MAKING A GARGANTUAN NIXIE TUBE

this session we're gonna make something really unique crazy we're gonna make a nixie tube that is really big i mean this is not a giant nixie tube this is a gargantuan nixie ii um i got here this is gonna be the envelope it's uh i don't know how tall it is let's see it's it's eight inches in diameter and 20 inches tall that's the biggest one that i could find there's no way that i could blow a uh an envelope this size with the equipment that i've got uh these are molded these big this is a cloche it's a uh made for like putting plants or uh things that you don't want to get dust on yeah and these are molded they're they're molded and they're not particularly expensive they're under a hundred dollars on ebay and this is going to make the envelope now to make a nixie this big we cannot do it in the conventional way an envelope this large would have to be in order to support a vacuum that we it would take to have a real nixie tube conventional design would have to have glass that was a half inch thick to be safe you know this thing here this is paper thin this this glass is it measures about a sixteenth of an inch thick it's very very thin so it's just decorative you could not put a vacuum in here and expect it to hold up if you got it pumped down it would be a really dangerous fun thing to like throw something at it and let it explode and it would explode literally implode explode same thing when you have that kind of pressure okay now for the letters we're going to make them in the same way that neon tubes are made we cannot have the conventional design of nixie with all the whole envelope filled with a vacuum nick uh neon under a vacuum there are a couple of different problems doing that even if we had a an envelope that would take it the pressure the problem comes from electrical problems when you've got huge distances between the parts of the number and the uh in the anode there's all kinds of problems that crop up you'll have part of the electrode will light up and if everything isn't spaced absolutely perfectly then the the glow will concentrate there and you'll have to run so much current through it to get it to light up the rest of the number that you it would be ridiculous the thing would turn red hot it would be so much current so that kind of a situation simply cannot be um cannot be done you know dalibor is making some that are oh you know about so big around and he's somehow he's getting it to where the uh the the glow on the tube is spreading out evenly so it should work but trying to do it on something when you've got a number this big this is the size of the numbers that's going to be in there that's uh i think 14 inches is what i figured yeah okay 13 inches tall numbers are going to be 13 inches tall inside there and there will be 10 of them and they're going to be made out of this capillary tubing and this will be uh filled with neon and sealed off with electrode in each end and just exactly like neon sign we'll just take it and bend it you'll bend the tubing into the shape of the number and at the bottom we'll just have two ends and we'll have the two electrodes and we'll go ahead and hide them so that they don't show up when you like like the nixie and that will give us a glowing number and we'll have the ten numbers set in there and um it will work just like an a real nixie tube now the very bottom see this will the the numbers will go to here so we'll have about four inches in the bottom and that's where the high voltage power supply will be placed uh these take about 1100 volts i tried a uh a 13 inch tall one which i have somewhere see if i can find it okay here i have a 13 inch long two which will be similar to the number one and you can see it glows really nice really nice glow to it i don't know doesn't really look that's that's what it looks like right there that's what it looks like okay so that's the glow that we get out of it now it takes a bit of for this one here alone it takes about a thousand volts to break it down and get it to get it to arc so it's going to take some very high voltage drivers to drive the tubes i haven't yet decided exactly which scheme is going to be ideal for driving it obviously using uh transistors is not going to be valid using a single power supply and transistors there are some high voltage transistors out there that will handle oh 1200 volts maybe even 15 100 volts but the thousands of volts like the number eight requires a one meter that's one meter of glass tubing this is going to take on the order of 5000 volts to break down so so controlling 5000 volts with the transistor itself is not going to be practical it would take a string of them connected in series that's getting too messy so what i'll probably do is make individual inverters for each number i'll have 10 inverters and the inverters will be controlled with a low voltage say 12 volts and then the output of the inverter will be the thousands of volts this serves two things the first thing we want ac on these on these uh tubes we don't want to use dc to light them up so we're going to use ac just like in a neon sign to light up the tube and an inverter a small inverter that'll put out the the uh 5 or 10 milliamps that it takes at the 5000 volts this will not be much it'll be a little small inverter that can be easily built and there'll be 10 of them to one for each digit and those will be easily switchable by the 12 volts on the primary of the inverter okay the first thing that i'm going to do is to make up the numbers the uh the envelope is already made bought that i got that uh from an antique shop here in town for uh 50 bucks so that was no problem i just have to make sure that i don't break it as a matter of fact i'm going to go put that somewhere out of sight so it doesn't get broken okay now what we have to do is determine how long of a glass tube we need for each number i've gone ahead and laid out the numbers one-to-one size on the paper here just by using drafting techniques okay so what i'll do is i'll just bend this wire roughly to the shape all right so that's going to be the length we need for a number two okay here a piece of glass okay