The "M" tube neon-mercury DC migration effect (with schematic)
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- Опубликовано: 5 сен 2024
- Story time. A very long time ago I was gazing in the shop windows of a large Glasgow department store called Lewis's. They had some unusual illuminated tubes in the window that had a plug-in power supply and a coiled cable leading to a very narrow plastic tube with a neon tube inside it.
I asked a shop assistant if she knew where they got them from and she contacted the window dressing team who took me up to their workshop.
They said they had been a bit unreliable and gave me a faulty one, warning me to be careful as one of their crew had received an electric shock from the wires while it was unplugged.
Inside the plug was a circuit board potted in deep resin to hide the components. It had two spade terminals at either side - mains in and high voltage out. The label indicated which terminals were which and also gave a footage range for the neon (actually argon/mercury) tube.
These units may have been made by Masonlite - a big player in neon sign components.
I reverse engineered the circuit, carefully digging away at the resin to reveal the hidden components. Once I'd worked out the circuitry I started experimenting with DIY versions, and got some custom tubes made by a Glasgow based company called The Neon Workshop.
It was always a pleasure visiting the Neon Workshop, as Donald the manager was a veteran of Glasgow's sign industry when it had competed with Las Vegas for big animated skyline signs made by a company called Franko Signs. It was interesting hearing about the older technology used in them.
Running tubes on a DC multiplier does have some disadvantages. It restricts the length that can be run, only seems to work properly with mercury based tubes and has a side effect of causing mercury migration where the mercury vapour in the tube gradually moves to the negative end and either needs the polarity reversed, or the bead of mercury shaken back to the other end.
The upside is that it is a very simple and cheap circuit that can be made with ordinary components. I've seen these used in some of the neon radios that were popular for a while. The clear case had the multiplier circuitry in full view.
The use of multipliers also allows very simple circuitry to be used to animate short sections of tubes. I made a prototype module with four multipliers and opto-triacs that could connect to my fairground lighting control system.
Note that the circuit I show in the video is a very basic 240V circuit suited to about 2' (600mm) of 12mm diameter tube. Using a longer tube may result in striking/flickering issues and a shorter one will put extra strain on the current limiting resistors.
For 120V use or longer tubes it will be necessary to increase the number of multiplier stages with beefier capacitors for the first few stages and then a decent number of the 10nF capacitors to get the strike voltage.
Treat the output as high voltage referenced to the mains supply. To quote a dutch friend (Dirk Boonstra) touching the output of these power supplies will blow all the hair out of your head.
I used to use double insulated meter lead wire to connect to tubes with crocodile/alligator clips (while the power was on!), so it's a miracle I didn't get zapped.
This circuit is presented for personal experimental use only. It's not really suited to commercial use, especially with the common availability of electronic neon power supplies.
The DC mercury migration effect is what I was aiming for in the "M" tube. It has a deliberate dip in the middle to hold a droplet of mercury in an attempt to do a colour split when the mercury migrates through the neon carrier gas. Where just the neon is present the tube glows orange, but when the mercury vapour is present it glows blue. It works, but takes a VERY long time for the migration to occur.
Although using the same science as a germicidal UVC tube, no significant amount of UV escapes from this tube due to the natural blocking characteristic of soda/lead glass.
Compared to modern high frequency electronic power supplies, the simple DC multiplier produces much less electrical and RF noise. Possibly part of the reason they were used in the ornamental neon radios.
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The Cockcroft-Walton multiplier is a splendidly clever circuit, pumping electrons up like water out of a mine. Cockcroft and Walton won the Nobel prize for the research they did with it, and they deserved it.
In addition to current limiting, series resistors in the output are usually necessary as most gas discharges have a negative resistance characteristic, so without external resistance they can oscillate or become unstable.
👍
I understand what those words mean individually but not together in that order… not your fault I am just a idiot. Must go I just spotted something shiny
I was thinking the same thing. Might explain some of the instabilities Clive mentioned.
