IEE Nimo tube power supply

[Robert Norman]

 On EBay with four tubes  https://www.ebay.co.uk/itm/305672059360?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=2izFn68PQ-6&sssrc=4429486&ssuid=U1YeAcPgQ5y&var=&widget_ver=artemis&media=COPY

Not my auction

Rob

[gregebert]

Interesting that the supply mentions 3.2kV; the nominal anode voltage is 1850 volts. As with nixie tubes, I suspect the current is the critical parameter as it determines the brightness (amount of phosphor burn). And, like nixies, there is a minimum voltage required for illumination. So, there isn't an exact operating voltage that must be strictly adhered-to. Also, I have not found any info that suggests harmful radiation (X-rays) are produced anywhere near 3kV, so I wouldn't worry about getting nuked from a NIMO tube or small monochrome CRT.

I've run my NIMOs just below the 30uA current and in the vicinity of 1850V for less than 50 hours of operational time, and with a UV light source I can see slight phosphor burn. I dont run it as a clock very often, fearing that I will either burn the phosphor or burnout the filaments, yet at the same time I do want some enjoyment out of this multi-year project. Decisions, decisions......

[Mac Doktor]

On Jul 18, 2024, at 10:26 AM, gregebert <greg...@hotmail.com> wrote:

Also, I have not found any info that suggests harmful radiation (X-rays) are produced anywhere near 3kV, so I wouldn't worry about getting nuked from a NIMO tube or small monochrome CRT.

I have an induction coil and some Crookes tubes. It can reach ~15kV. At that voltage you're into the X-ray zone. Naturally I don't take it that high.

The Crookes tubes are very nice and naturally no one has them any more. I suspect there were QC problems and clueless customers who couldn't get anything to work. Here are some pictures:

https://www.astarcloseup.com/2011/08/crookes-tube-first-test.html

Note the invisible magnet.

Terry Bowman, KA4HJH
"The Mac Doctor"

https://www.astarcloseup.com

“...the book said something astonishing, a very big thought. The stars, it said, were suns but very far away. The Sun was a star but close up.”—Carl Sagan, "The Backbone Of Night", Cosmos, 1980

[Grahame Marsh]

Do we know what the green phosphor is P1, P31 or something else?

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[liam bartosiewicz]

The phosphor should be P31. I’m wondering if external deflection coils could be used to slightly alter the position of the digit to counteract burn-in.

On Jul 18, 2024, at 1:06 PM, 'Grahame Marsh' via neonixie-l <neoni...@googlegroups.com> wrote:



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[Nicholas Stock]

Greg, can you see the burn in with the naked eye or do you need the UV lamp to assess..

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[gregebert]

Only with UV, and even then it's very faint.