i've got another piece here okay this piece here will do good for a number two and get it off there easily okay that's number two okay that's our piece of glass for number two set that aside okay okay let's just go with a uh a number two for the heck of it okay two will be like that and then this end we're just going to seal an electrode in on the bottom end where we're going to put the connections we're going to have a t which is a fill tube this would be tubing of course sort of more or less like this okay we'll have this one being the seal for the electrode and this side tube is where we'll connect it to the vacuum system to go ahead and fill it and then we'll heat it there and that'll seal it off okay so what we have to do on each piece of tube we have to start off with a long piece of tube and we put the side tube we go ahead and seal that side tube onto there now working with tubing this small is no piece of cake this is it's much more difficult working with this small tubing than it is with something quarter inch or bigger i mean if this one little bit of extra heat and it seals it off it just immediately closes up from surface tension so we have to be very careful when we're doing these um these side things or else we're going to ruin each piece of glass all right let's get that glass work done all right problems have cropped up i have found that doing the glass work on this 1 8 inch tubing is too tedious it's very difficult to keep the glass from collapsing when i'm going to make these side joints so i'm going to go ahead and increase the size of the elements the um the numbers to a quarter inch this is eighth inch here a little bit under an eighth of an inch i'm going to increase them to a quarter inch quarter inch is a little bit easier glass to work with now the quarter inch glass see is substantially larger and easier to work with you know that we'll be able to work with that a lot easier than this little thin stuff okay so i'll have to make up a new set of uh tubes quarter inch is about as big as i can go see if i go and do 10 i'm going to just draw 10 here that's 1 2 3 9 and 10. see that's still that's going to be the thickness of the stack of numbers so in an eight inch in diameter that's still going to fit if i go much bigger than that if i try 5 16 tubing that might get so thick that we can't fit it in the um in the diameter of the envelope so this is about as big as we can go so i've got to succeed at doing the glass work on this quarter inch tubing it's the smaller the tubing is the more difficult glass work is i did a test on the quarter inch glass and it's completely practical to make the t connection that's no problem at all that's nicely made sealed easy to make so we're going to use that as our design for the number seal okay we need to make ten of these okay this one here is a number one i made this the length for a number one okay now we got to make up the rest of them okay the first thing we're gonna do is get the lengths of the tubing just like we did for the thin stuff all right that's a number two okay so i take [Music] that's for number two all right here's the side tubes that was not big deal to make those up [Music] all right the next thing we got to do we have to grind these side tubes okay we have the main tube like so and a side tube is going on to it like so so we have to we have to curve that too so that it's going to fit against the curve see if we just leave it flat we're going to have a big gap so we got to go ahead and curve those to do that we use the dremel tool with a diamond fur in it okay this burr wherever it is is the diameter of the glass tubing okay that's the same size so if we take it and we just grind into it that'll give us our curve that we need [Music] okay you see how that is okay and that'll go just right up against [Music] that tubing like that and just you know that fits perfectly okay that makes it where there's less gap it's easier to seal the glass all right we got to do all nine of them okay now that gets us all of our side tubes okay next next thing i'm gonna do is glass work we gotta blow holes each of these needs a hole blown in it so that we can um seal the side tube onto it okay so we're going to blow holes in each one of these do that using a torch okay we're going to use a different camera for that because um because the i don't have a filter i don't have a a glass filter for this one that filters out the uh the glare we go ahead and we plug the end off that we're going to be working on and the other end we need the hose now that i can put some pressure inside the tube okay what i'm going to do is i'm going to heat a spot up on the side of the tube and just blow a hole through it by using the hose i can just put some mouth pressure on it and just pop a hole okay okay oh okay let's go to the next one okay go again so okay i take care of all of the holes okay now to to put our side tubes on we have a fixture made up here and we put our main tube in this part we slip it onto this mandrel and we line it up all right we've got a fixture here we have the main tube here with the side hole in it and we have the um the stem and that's fit there we have our mandrel pushed all the way up then we have another mandrel that goes up inside and that one is arranged to rotate so that when the glass closes down on it it doesn't stick to the metal okay so what we're going to do that comes out of there due to vibration i gotta fix that okay we're gonna do go ahead and do the glass work hmm so so all right now i got to get this grant get the bottom okay that's not going to be too good on the camera but you can imagine what i'm doing down in there all right okay see how that is all right that's one of them done all right let's do another one so we've been having those mandrels in there the glass cannot collapse when we heat it okay i don't need to bother with a camera because you can't see down in there anyway okay see see how that is that nice okay see and that's a long long long one that's our number eight okay this one fits into it okay here we have our number one um we already have our glass done here and um [Music] we'll go ahead and seal