Nyet!!! Monster Soviet Vacuum Florescent Display Tubes!!
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- Oh, the Humanity! Weeks in the planning, and I am going to fire up these HUGE VFD tubes - the largest 7-segment vacuum florescent tubes in the world, so far as I know. Enjoy!
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Hello there. It is actually recomended to pull anodes to about -0.3 ~ -1V to turn them complitely off.
Hopefully she sees this!
Having had experience of the russian VFDs, the anodes may even need to be pulled as far as -15V to get a proper switch-off.
I seem to recall that the heater was run from a centre-tapped secondary, and the centre was pulled to -1.5V to get the display even.
That was my first thought as well.
That is not only recommended, it's a must. Otherwise this ghosting is unavoidable, when multiplexing it's even more visible.
So that's why my CD40xx based driver was ghosting, I suspected that something was wrong._
I have the same displays and they work fine if you center tap the AC filament voltage and have pull down resistors on the segments to a negative voltage
someome else mentioned the negative voltage too.
i think thistube deserves a whole nother in depth video.
cool beans.
non isolated heater,
bottom edge of heater is 5v higher than top of heater and its acting like a drive
In fact it should be lower - heater is cathode, not anode.
@@xsc1000
i didnt see how she hooked it up, but i still suspect its not ac and isolated
With all due respect, Fran, you're trying to use some cheap third party electronic circuits with this tube and you are quick to assume that the tube is low quality. I have lived in the Soviet Union and we were surrounded by all kinds of soviet made electronic clocks installed at factories, airports, train and metro stations and they all worked just fine with proper soviet electronics inside.
try a small reverse voltage on the off segments, also do the off segments still glow if they are left open circuit?
run the heater from an isolated supply
The display is probably better with relays? You could use transistors on the first level, controlling relays on the second level.
I'd say to ground the OFF segments properly.
You can't run the heater from an isolated supply, because the heater is the electron source. Without a potential difference between the heater and the segments, they won't light, because there is no acceleration force on the electron cloud.
The heater AC supply should be grounded at the transformer centre tap so that each end of the filament alternates between +2.5 and -2.5V relative to ground. If it's grounded at just one end, the other end will alternate +/-5V, which may cause uneven brightness or segments to light when they shouldn't
@@g0hjq exactly what I was thinking.
Are you actively driving the segments positive to turn them off, or just grounding them to turn them on ?
i second this, theres current going somewhere to make those glow. there could be leakage from the perfboard or solder flux as well
Isn’t that logic for Nixie? I think VFD is positive grid and segments for on, and negative voltage for segment off.
I agree... these VFDs are alot like driving IGBTs and MOSFETs in which the gates must be pulled in both directions ... and never left floating.
Had the same issue when I got some soviet vfd-s, pullup resistors fixed it. Also running at too high pwm/switching frequency causes weird effects.
yes, I was going to say the same, off segments shorted to grid
Even though this didn't go to plan; I think they are still kinda pretty.
Hey, don't give up just yet! Perhaps some clever biasing of the off segments could do the trick, perhaps driving them negative with regards to the filament?
Also you can have a four digit clock, even though six digits are cooler, you can make do.
The wonderful thing about vacuum tubes: If they don't want to work at the specified voltages you can MAKE them work at alternate voltages. At least for a while...
Some quick research turns up that some VFDs are made with a height gradient because the filaments are supposed to be run on DC.
There are lots of great comments about negative for off segments and the gradient being intentional for using DC for the filaments. These are strange/quirky displays and probably do require strange/quirky circuits to drive them. Run your tests first in a quick messy way to prove the concepts before building your final circuit board.
Segments should never be floating.
why?
Are you grounding the center tap of the AC heater supply ? looks like you have DC across the heater. This will cause it to be brighter at one end.
I think she tried both AC and DC.
DC across the heater is bad. Grounding the center tap removes any differential caused by the bias supply across the heater resistance.
It seems like it. Hope she see it
Try one of those two things: 1) decrease the grid voltage + increase the segment voltage instead, or 2) apply negative voltage to a segment in respect to grid and see if it shuts off.
As others have said, negative bias to turn segments off. Also try turning one segment on at a time. I don’t know if you can tie all the same segments together between digits and controlling each digit by changing cathode voltage. You could control all six digits with 13 lines.
