Those are very valuable tubes, so if you are willing to design your own driver and the PC board, I would do that. I've made several clocks and never had a design problem that affected the tubes. Even if you find a board to purchase, see if any of the following apply:
Some of my suggestions:
#1. I dont like sockets because they put stress on the tube pins. Some of them grip the pins very hard and it's difficult to insert or remove the tubes, which adds to the risk of bending or breaking the pins or putting stress on the glass. Instead, I use socket pins soldered into the PCB, and the force to insert/remove tubes is very low.
#2. Direct drive. There's no need to multiplex individual tubes, and there's no cost benefit when tubes are worth hundreds of dollars apiece and the drive electronics is at most a few dollars. Multiplexing requires higher current, and that degrades the tube's lifetime.
#3. Use a current regulator, and set the current at the recommended spec value; too high and you wear-out the tube. Too low and you risk cathode poisoning. A single anode resistor per-tube is OK, but as the anode voltage varies, so does the current (no such problem with a current regulator, though). You can mitigate this by using a higher anode supply voltage and larger anode resistor, at the expense of more wasted energy. As tubes age, their striking voltage may increase, so having a higher anode voltage will help mitigate this.
#4. PIR sensor. Turn off the tubes if nobody is there to watch them.
#5. Protect the tubes inside a case, and make sure there is enough ventilation so the heat doesn't build-up inside. On my later designs I have a thermal sensor (sometimes several) so that software can monitor critical temperatures and shutdown if things get too warm.
#6. Depoisoning routine to exercise all cathodes.
#7. Backlighting (or base lighting). I havn't done this on any of my clocks, and I've never had problems with tubes not firing-up. Others have reported problems without backlighting. It can have aesthetic value, though I'm not fond of it.
That should cover the necessities for the tubes; there are always lots of other features that can be done, especially if the clock has open-source software (or you develop it on your own).
On Tuesday, September 17, 2024 at 8:17:28 PM UTC-7 Chachi88 wrote:
I am climbing stairs from the foot of the mountain to sit at the feet of all you nixie gurus.
What is the current state of the art for remote driver boards? I am aware some of the older drivers are not as reliable or can cause the tubes to degrade quicker. Some of the new options I am seeing have "cathode poisoning prevention" I have recently come upon qty 6 of the NL8091's and their original sockets and socket mounting plate, which I wish to reuse for a clock. Are there any off the shelf boards even capable of driving this tube? I was looking at a board on ebay that comes with an IR remote but it seems too good to be true, I would be willing to spend 5 times as much for a board that was properly documented and put together and had some sort of pedigree...
Thanks in advance for any advice or direction you can give.