electrodes into it and that will be our number one [Music] okay and stick it in there okay first thing we have to do heat up the electrode to drive the air out of it and to oxidize the tungsten and by heating it up to red like that all that cork that was on there from doing the welding is gone okay now we'll do the tungsten it puts a layer of oxide on the tungsten to make the seal all right next we'll do the seal itself move it up pinch and seals it up clean it up that looks good okay just positioning it toward the electrodes right in the middle of the tube okay that gets our two electrodes now we're going to bend the seven i've got the air hose hooked onto the uh stub here so i put pressure inside the tube to keep it from collapsing when i bend it and it marked right where the find okay all right looks like about another 10 degrees that looks perfect okay there's our number seven all right here's our number one okay bring it on down this is in tour i usually take it down until it's uh to about 10 microns or so the stage down here reads this is in in microns here okay so what we're going to do now we're going to take the torch and we're going to heat the glass to drive all the air out of it so so so okay now i'm going to go ahead and put some argon into it and run current through the tube to go ahead and heat up the electrodes i'm gonna turn off the vacuum and open up the argon okay that's about four torr we got that four tor in there right now okay putting 5000 volts on the ends of the tube what that's going to do is that arc glow discharge will heat those electrodes and drive the last of the air out of them you see it changing color because it's driving air out of it if you don't get the air out of it then the neon glow will change color it won't be the true orange it'll turn kind of a purple color sort of like this instead of being that orange the type of electrodes that you use also makes a big difference in how this tube will process if you use the wrong metal then oh my goodness you can have terrible trouble nickel and tungsten are the two good metals to use they they do the best using things like iron and aluminum or anything else oh boy we have trouble all right the pressure's not changing in it anymore so i'm going to go ahead and evacuate it again okay i've got the vacuum turned on and it goes 50 microns okay i'm going to close it put more argon what i'm doing is i'm just looking for color change as long as there's no color change we've got all the gas out of it but if it starts changing color that means there's still gas and we have to cycle it like that we drive it out into the tube and suck it out with the pump and close it off put fresh argon and do it we do that until we don't get any color change in the tube and then we know that um all of the uh the air has been driven out of the uh electrodes those suckers are really hot right now they're not quite red hot it's got 30 million this transformer is putting 30 milliamps now i don't have any resistors in it and i've got the variac turned up all the way so it's 30 milliamps driving down the tube and that's uh at 5000 volts i don't know what the voltage is across it right now it's probably 1000 volts or so so it's good 5 to 10 watts being dumped into that tube i don't see any change at all in the color all right we're ready to fill it with neon turn the pump off and open her up okay that's 1.4.5 torque that's 2.57893 point four three point six seven that's four four point five nine five four okay five torr nice orange there and we'll let it sit there and bake for a minute and just see if it changes color if it changes color we still have air in the tube and it won't be any good it's starting to shift a little towards purple the the camera i don't know how to make the camera show that uh the the the camera is saturated where the tube is so it's hard to tell what the color is okay so i'm going to waste this bit of helium i mean um neon and i'm just going to let this glow a little bit to drive any last air out and we'll put a fresh charge in it and go again all right i should do it okay let's go ahead and vacuum it vacuum is closed off open the valve 2.5 six seven nine three four five okay that's got beautiful orange glow all right we're gonna seal her off and be very careful if i overheat it it will suck through and flow through and ruin it oh it's closed off now let's stretch it and it is sealed off let's hook the voltage on to it to see if we succeeded ah it turned purple oh no oh oh what a disappointment an air what i'll do is i'll cut this off and i'll seal the tube onto it and try again otherwise we have to just make it remake it from scratch all right number seven let's try number seven okay now i want to test this joint for leaks first okay gotta preheat that one and seal it all right let's test it again okay vacuum is on sucker down no leaks okay next thing we'll heat the thing up especially when i heat this stem because that's where you get the flash of air see we're not using any getter in here so it means that the glass has to be completely free of air otherwise when we go to seal it off it'll drive the air out and poison the poison the neon that's good now all right let's put some argon in it and go again there's about four four tour of argonne we'll just let that sit there and cook okay we're gonna let that cook for about five minutes and a fellow at the sign shop neon sign shop said he processes his tubes for about 30 minutes to an hour hello those test ones i made i only process for about a minute and they're holding beautifully feed it anymore it's up to over a thousand degrees that is for sure got all the gas out of there okay that thing's degassed all right let's go ahead and put some neon in it okay i'm going to turn it down and get the vacuum pulling all the argon out of it we take it down to like 20 microns to make sure that we have every trace of argon out of there okay here goes okay valve is off and open it up and there's our neon okay that's one point three four two torr okay i put a piece of paper there you go you can see the paper see the paper that's the color the the glow really is all right i'm gonna raise the