I’ve seen similar circuits and code for LED displays. The main difference would be going from positive to negative bias instead from high to low on each pin.
The code would cycle through each of the seven segments turning on the cathode for each digit that wanted to light that segment.
just to cut down on the variables, did you try driving one seg at a time with just power supplies and alligator clips?
How did you wire up the filament?
It should be driven with a center tapped transformer. The filament should be biased above ground by about 5-10 volts by connecting a zener diode between the center tap and ground.
Definitely need the filament voltage to be grounded at a center tap to stop the ghosting. For really small VFD you can sometimes ground one end of the filament. On some of the really big displays you not only need to have the filament voltage using a center tap, but you might have to float the center tap a few volts positive.
Think you need a center tap transformer to bias the cathode. Verify the cut-off voltage for the bias. This is easy to correct with a zener diode.
It can be better because of lower voltage difference on the heater ends. But I think if the transformer is insulated from the rest of the circuit and you apply cathode voltage by resistors to both ends of the heater, it should work too. Heater impedance is much lower (its wire) than A-K and G-K impedance. I would also try to put grid voltage lower in OFF mode, not to ground, but to about -5V. It can be also done just by putting cathode to the +5V level.
Чем больше дисплей, тем сложнее в производстве он и тем больше проблем с ним. Это классика, особенно в советском союзе. Например, дисплей ГИП-10000 имел еще более серьезные проблемы, чем этот ИЛЦ1-1\7.
Than bigger the display than it more complex to fabricate and it have more issues. It's classics, especially in the Soviet Union. For example the GDCCI-10K(GIP-10000) had even more serious issues than that ILC1-1\7. But you doing very nice. Really. Well done comrad, Fran. Keep doing something interesting stuff next. That's goddamn cool and interesting. Also thanks for inspiring, now I wanna made my smaller ILC clocks. (and sorry for my eng, hehe)
Tube may be a bit gassy. Also might need to drive the grid negative to fully turn off display.
Try driving the display with complementary mosfets, one to connect to B+ when ON and one to pull to ground when OFF.
Why not use shift registers and PWM the OE for brightness control. Saves a bunch of pins, infinitely expandable and with a little bit of extra code just as easy to use as digitalwrites. I’ve made a large clock using LED strips (3 die plastic encased modules) for each segment, to drive them I have them wired common anode and using ULN2003’s, CD4511’s and a shift register per 2 digits, 6 digits and 8 additional LEDs for status indicators and the colons.
As for the segments on that VFD, you may have to bias some or all of the segments or the heater possibly with a negative voltage
You can try that with your version.
FYI - The VFD displays that I have worked with suggest that the filament is powered by a center tapped secondary and the center tap is grounded. If you ground one of the filament pins to ground, you end up with uneven illumination.
I would love to see the calculator the Soviets used those in!
I was going to bring up bias voltages, but the comments already explained it better than I could have LOL.
I think you are driving it wrong, try a VFD driver (from like NEC or similar)
@Fran Blanche I suspect the ghost illumination is from feedback through the other segments due to the transistor outputs being floating, try a hard turn off by tying them to the same common supply rail through a second set of transistors.
Hey Fran! I remember that the VFD tubes needs a negative voltage on the grid to turn segments off. Furthermore why don't you use SOCKETS to quickly diconnect-reconnect them?
Or at least some short wires tacked onto the leads, which would make swapping in/out a lot easier than the proto board plated hole system.
For an "off" , there needs to be reversed polarity, i.e. Grid should be negavive voltage compared to Kathode. The negative electrical field will block the flow of electrons, like a GAIT. Zero voltage isn't enough. Just my 2 cents.
*Edit* N.B. Just had another brain fart. Could the grid mesh be magneticly gauzed ? Wondering if that would effect the electric field between the grid and kathode ? If the grid is ferritic / magnetizable alloy ? If you would decide to degauze the tube, be carefull not to apply too strong a magnetic field, it might distort the delicate grid.
Thanks for sharing, stay safe.
Een Soviet Russia, Tube Flouresces You!
Now try using it as a triode for an amplifier or guitar pedal
Dang it I made a similar comment, unaware of yours, but you beat me to the punch by about 15 minutes. :)
Maybe will work as an LCD: need inverse voltages some times to work properly.
