubleshooting, I will check drivers temperature.
I have located the HV line going to the anodes and it can be interrupted easily if necessary to keep temperature down. Nixie clock builders like to use PIR sensors to detect presence/motion.
Meanwhile I have found a scan of "General Electric Glow Lamp Manual, 2nd Edition" at
http://w5jgv.com/amateur_radio.htm#downloads that lists indicator bulbs. I might be looking for a NE-83 or NE-86, all variations of the NE-2. The document mentions radioactive doping on some of those lamps, so I'll check mine for possible weak residual activity too.
For the curious, building a clock with a voltmeter is straightforward: a modern microcontroller (Arduino and the like) generates a PWM proportional to the time of the day as expressed in Volts, and the DVM does the rest. And if the 8-bit resolution is not enough (256 steps), add a small D/A converter.
BTW, since this multimeter will count up to 1999, it can display 19:59 as a time and then loop to 8:00 pm.
Hopefully I will have time to continue troubleshooting this upcoming weekend.
Paolo