pressure right now we're sitting at at two tours i'm gonna go up to five okay open the valve okay there's three okay and that's fine now what we're measuring the pressure with here is called a baritron and you can get these off ebay they're around 50 to 100 dollars in working order this one goes from zero to 100 torr and the output scale is directly linear zero to ten volts so when it reached 10 volts then you're reading 10 i mean 100 um torque and it just divides down evenly from it these are the best way to measure vacuum there there's no other gauge that is as accurate and as precise as these barotrons made by mks company which is uh probably the best vacuum company measuring company in the in the world and the the one that we've got measuring the main system is their model 121 which is a um oh it's just it gets it it's amazing that sucker is good over four decades okay this thing is holding solid okay holding solid i'm going to cut the current the right now all of the leakage in the system is down in the bottom there there's no leakage here we know that and uh the very top we've got that pretty much sealed off but down in the bottom there is a leak and it gradually the system will come up it's got o-rings it's got valve seats and all of those leak and that's why when we turn this on we see a little bit of purple here because the gas is slowly seeping back up in and the air which is leaking in seeps up in this end so we see a little purple here whereas down at the bottom if you look here we see kind of a purple color whereas if we get here it's pure orange and as that air leaks in it'll get down to that end of the tube and it'll be uh purple too so the key to having it pure neon is we have to vacuum it down we get it completely air de-aired then we vacuum it down and then we put a fresh charge of neon in it and immediately seal the tube off we don't give it any time for that air to bleed back in there because right now that air it's purple all the way up to about here the only place that's still orange is way down at the other end and if we sealed it off right now that air would gradually just go through the whole tube making all of it purple like what happened before that on the number one now the number one i got busy and i sealed another um stem onto it so we can give it another try here in a minute i'm pretty much happy with it what i'm gonna do is make an attempt to seal it off okay the first thing we do we put some fresh neon into the uh into the line we're ready to go now i'm going to pump it down to nothing i'm going to close the valve open the neon and get it in there glowing properly at five torr and then immediately seal it off before air can leak in okay okay power is on and valve is off open the neon and it's two three four nine there we go at five okay i'm gonna seal it off right now okay close it we don't want the air to get in there okay all right let's see what happens dude will you succeed okay so still pumping down till we get down in the 20s we still have air in it okay let's see what happens okay voltage is on and valve is closed they open up the neon there we are okay point eight one two five five and a half look at that blue i am not understanding that blue okay we're seeing it stay a constant color not changing so that indicates that we are hermetic okay and the leak detector i've tested it on the leak detector and it shows no leaks so okay let's go ahead and um pump it back down okay we're in the 20 20 micron range okay i'm gonna close the vacuum valve open neon okay there we are one point sixteen that's five two we're going to put five torr that's three four gorgeous gorgeous gorgeous okay that's just a beautiful solid color we don't have any purple showing up at all so we're hermetic so that's it oh that looks gorgeous okay there we go that's our number one okay okay i need this one a little more that'll do it all right we got the four on there and we've heated it up and we're down at 20 microns so we're going to fill it up with argon first okay let me hook up the voltage to oh all right we're not getting it why don't you remember the plug to the power supply there you go i was wondering what was going on here 5000 volts ought to be enough for any of these numbers we're doing here you get some really long pieces of neon and you can end up with uh having to um have have seven thousand eight thousand volts but uh that's you know you're talking twenty feet long ooh look how red red okay i'm gonna cool it off i don't wanna do it see by heating them up red hot like that it drives out all of the air and any cork anything else that's left on there gets vaporized and carried away okay okay we'll go ahead and clean it out all right we're down about 28 microns oh okay i'm gonna close it off okay vacuum is closed off and we open up the neon valve there we are that's two torr okay we want to go to five torr four point four five i got all the electrodes and stuff put into all of the blanks so now we're ready to go on them they're all sealed and they're tested to see that they're vacuum tight so we're ready to go ahead and bend the numbers okay to bend the numbers i've got a table here that i've made up out of plane proof wire and i've got a ring here that i've fastened onto here that's the size around of the curve okay so this is made out of copper so it's not going to melt so i can't put this here and form it to the uh to the to the paper it'll catch fire um i need some of that flame proof paper that the glass blowers use but i don't have time to order it i want to do this now it takes a week to get it if i can order the clean proof paper this is the bottom part so it's going to be over here in the bottom corner and where i've got it marked here with a marks a lot i'm going to go ahead and make that curve going on top okay so we'll heat this up and we'll let it droop and make that curve oh i didn't do that's all that i wanted okay okay now i'm gonna come around right here that's good okay from there okay okay right at that point there we start doing the curve what i'm going to do i'm going to fasten it down and then we'll take it and we'll heat it until it's on the table and we'll