Fran not being satisfied and demanding "Obey Me" was the energy inspiration i needed for today.
I get the exact same feeling when working with legacy plc hardware
weird fetish but ok
:)
Maybe the "off" cycle for a segment shouldn't just be off, but reverse bias low voltage to clamp it below the filament's field effect voltage?
Could you drive only the filament at working voltage and measure the voltage of each segment to see how many volts are induced by field effect, then bias your "segment off" cycle to the inverse voltage...?
Better luck on the next project. That’s a bummer to put so much work into an idea to have it go south like that. But it did lead to my new favorite Fran sound bite! “Obey Me!”, lol. Lots of luck on the next one.
Week down the tubes! I see what you did there.
How are you applying the DC filament bias?, to one end of the filament? it should be via a centre tap on the AC filament supply.
Dammit!! That would have looked so cool!!!
Try moving a powerful magnet over the front and back of the display. Maybe also check the gas content?
Tubes do not work like transistors; Grid needs a negative relative to the heater, note that the heater dc voltage varies along the length of the tube. Reverse the AC to the filament and the top traces will fail to turn off proving this idea.
Old school EE trained here. Looks like one of two things: uneven getter fire, vacuum leak during mfg.
Its obvious there is contamination. Looks like u got mfg defect from QC rejects.
Disappointing. I love the 3-D effect of the design of the segments, would have loved to see what you made with them.
On the other hand, at least this video won't inspire an army of trolls to attack your channel.
Fran's Army will ever be the bigger of the twain. I can't imagine the tech that a real army of FranLab enthusiasts would bring to bear.
@@AlanCanon2222 Fran's Army will be equipped with hand-soldered and bread-boarded weapons of new old stock analog devices and unobtainium displays.
Couldn't get past little boards shaking in my face.
on 'that bidding site' two of these are going for about 840.00. Ouch!
I would have tried turning the display upside down to see if gas is settling at the bottom.
That's what they used on Sputnik, so they could read real-time flight data from Earth ...
with these big plates you need to negatively bias the anodes to turn them off.
as many people wrote here, your driver design is faulty !!!
Aren't you supposed to pull negative voltage to stop the ghosting? 🤔
In Soviet Russia, display segments YOU seven times!
Sounds like you got stuck with QC fails or units removed from boards for premature failure.
I think Janet Leigh is horrified at the amount of YT ads. 😉
Did you try to apply a reverse voltage to turn off the segment?
I feel like it’s a kid’s show when they want you to shout the answer at the tv. “The voltmeter is doing it. It’s grounding the segments it’s connected to.”
You have to have the filament voltage center tapped to the cathode voltage. If you don't one end of the filament will have a higher voltage to the anode creating dark on one end and bright on the other. Also the open collector drivers are allowing the leakage glow. A totem pole drive will force the segments off.
I know a lot about driving these displays from the way they are used in VCR's. There 3 voltage points to hit plus the filament current drive.
Haven't hear ATMEL repeated like that since I worked there.
Love your videos on anything electronic and glowy! Fascinating.
Is it possible to put a little negative voltage on the segments that should be off to stop the bleedover? Maybe it's a common, negative, positive thing.
Lesson learned... don't make big plans requiring Soviet technology...
Try reverse biasing them, ever so slightly?
Can you shift the grid with a thump?
Maybe are design to be used upside down, or with a smoked glass filter?
I mean, still impressive.. despite everything.
Here are two thing that you can to to fix those problems. 1.) You need to power the heater on a "Center-tapped" transformer. Connect the two outside leads of the transformer to the heater and "USE THE CENTER TAP LEAD OF THE TRANSFORMER FOR YOUR CATHODE CONNECTION, VERY IMPORTANT!!!! DO NOT CONNECT THE CATHODE DIRECTLY TO ETHER OF THE LEADS GOING TO THE HEATER". Doing this should take care of the uneven glow of the display. 2.) To take care of the "glowing while off" problem. You need to actively pull the anode connections to ground.(You may also need to apply a negative voltage as well.) If you just let the anode inputs float, you will get that parasitic glow because of a capacitive charge left behind on the anode.
