Thanks man! May I ask, somehow I got to see you start building the Koolklox I think. I am not sure how I got there. I feel that I am going crazy...I think I started to watch one and was going to come back... That video or those videos are not in your video list. Are they private? Just curious. Hope all is well.
@@RollingTardis yeah, that is inevitable with me. Some are good rolling along. If you watch my clocks count while I talk, you can see what looks like seconds that mis count....that is me cutting blunders and ummm's and ahhh's.
Nice work so far! I'm looking forward to seeing how this one turns out. VFD clock transformers sure are hard to find, you pretty much have to get them out of an existing clock it seems.
I even tried a few calculators...did not find what I was looking for in a transformer. Spoiler...I am swapping one of the transformers out in the next day or so...I need a little more "punch" on one of the supply rails....the next vid should be good.
Hi Jim, very nice project and video, thanks for posting. Also, I commend your attention to testing at each stage and being very methodical! I do have one question/observation which I'm curious about your thoughts on. It has to do with biasing the filament slightly above ground. The reason for doing that is to create potential with respect to the filament when the grid/anodes are off in order to prevent "ghosting". The Noritake document discusses this and I've included an excerpt below. Oftentimes, a zener diode is used to between the filament and ground to produce this bias. I do realize that your brightness control resistors may have that effect, although it's more of a side effect than and any bias would vary based on the Hi/Low setting. I don't know if that is intentional in the design or not. Also, i do realize that this is a published schematic that is presumably known to work. But as I said, just curious about any thoughts you might have on this topic. Below is the excerpt from the Noritake document (which is available as a pdf if you search for it). Thanks and looking forward to part II! 6.2 Filament Bias Voltages (Ek) The filament bias voltage (Ek) is a voltage applied to the filament center-tap in order to cut off background illumination when the anodes and grids are not addressed. The 'off' anode and grid voltages remain negative with respect to the filament. The total supply voltage Vdisp is ec(eb) + Ek. ( In the case of CIG displays, the Ek is included in VDD2.) In typical driving circuits, a zener diode supplies the Ek as shown in Fig.17. The cathode bias (Ek) for filament center-tap is higher than that specified for the grid cut-off voltage (Ecco). Usually, the Ek is set at the same value as MIN voltage of Ecco shown in the specification or a slightly large value when utilizing a filament center tap (F.C.T.). If a center-tap is not available, a virtual center-tap with resistors is one acceptable alternative.
Thank you for the reply and information. To start, I only have a slight idea on how the science in this reference connection works. It is mainly from playing with a few clocks on hand. For example, I added in a resistor where the was a direct connection to ground from the AC filament circuit on my big Elektronika (see that video) solely for the purpose of dimming. I think I saw this on another clock I have, I can't remember if that is where I got the idea from or if the idea was from the Archerkit schematic used here. Building this clock, we all saw the ghosting pop up bad if I got the bias too close to ground. I never saw that before this project. I am not sure why that is. The big Elektronika did not have this issue but it may not be multiplexed now thinking...not sure. That would explain that. I did try a diode in there with the resistor figuring AC was leaking across, but I only tried it in one direction..hmmm. It was a simple rectifier diode. I also can say, the MM5314N and even the MK50250 are known for ghosting on displays. I have found a possible improvement on the 1985 vintage version on the mm5314 in comparison to the older ones. I do not know enough to comment on if any or all multiplexing has these issues. With modern programmable IC's, timing adjustments could be made I guess. As far as your reference...May I ask what the Noritake document is in relation to? Can you link it here? I am not sure I can follow the excerpt alone. I may need a schematic to see how it is layed out to even try. Thanks again.
@@JIMO415 I don't believe that youtube allows subscribers to post links to another channel so I've sent you an email with the document link and some additional information. I believe that "ghosting" can occur regardless of direct drive, or multiplexing since it has more to do with biasing the filament voltage with respect to the grids/anodes voltage such that when the grid/anode is "off", it is forced to be "hard off". It could be though that multiplexing exacerbates the problem due to the sudden switching and reduced settling time. You may or may not have an issue with "ghosting" for your VFD clocks, but if you do, the information I sent may help with that.
@@Enigma758 I got it, thanks. I scanned thru it quick and it looks informative. I will study it when I feel "clear minded". I did look at 6.2 and you may have noticed that I did use a center tap transformer for the filaments. That will give me something to also play with. thanks again!