just bend it around until it matches the uh the wire okay go ahead so so okay late in the circle so what i have to do i have to take it right here and come around okay collapse a little bit more okay that looks really good okay next one we're going to do is another easy one number five okay next ones we're going to do we're going to do the nines and the sixes all right for those the electrode for the top will be there it will go around completely and the bottom will be where we have the fill too okay all right okay so so so so um wow that's damn close okay i just have to bring that together a little bit okay so okay all right didn't go together okay i gotta come down flat so i've got that this is tough so i gotta flatten that pan okay i'm just going to heat it here and press it in place that looks good okay it's very flat sorta okay okay we're that has to come around just a little bit more okay that's close very very very very very very good so so there pretty close okay so if i can if i can get it down it's going to be pretty close to perfect okay looks good okay made it all in one piece yeah all right we've had it pumping for a half an hour and oh let's see 2.5 times 10 to the minus 54. and when we put neon in it it's nice and beautiful we just have to we have to we have to pump it at low vacuum if we don't go down low we have that purple glow that takes over okay we're done let's go ahead and seal it off start your clothes out all right getting a little bit of blue and purple up here so we're gonna just let it bake a little bit drive the last of the gas out all right five torr two three four reddit five torque all right beautiful orange ah look at that that's gorgeous okay all right we're just gonna let it go ahead and bake out the electrodes right okay we've got this one processed and it looks pretty darn good okay that's two tour let me see i'm gonna run it up to three four four point ninety three that's good enough that's beautiful beautiful it's gorgeous alrighty okay i just vacuumed it and all right got good solid color with no blue no purple all right let's go ahead and seal it up oh it looks okay all right all right now we're going to put the neon in this is for good three there's four all right five torque it's beautiful alrighty alrighty whoo gorgeous okay okay we got the nine all processed or the six whichever so what i'm gonna do is i'm going to shut this off and we will seal it off so that looks good that looks good it's it's kind of orange flat see how the four is a darker orange than the three the three's got too little pressure in it the pressure's too low all right i want it to be good job i'm not gonna i'm not gonna just leave one of them bad all the rest of them are dark all right now what we're going to do we have to make the support for the numbers okay now let me get a number so we get a size okay here we have the size of the number that will be up in there like that okay so we need an inside that's going to be okay can we go four inches okay four inches and put it right there so from the very bottom we're gonna go up okay three and a half inches eight eight and five eighths um all right that is our base okay next we need the step up which will be eight and what do i say eight and five eights okay i need a piece of board eight and five-eighths okay clean it up so absolutely perfect okay we've got the um router mounted in the table saw we got a fixture underneath there to hold the router so we can use the table saw as a router table all right [Music] okay that gets our edge done okay we'll sand it a little bit okay the next thing we have to do we have to go from the base up three inches to the platform okay that's gonna be where we mount the uh mount the numbers and then underneath is where we're gonna put power supplies [Music] [Music] okay all right that's the base now this will fit right down over it perfectly like that and it'll go down on there oh that's so perfect that is so perfect got to put it first to make sure because we cannot stick out past the edge of the glass and we'll be in real trouble okay he's seven inches so we'll make it seven and a half inches okay two okay what i need is a quarter inch groove right there and we're going to put the quarter inch piece of material right there so i'll put it in the milling machine and we'll mill a slot in the wood oh god what a work i went on the wrong side okay there's our slot so we got a little extra one in the wrong place what the hell was i thinking of oh my gosh this has to fit in the slot i've got to get this to where it fits into the slot okay it's a little over a quarter inch so i'm going to belt sand it [Music] now the next thing this is got lacquer on it we got to get rid of it oh yeah that's just taking the lacquer off of there so [Applause] now this is a little bit floppy so what i'm going to do is i'm going to put a rib here to hold it vertical right there see that's going to keep it keep it stiff from wobbling this has to be black let me get some paint okay now five is going right there it's good okay [Music] what we're doing is we're making little pieces like this and we stick stick that down on and then the glass tubing goes in there we use heat glue to hold them okay it's number two the wire broke off so i've got to fix that for just uh see how that broke off what i'm going to do is i'm just going to grind it a little bit and then i'm going to wrap a little piece of fine wire around there and then bring it around to the outside okay see how we've we just wrapped that wire around that tip got it on the terminal and then brought it back and wrapped it around the base here to hold it that'll make it to where we can do it otherwise i got to cut the end off and put a new electrode in it that would be a lot of a lot of work okay we're ready now that we've got the two in there we can put the seven total disaster broke it's way down in there oh i gotta take them all off how am i gonna do that let me remove that support and then we can put the floor and go oh look at that oh that's just that's just uh that's slicker it's not on a doorknob okay we're just gonna put the four there instead of the five we'll put