Regardless of the planned aim, the work of art (tube) was so incredible to view, and actually see operating :-)
amazing tech even if they act funky. Love the fact you can break down how these work
You don't own Soviet 7 Seg displays, Soviet 7 Seg displays own you comrade. (Sorry bad pun)
Maybe try DC for the filament?
ENORMOUS and works of art. Form and function comin’ at cha! But then the crushing agony of mediocrity….Even if the grid is bleeding…still pretty. can’t wait to see the other 5
Fran, I believe you should build the clock anyway - despite the wonky appearance when operating. It's still gonna look really cool. Consider the historical value and backstory. This set of poorly operating giant (post-Soviet-era) VFD tubes somehow managed to get through production despite the collapse of the USSR. Of course they're wonky!
Can you share the schematic you're using? Then it'd be possible to think about what could be causing this. It could of course be a dodgy tube, but the tube design itself seems OK, there's plenty of videos of this tube working just fine (search for илц1-1/7).
Can't help but imagine a Frankenstein's clock with all manner of mismatched VFs, nixies, 7-segment LED, and whatever else comes out of the woodwork. While innocently telling the time, the casual observer might mistake it for some mad scientist's countdown clock to armageddon.
Fran, try cleaning your driver board from flux, I had a similar problem with my IV-22 VFD clock. The segments draw so little current that a voltage next to a pin can supply enough current to the next pin on the driver board. I was able to increase the isolation between each pin, and the ghosting segments was solved. Worth a quick try!
Having grown up in USSR I have seen these massive VFD 7 segment displays everywhere (schools, factories, etc). They were usually mounted in hallways to show the time, temperature and shift/class details. They were bright and clear (no ghosting segments). Perhaps they need negative bias on the segments to turn them off?
Watching you solder despite your essential tremor is exemplary of "don't let your disabilities stop you'... A reminder I need these days, too.
As for the I.L.T 1/7? interesting to see it, and how poor the manufacture was. However, an idea struck me: Pulsing the grid timed to individual elements? Only a hassle and high current transistor...
I've been playing with esp chips for my iot junk, but 50-x digital + 16 analog? I have chosen the wrong tech for my jobs. :-/
Very interesting - never seen a VFD that huge before.
But it being made in Ukraine reminds me of an incident when I was working in electronics for the Navy in the 1980's. Someone had noticed that some of the vacuum tubes we had in stock were manufactured in Soviet Bloc countries. I had to go unreasonably high up the chain of command to convince them that:
1. They had actually been purchased by the Department of Defense on competitive contracts.
2. Those tube types were no longer being manufactured in the USA or any allied countries
3. The electrons don't give a damn about geo-politics. All the electrons care about is seeking a higher potential and thereby making the equipment work.
4. No I cannot jigger a different type of tube to make the equipment work, and
5. I need to get back to work, put these "communist" tubes in the equipment, finish the repair and calibration, and send it back to the owning ship that is deploying tomorrow!
can you give us a simple circulate drawing for us to understand more for each time.the second is that can lower your camera for us to see somethings clearly.we are more interesting in many of them,thanks.
I think I heard you say initial power was AC. I wonder if 50 Hertz vs 60 Hertz would make a difference?
This is a sad reality of parts from both former USSR and China. If you are used to North American, European, Korean, Taiwanese, Japanese or AsiaPac JV parts this can come as a surprise ! I often buy lots from different sellers to get working ones even with recently manufactured parts. I think QA is often done "soviet style" (ie not at all) - parts are churned out and just tested on the fly during final assembly process into devices. You might also find those were the lots were only made to meet some silly 5 years plan target, likely never to be used, and QA just not a thing even considered.
If you've ever watched Russian Dash Cam videos, their drivers often say "Blyat!" Around the time of an impact.
Showed the video to someone from Russia who has a side job recovering Russian VFDs. He said "incorrect filament power supply, there is no "midpoint" on the wire and it must be AC." Not sure if he's right though.
Part of me wants to find one of these suckers & a datasheet and mess with it: This smells like something that might be able to be resolved with "clever" biasing tricks. ("If I can make an EF86 operate as an RF mixer with variable gain I should be able to bend a simple VFD to my will!")
The other part of me has 6 projects on my bench and knows I have no room for this no matter how damn cool it is.
