Just a quick question....
Your IV-9 vfd board, will it work with IV-11 tubes?
What I thought was IV-6 tubes were IV-11s, so I was happily building your IV-3a/IV-6 board, and was about to try and install the tubes and the gap in the pin legs was in the wrong place.
So thinking something must be wrong I googled IV tubes and found out that the IV-11 has the gap at about the 2o’clock position and the IV-6 has it at about the 7o’ clock position.
As your IV-9 board has them is this position, will Iv-11 ones work on this board??
So could I still use the IV-11 tubes I have on the IV-6 board and just change the pin layout to match the tube and board?
Or is the voltage requirements to different to do that?
If not I will just have to order some IV-6’s and make another clock to use up the IV-11’s I have.
who said you can’t have enough clocks!!
Thanks for the reply.
you can't simply swap Numitrons with VFDs for several reasons:
- The most obvious difference are the operating voltages: Numitrons work with ~3..5V while VFDs require ~25..70V depending on the tube type and operating mode.
- The current requirements differ extremely: Numitrons require ~20mA/Segment while smaller VFDs need ~0.5..2mA (some giant VFDs require up to 20mA/Segment)
- VFDs have a heating operating at low voltage of ~0.6..6V depending on the size and type of tube.
- Modern VFDs have a control gate which is required for multiplexing, Numitrons don't have
If you want to go for VFD - I have a beautiful VFD clock project with old, direct driven VFDs without control gates. It's not exactly cheap but some of the forum members already own it. There should have been a feature and test online here for around two years but still isn't...
Great information, thanks for explaining it so easy.
That completely make sense. I thought as they were all in the IV family, they would be interchangeable!!
So thinking about the Iv-6 board I have from Ian, would IV-11’s work on that board if I changed the pin outs to the tubes, as these are both vfd tubes?
It seems to me that the cathode and anodes both have the same voltage (1.5v and 25v)
Iv-11 have pins 1,11 for cathode, pin 2 for the grid, and pins 3-10 for the anode.
Whereas IV-6 has 7,8 for the filament, pin 9 for the grid, 1-6,10,11 pins for the rest.
So can I swap the pin outs around and run iV-11 from this IV-6 board.
Hope that all makes sense, thanks for your patience!!
are you sure that both tube types use the same filament voltage? I found some info stating 0.85V..1.15V for the IV-6. The filament voltage is very delicate - a too high voltage can destroy the tubes very quickly and a slightly too high voltage will accelerate the ageing significantly.
The most important thing is to assign the filaments correctly. the operating voltages of the grid and the segments normally are the same, so depending on the circuitry and the software structure you can easily swap the segments and grids as you like as long as you can change the software accordingly. This is what I had to do for the prototype of my UCLK project because a bug in Altium rooms caused an unwanted rotation of the tube sockets so I had to patch the prototype PCB. I made my patches as minimalistic as possible and just fixed the filament positions and changed the segment mapping table accordingly for the prototype.