the four at that point it doesn't matter that goes on there two more supports to take care of the four and that that replaces the five with the four okay i remade the five i took the five and fixed it i was able to just seal together the broken part and put a new a new electrode on the other end and that fixed the five so now we've got all of the numbers mounted i've got one that sticks out okay no problem at all okay so the next thing to do um is to wire it i'm going to put the terminals what i'm going to have is i've got to have 11 terminals i need a common and um 10 number terminals okay so i'm going to go here i'm still in a little bit of a state of shock i just got back from the hardware store this screw you see this screw here it's a number four screw one inch long brass screw just plain old brass wood screw 33 cents each at the hardware store i can you imagine that i mean inflation is beyond anything imaginable i looked up in my um mcmaster's car catalog what they were back in in 2000 and they were three cents each they were three cents each they're now 33 cents each that's a factor of 11. in 10 years they've gone up times 11. not 11 percent not 10 percent if they've in 10 years they've gone up times 10 in price times 11 in price you know we're we're in for a heck of a rough ride here where's my kitty where's my kitty you want to say hi to the people huh you want to say hi to people oh you're running away huh you don't want to be in the picture hmm hey my little baby okay the next thing we're going to do is wire all those damn things in okay i'm going to take it in the house i'm going to connect all the ones at the top half up and that will be the common then the bottom ones will have relatively short wires to each of the number terminals by using this very fine wire it makes it to where we're very we're much less likely to break the terminals off if i break them off then i've got to i've got real trouble yeah i just wrap you'll just wrap it around there like so and trim it okay and then another one here okay and come up and we'll hit this one okay that connects two of them together see it's fairly straightforward to do got all these little strings okay now i've got one here and one here okay just i'm just wrapping this around there there's no current and since it's so fine a wire we won't be seeing it okay now very carefully okay number six we broke off if i can't rescue it um it's going to be an almost impossible thing all right let me get the diamond uh grinder i have to grind a little bit of the glass off to get to it i just have to get to it enough to get a twist of wear around it [Music] the wire's sticking out just a little bit i'm just cracking the glass off the base okay now i go over and i'm going to go around it i'm going to go around here a couple times then i'm going to go around here this is that bonded stuff ultraviolet glue and i'm going to stick a dab of it on the end here to hold the wire okay and then we hit it with ultraviolet it hardens up just like that i mean it's just that's the neatest stuff you get these for they're like ten dollars each they have you know maybe 50 75 glues in them okay see that'll hold that right on there okay we rescued it i probably ought to take each one of those and put that stuff on there i'm going to test it before i do that i'll do that but i'm going to test it first breaks off in there it's game over we've got to be damn careful if we break it it's game over it will be game over okay this will be [Music] try again go way down there you go okay okay here we have a piece of paper cut out the exact size that fits in the base okay it's going to be a tight fit all right we'll line our transformers up and then our trim pots and not trim pots i'm sorry relays they look like trim pots and then we'll have 120 volt transformer little power supply for the high voltage then over here we'll put the um the the oscillator in okay we just heat glued that transformer onto there okay that is uh fits perfectly okay we got plenty of room over here for the high voltage switching section okay we've got to have there is no ground feel used to that okay here we have the third iteration of the power supply okay the first iteration was going to be the individual power supplies for each digit well it turned out those little cores i could not wind the high voltage on without the marking over so that went down the drain okay the second one was an inverter using a high voltage transformer that was operating at 24 kilohertz 20 24 25 somewhere around there well it turns out that the capacitive coupling between the digits caused background glow the digit that had the voltage on it would go ahead and couple through to the other digits just just through the capacitance in the air at that frequency and it would cause it to have a kind of a ghostly glow so you you always had several numbers lit and that was no good at all okay so now i lowered the frequency of the inverter to 400 hertz i had i had another transformer here that operates at 400 hertz and puts out um the required voltage okay that works good so we're going to go ahead and mount that transformer in here and that's what we're going to use and it fits right in there i mean i won't have to remake the board okay so i'm going to get the heat glue gun going okay i'm just going to put just a little bit of glue okay and just stick that right there okay and that's gonna hold this the transformer there the primary um is the hundred volts at 400 hertz the secondary is the um 2500 volts it puts out at 2500 volts at 400 hertz okay five is hooked up already okay we've got six and seven okay that's six and the next one's seven okay so six we can go here okay that gets all of our wires hooked up okay this is the first test first test coming up oh all right first test of the enormous huge nixie okay i need control voltage and power on oh we got a five all right there's a nine an eight a zero a four one a seven a two a three and a six haha look at that whew man man that's a big one huh okay that's it wow okay next we have to do the envelope got to get the envelope on it but at least the electronics is all working seeing these wires