1. The tube being demonstrated is faulty.
2. The segments each require different levels of voltage / current and require more distinctive (?) power.
Hopefully you can recover your money for the bad tubes or get replacements?
these tubes (indicators) are actually made just for wall mounted clocks ) (and that's why they are so cheaply made. usually they work ok but they are very fragile so yours must be damaged)
another iconic russian clock tube is "ИВ-26" which are long thin tubes with one row of 7 round dots (spacing between dots within one tube is equal to spacing between similar dots in separate tubes put next to each other). those tubes are made for combining them in 7xN dot matrix.
IDK but use ziner 😣 diodes for each segment?? But it is possible to hand craft some BIG vaccu-florescent tubes
Could be props from 'the Forbin Project' - Guardians clock :)
I wonder if there's a transparent conductor that can hold up to a Neon discharge. I think a hybrid of Nixie and VFD that's fully transparent would be really cool!
I'm in the digital clock industry. I want those!!! Hey google!!
Hi Fran. Been watching you for a while now,am subscribed since the beginning. Wondering if you can work on tube linear amplifiers for Ham or CB band. Please let me know if your interested in this work.
Think little bit harder ! I hove seen them working perfectly . They made them knowing they don’t work ? How did you get so smart ? Just being born in America ?
Could you clarify: Is the direct-heated cathode AC or DC? If the latter then the accelerating cathode-anode pd would vary along the cathode length and would produce a variation in brightness. (The top looks +ve compared with bottom).
Are you biasing the anode on directly by a transistor? I would bias the anode on by an anode load resistor and shunt that to earth (I understand A Merkins call that ground) with a transistor.
I'd try varying the anode and grid biasing to ensure offness when desired. I had originally considered the problem to be due to space charge, but the phosphors I have used are not as sensitive as that displayed, so I have deconvinced myself.
The low cathode-anode pd means that the device is susceptible to electromagnetic fields on the loose, such as from wallwarts and other lab equipment. Kit I have that uses such devices has fine faraday cages around or in front of the displays.
Anyone else remember the 1990s Macintosh Melting Clock? Was that After Dark (tm) ?
Fran... Fade up the next numeral segments, fade down the previous numeral segments.
PS: Ask your Russian fans if those things ever worked right.
I built a 6-digit clock using the smaller version of these tubes from a Ukraine seller, and they all worked fine. I suspect the problem is partly how the tubes are being driven - they are rather finicky.
Some dark glass, or foil might surpress the light coming through. And some calibrated tuned PWM values per segment might make it an evenly lit when segment is on.
I wonder if turning the first display upside down changed the evenness (maybe the grid is loose and is affected by gravity)?
Maybe if you drive this as a tri-state device? High, low, or open? Might greatly reduce the glow. Thinking tristate sort of the way old Commodores used to run the bus lines.
Hm.... toob two..... reject again.
Yup, factory rejects!
Soviet precision at its best. Don't get me wrong, they were able to make great precision stuff, but if the wrong comrade got too high position and horned into the production and/or design, things like this usually happened. A huge tube like this should be easier to manufacture than the smaller ones, and they were able to make tiny ones reliably. Here they just used blobs of resin for spacing the grid from the backplane. No wonder the distance is uneven. And using an evaporated trace for the filament current is probably a design flaw, such a huge tube with all filaments in parallel has some substantial heater current, a super thin, vacuum deposited trace seems inadequate for handling it. It should be a metal strip or at least a thick film printed trace. The vacuum deposited traces are fine for the segments, but not for the high current of the heater.
Fantastic..allways wanted too see these displays/ lite up..GreatJob...BeHappy😃
Could you possible. instead of turning V- on and off to light up a segment. Flip flop them from V+ to V-. Forcing the segment off that way?
I would guess that the traces all bunched together and the closeness of the grid in the bottom left-hand corner means that this whole corner never really turns off.
.
Nyet, VFD is not fine.
I think you could make some pretty authentic looking ones with electroluminescent segments. It would take some work though
High impedance on anodes, capacitive coupling from filament takes them positive so they turn on where the grid is closer. Also filament power should be effectively centre tapped, and then you need to make sure the off anodes are more negative than the filament at all times .. perhaps connect filament ' centre tap' to a positive supply.