@Enigma758 Thanks again for this document: www.tayloredge.com/reference/Electronics/Displays/VFD.pdf - It has alot of good information, all in one spot. Apparently, I have picked up on some of that info along my journey, mostly in forums and discussion and from playing. For example ac on the filaments is better for luminosity, interdigit blanking on driving signals for ghosting control and more. Getting things explained better is great. In getting into 6.2 in the doc, I have a little better understanding of one of the segments that will be in my next video update on this project. I adjust the filament bias as the display is running and can see a point in which ghosting comes in as I approach the ground potential. Creating more separation corrects this. Having the "off" anode and grid more negative than the filament is what we are trying to achieve to help with ghosting. Now, the use of a resistor vs a zener for this purpose is not explained and at this point, I do not have anything to offer on that. I may have to get my hands on a few different zeners and play with that bias. A resistor does get a voltage drop across it. Measuring the voltage drop across the "everything happy" reference resistor I selected (in next video) may be a thing to try to start with. All in all, the next video will show alot. Maybe I can experiment a bit if my stamina at the bench allows. Also to mention again, the inter digit blanking (section 4.2) was something I knew a little about. It was nice to have a better explanation of what is really going on as it pertains to VFD's, drivers and internal stray capacitance.
@@JIMO415 I'm glad you found it helpful. As I mentioned before, you may not have any issues at all with the ghosting, but if you do, the document provides some guidance to experiment with which it sounds like you have begun doing. It might be nice to see the actual AC waveform on a scope. It could be that your dimming resistors are providing sufficent bias, hard to say. In any case, looking forward to seeing the finished clock!
Thanks. This was on my want to do list. I wanted to build up this circuit to be the only one who is driving the IV-11 with an MM5314! I already have a MM5314 driving an IV-18, so what why not, right? Besides, I do not have to translate data sheets this way LOL. Just wait until I make a single digit nixie clock with the huge ZIN-70 run off of a mm5314! I gave away the Chinese clock base for it already...no interest in that. I have to do it my way as they say. As far as the IV-11 anode voltage, yes 25 to 30 volts but if multiplexed (pulsed), 50 to 70 volts is on the datasheet.
Looking Good! Can not wait to see it lit up!
Thanks man! May I ask, somehow I got to see you start building the Koolklox I think. I am not sure how I got there. I feel that I am going crazy...I think I started to watch one and was going to come back... That video or those videos are not in your video list. Are they private? Just curious. Hope all is well.
@@JIMO415 All the KoolKlox videos, are in the LIVE section of the channel page
@@RollingTardis wow, ok thanks. I am not crazy. I don't have a live section....probably because I never did a live video! LOL
@@JIMO415 Hard to hide blunders on a live stream. I had a few on the clock build.
@@RollingTardis yeah, that is inevitable with me. Some are good rolling along. If you watch my clocks count while I talk, you can see what looks like seconds that mis count....that is me cutting blunders and ummm's and ahhh's.
Nice build. I like the repurposed case wood box!
Thx for good content from Palermo, Sicily - subscribed
Hello from the USA. Thanks for the complement!
Cool stuff
Thanks!
Nice work so far! I'm looking forward to seeing how this one turns out. VFD clock transformers sure are hard to find, you pretty much have to get them out of an existing clock it seems.
I even tried a few calculators...did not find what I was looking for in a transformer. Spoiler...I am swapping one of the transformers out in the next day or so...I need a little more "punch" on one of the supply rails....the next vid should be good.
Hi Jim, very nice project and video, thanks for posting. Also, I commend your attention to testing at each stage and being very methodical!
I do have one question/observation which I'm curious about your thoughts on. It has to do with biasing the filament slightly above ground. The reason for doing that is to create potential with respect to the filament when the grid/anodes are off in order to prevent "ghosting". The Noritake document discusses this and I've included an excerpt below. Oftentimes, a zener diode is used to between the filament and ground to produce this bias. I do realize that your brightness control resistors may have that effect, although it's more of a side effect than and any bias would vary based on the Hi/Low setting. I don't know if that is intentional in the design or not. Also, i do realize that this is a published schematic that is presumably known to work. But as I said, just curious about any thoughts you might have on this topic. Below is the excerpt from the Noritake document (which is available as a pdf if you search for it). Thanks and looking forward to part II!
6.2 Filament Bias Voltages (Ek)
The filament bias voltage (Ek) is a voltage applied to
the filament center-tap in order to cut off background
illumination when the anodes and grids are not
addressed. The 'off' anode and grid voltages remain
negative with respect to the filament. The total supply
voltage Vdisp is ec(eb) + Ek. ( In the case of CIG
displays, the Ek is included in VDD2.)