here we'll go to the control board of whatever we're going to use to make this i'm going to make it into a single digit clock and these wires here will go to that and it'll go ahead and switch it see these wires here use a separate 12 volt power supply from the main high voltage that way we don't have 120 volt ac uh connected to these wires we we don't have to use an isolation transformer to um to keep keep the line voltage off of the um arduino or whatever the heck it is all right let's take a look at what we're using for the power circuit we're using an ir 2153 fet driver this is a self-oscillating fvt driver it it gives you your two gate signals for for a uh uh i don't know what you call it a uh totem pole fet pair and it oscillates by itself like a 555 you have a resistor and a capacitor that sets the frequency this particular device is useful up to 100 kilohertz you can go higher than 100 kilohertz with it it'll run at 200 kilohertz but it will have trouble driving fet gates at that frequency you can drive smaller fvts but if you want to drive some you know usefully sized ones uh this thing's gonna have slow uh pretty slow uh rise times on it you know it just it just doesn't at that kind of frequency you're not gonna have a very sharp waveform so stick to 100 kilohertz and lower if you're going to use this device and expect to have good efficiency you know where your fats don't get scorching hot okay we come in with 120 volts into a small transformer this is just a very small transformer because all it does is supplies the power for the ic and the gate drive so we need 100 milliamps and that's all so we have 12 volts coming out at 100 milliamps to supply the ic okay we have a thousand microfarad 16 volts to get the ripple off of it and then we have our 20k trim pot and a 0.47 timing components this allows us to go from about 250 hertz up to around 2500 hertz with the variation of this 20k trim pot okay we're running at 400 hertz and now there's another capacitor on here that's a supply capacitor that's this one we have 10 microfarad here now this capacitor has to be sized such that at whatever frequency you're operating it will hold enough charge to charge these gates and you don't have too much trouble when you're above about 20 kilohertz or even 10 kilohertz you can use like a 0.1 microfarad in there but when you start getting lower than 10 micro lower than um you know a few kilohertz then you start having that voltage drain off of that capacitor before the uh before the gate switch and that can give you some trouble that can give you some trouble so it's better to make this capacitor a little bit larger in size than what you'd normally think a 10 microfarad will handle down to 100 hertz operating frequency and i can't imagine wanting to run this thing lower than 100 hertz you may want to do it at 60 hertz if you're making a 60 hertz inverter but even that has better solutions than this okay we want to limit the surge current into the gates of the uh fvts these are effectively about a 2000 picofarad capacitor to ground so if you just have that hook straight onto there and you switch it from zero to 12 volts just like that there's a lot of current that flows through there and that can overheat your driver that can overheat your driver bad so what you do is you put these 68 ohm resistors the value is not critical can be anything from 20 ohms to oh no more than 100 ohms if you have higher frequencies if you're above 20 kilohertz you go down in value on these you put them down at maybe 22 ohms but at 400 hertz 68 ohms slows the edges down just right and you have no heating of the 2153 at all okay we when you turn them for power first on you want to make sure both of these fets are off you don't want them to ever uh be both on at once otherwise your power coming in is shorted straight to ground and what that'll do is it'll burn out your 150 ohm 5 watt resistor here that 150 ohm 5 watt resistor is used to protect the circuit um you you will choose this resistor depending on what load that you're driving if you're making something that's high power you know maybe you're having something that's pulling 10 amps out of it you're gonna make this resistor it may be only one ohm you may only have a one ohm resistor in there if you're pulling 10 amps out of there that would give you a 10 volt drop across it the 10 watt resistor but we're we're running um only 100 milliamps out of here so 150 ohms does very nicely to limit the current and that makes it to where when you first turn the power on this device here supposedly is maintaining both outputs at zero until the power comes up that does not always hold true if you have a separate supply onto the fats from the 2153 so if this power can come up before the ic gets its power and turns on then you can have these two gates floating and they may be on at the same time and you'll have you a momentary short there that can um severely heat this up you're going to put an amp through that resistor and that's that's a hell of a lot more than five watts and it's gonna chance i've already blown one of them out i've already blown one of them out i had a short circuit on the output and blew it up but okay normally you won't have that happen okay now when you couple the output of this onto a coil you cannot just straight couple it this is a a unipolar drive in other words it goes from the the output goes from zero volts up to whatever your supply voltage is it's not bipolar okay to drive a transformer you must have bipolar drive you cannot drive it unipolar like this what you'll do is you'll saturate the transformer in one direction and you'll only get half the output from it that you would get if you drive it in both directions so what you want to do is capacitively couple it and that takes it and it moves that waveform to where it's centered around zero and it'll go to minus 50 volts and plus 50 volts instead of zero to 100 volts and that way the transformer is driven in both directions and that doesn't saturate the core keeps the core from saturating so that capacitor always has to be in there if you're driving a transformer coil from this type of a circuit a unipolar