In typical driving circuits, a zener diode supplies the
Ek as shown in Fig.17. The cathode bias (Ek) for
filament center-tap is higher than that specified for
the grid cut-off voltage (Ecco). Usually, the Ek is set
at the same value as MIN voltage of Ecco shown in
the specification or a slightly large value when
utilizing a filament center tap (F.C.T.). If a center-tap
is not available, a virtual center-tap with resistors is
one acceptable alternative.
Thank you for the reply and information. To start, I only have a slight idea on how the science in this reference connection works. It is mainly from playing with a few clocks on hand. For example, I added in a resistor where the was a direct connection to ground from the AC filament circuit on my big Elektronika (see that video) solely for the purpose of dimming. I think I saw this on another clock I have, I can't remember if that is where I got the idea from or if the idea was from the Archerkit schematic used here. Building this clock, we all saw the ghosting pop up bad if I got the bias too close to ground. I never saw that before this project. I am not sure why that is. The big Elektronika did not have this issue but it may not be multiplexed now thinking...not sure. That would explain that. I did try a diode in there with the resistor figuring AC was leaking across, but I only tried it in one direction..hmmm. It was a simple rectifier diode. I also can say, the MM5314N and even the MK50250 are known for ghosting on displays. I have found a possible improvement on the 1985 vintage version on the mm5314 in comparison to the older ones. I do not know enough to comment on if any or all multiplexing has these issues. With modern programmable IC's, timing adjustments could be made I guess. As far as your reference...May I ask what the Noritake document is in relation to? Can you link it here? I am not sure I can follow the excerpt alone. I may need a schematic to see how it is layed out to even try. Thanks again.
@@JIMO415 I don't believe that youtube allows subscribers to post links to another channel so I've sent you an email with the document link and some additional information. I believe that "ghosting" can occur regardless of direct drive, or multiplexing since it has more to do with biasing the filament voltage with respect to the grids/anodes voltage such that when the grid/anode is "off", it is forced to be "hard off". It could be though that multiplexing exacerbates the problem due to the sudden switching and reduced settling time. You may or may not have an issue with "ghosting" for your VFD clocks, but if you do, the information I sent may help with that.
@@Enigma758 I got it, thanks. I scanned thru it quick and it looks informative. I will study it when I feel "clear minded". I did look at 6.2 and you may have noticed that I did use a center tap transformer for the filaments. That will give me something to also play with. thanks again!
@Enigma758 Thanks again for this document: www.tayloredge.com/reference/Electronics/Displays/VFD.pdf - It has alot of good information, all in one spot. Apparently, I have picked up on some of that info along my journey, mostly in forums and discussion and from playing. For example ac on the filaments is better for luminosity, interdigit blanking on driving signals for ghosting control and more. Getting things explained better is great. In getting into 6.2 in the doc, I have a little better understanding of one of the segments that will be in my next video update on this project. I adjust the filament bias as the display is running and can see a point in which ghosting comes in as I approach the ground potential. Creating more separation corrects this. Having the "off" anode and grid more negative than the filament is what we are trying to achieve to help with ghosting. Now, the use of a resistor vs a zener for this purpose is not explained and at this point, I do not have anything to offer on that. I may have to get my hands on a few different zeners and play with that bias. A resistor does get a voltage drop across it. Measuring the voltage drop across the "everything happy" reference resistor I selected (in next video) may be a thing to try to start with. All in all, the next video will show alot. Maybe I can experiment a bit if my stamina at the bench allows. Also to mention again, the inter digit blanking (section 4.2) was something I knew a little about. It was nice to have a better explanation of what is really going on as it pertains to VFD's, drivers and internal stray capacitance.
@@JIMO415 I'm glad you found it helpful. As I mentioned before, you may not have any issues at all with the ghosting, but if you do, the document provides some guidance to experiment with which it sounds like you have begun doing. It might be nice to see the actual AC waveform on a scope. It could be that your dimming resistors are providing sufficent bias, hard to say. In any case, looking forward to seeing the finished clock!
The IV-11 tubes are usually driven by 27V on the anode.
Man, why did you have not dropped me a line?
Thanks. This was on my want to do list. I wanted to build up this circuit to be the only one who is driving the IV-11 with an MM5314! I already have a MM5314 driving an IV-18, so what why not, right? Besides, I do not have to translate data sheets this way LOL. Just wait until I make a single digit nixie clock with the huge ZIN-70 run off of a mm5314! I gave away the Chinese clock base for it already...no interest in that. I have to do it my way as they say. As far as the IV-11 anode voltage, yes 25 to 30 volts but if multiplexed (pulsed), 50 to 70 volts is on the datasheet.
OMG.
I could have sent You a pcb of the iV11 clock I have made, along with the original sovjet made KR145iK1011 clock chip.
too easy LOL