circuit now if you're using a full bridge that drives in both directions you can connect directly it's still risky to do but you can do it all right next we get to the output okay this transformer uh takes the 100 volts peak to peak here and converts it to 2500 rms that's 5000 volts speak to peak and about 2500 volts rms and that's what we use to drive the uh the numbers in the nixie tube and that'll that'll drive the nixie tube in one direction and then the opposite polarity in the other direction so we have both electrodes in the nixie tube um uh getting equal amount of wear okay and the uh the current that into this transformer is limited by the combination of this 150 ohms right here and the 22 microfarad you set the 22 microfarad so you get a good square wave here without any droop and then you take this 150 ohms and you adjust that to where your your b plus voltage gives you whatever you need on the output and that way you can you can keep from overdriving the numbers you know if we just hook this straight onto line voltage i mean we could get oh 50 milliamps out of here and really cook those tubes we don't need to do that they're plenty bright at 10 milliamps so what i did was just pick the value of the um the limiting resistor here to where we get 10 milliamps on the output and that gives us enough current in the nixies numbers to make them break brilliant okay now how do you switch 2500 volts oh my goodness and that's a peak voltage of over 3000 volts the the it's 2500 rms and how do you switch that 3000 volts peak voltage well we had to use homemade relays okay and you can see on the other uh part of the video there you can see we made those those um relays up by hand made ten of them we have one for each um one for each digit and by doing this we gain two uh advantages the first is we're able to switch the 3000 volts the relay contacts open about a quarter of an inch so that lets us switch reliably the 3000 volts now the other advantage we get is the circuit for the coils that drive the relay is isolated completely from this circuit here so while here we have the comet in this one is hooked straight to the line so if we hook it in hook the line up to where this is ac hot the all the circuitry in here is at ac hot and if you touch it and you're grounded you can get a shock well we don't want that i mean our control circuit we don't want to have whatever's controlling our mixing to be hot at certain times we want it to be completely isolated so that it's always safe so we have these relay coils are isolated from the main circuit so we don't have any connection to it and we supply a separate 12 volts from the circuit that's driving the nixies to run these coils and then our controls uh to a connector here that has those relay coils connected to it now the way that it's being done you see that get another piece of paper here [Music] okay we have the high voltage and we come out one of them goes to ground and we have all the numbers okay we take the common for each number and we connect all of them together and then we take each lower terminal the other terminal and we take it and we run it to the relay okay so what this does is see and then we have our coils here for each relay now what this does is not only do we have the voltage drop of the tube but we also have the gap of the relay to break that 3000 volts so we on the relay itself we don't ever have the full 3000 volts now another thing that i've done to make this even more reliable i've taken the high voltage supply and i have another relay and a power in goes through that relay and we take each of these relays and we pour them together and those go on to the other i put those backwards dumbed up so all of our relays go to plus 12 volts plus this one here that turns power to the high voltage so when we ground one of these an open collector circuit in other words then that turns on the high voltage relay and it turns on the high voltage and then when we unground the high voltage relay not only does that terminal open but the high voltage power supply shuts off and that makes sure we don't get an arch on the relay and that that makes it to where we can reliably switch without um having the any hangover from one of the uh one of the one of the digits okay and that's the basically how the thing works and it's the whole thing is just wired up so we have all of the commons of the relays going to 12 volts and then the control all we do is make that control to ground and it takes that and goes to the input relay and shuts off the uh or turns on or off the uh input 120 volts and that's that's the basic how the whole thing is working and this part of the circuit entirely is fitting inside the the base of the nixie you know the the relay bank and all of the electronics is down inside here so we don't have to run any high voltage or anything else out of the um out of the nixie so what we have coming out of the nixie we're going to have our control wires which are completely isolated from 120 volts and we're going to have our plus 12 volts in com which go to the same board that's isolated completely from the 120 volts then here we have standard 120 volts to the line you can plug it in either way because you don't care whether the circuit itself is hot or grounded okay everything that's in there is closed in by the glass case so that you're not going to get shocked okay that's how the electronics works okay well there it is the humongous mixie i mean to say look at the size of that sucker i mean it is definitely big oh my goodness gravy we got our wires coming out the back i got it hooked to a power supply now let me turn it on and we'll see what it looks like okay now turn this on 12 volts there we go there is our pc2 that's just totally amazing switch isn't hooked in order of course okay success on a project now what i'm going to do i'm going to make this into a single digit nixie clock i'll go ahead and make that in another video this video is already too long all right that's it you

Channel: glasslinger

Views: 79,208

Keywords: glass blowing, nixie tube, nixie

Id: T6SUaZ8PLeI

Length: 118min 25sec (7105 seconds)

Published: Thu Aug 19 2021