@@oscobblepotcobblepot6972 once you reach the appropriate voltage across a tube filled with the appropriate gas or an LED, it will conduct current through it, but, in its conductive state, it has a very low resistance. You need a device which will limit the current through the gas or LED.
@@mgancarzjr Yes, the voltage across the tube is nearly constant, irrespective of current flow, and can even vary due to arc temperature or the influence of external magnetic fields. Thus you really want to drive it with a near constant current, as otherwise you can make something with negative slope resistance, which can have quite a bit of gain, and amplify noise well. You used to get tubes deliberately deigned for negative resistance, used as amplifiers, and diodes as well, which have a negative resistance region in the curve. The diodes are still around, used in microwave detector circuits as the oscillator, as the circuit is very easy to assemble ( one component in a cavity) and very reliable.
There's always something so appealing about real neon tubes. It's like a combination of chemistry, electronics, and art.
First time i've ever seen mercury migration in a clear tube. Very interesting.
Overall old electronics look more interesting. Now everything is just squares of epoxy.
Applied science did a great video on a mercury migration based time meter a while back which shows this phenomenon in a different application if you're interested: ruclips.net/video/Cxj399LuX1M/видео.html
fully off topic here, but your picture made me realise the ANTISTAT UK logo and the biohazard symbol share a lot in common.
sure is, a real aliveness about neon. That's why I became a neon artist (and they look damn good even in a smartphone photo taken by someone half drunk, whereas most cool looking lighting doesn't photograph well without a really professional setup)
Used to work in a shop with a large set of neon signage outside. Majority of the sign used mercury filled signs, in the favourite colour of Clive, pink, and the 3 signs all had running patterns and flashers. I kept a few spare tubes of the most common type, a bar and an arrow, as they were going to fail on the odd occasion, though most were from breaking.
Solved the breakage problem by letting it get out in the neighborhood that the glass, while the perfect size for smoking your crack, was also going to shrivel your nuts, and the weekly breakage stopped. Helpful, as each one cost around 50 pounds to make, and I only kept 6 spare ones. Only got 4 left, as the shop closed, and the signs were removed. Did however get another 2 new pieces for another sign, from a shop that never opened, along with 2 new neon transformers. One white, one clear mercury filled glass. Also have an electronic ballast I picked up, along with around 4 regular old lethal size neon transformers, of various sizes.
All the neon now sits wired onto a plywood board, and gets lit up on occasion, though I should add in some flourescent lamps, the high voltage EEX type, as well.
up until '67, I worked on neon signs working with 10KV+ transformers [from memory] fault-finding was fun shorting out letters with a length of cable in your hands live :)
The shorting sections with wire was common. Quite exciting.
I remember doing this on signs standing several stores up on scaffolding. getting shocked was not fun. if I remember right, they were 12kv center tapped transformer
@@jasonharrison25 Was that a painful shock?I think those were 30 mA transformers.
It reminds me a bit of a service timer capsule in a gyro. It is a very thin glass tube about 40mm long filled with two different fluids that don't mix, about 95% one fluid and 5% of the other. There were two electrodes in each end. A small current was passed through from end to end, and over the course of weeks the fluids would slowly exchange places and the small blob would migrate along the tube. When it reaches both end electrodes, the different conductivity was detected and popped out a service flag in the display warning you it needed an overhaul. When it was serviced we swapped applied dc current around and the blob went back the other way. Sometimes one would come in with a fault close to service time, and we would hurry the timer blob along with a bench supply over the course of about a day.
And for some reason, I am imagining a small flag popping out and unfurling ala Looney tunes...
@@adragontattoo More in the line of a small magnetic indicator that would flip state from a black background to one with a yellow one. As they both are latching, and have a small switch built in, the flag flipping to yellow would change over the small contact set inside, and this was used to operate a yellow annunciator on the master caution warning panel, giving the pilot a flag that a system was in a degraded state. There was another set of indicators that would be right next to this one in the unit, which was operated by the self test circuitry, and that one flagging would illuminate a red annunciator light on the panel ,accompanied by a tone in the headphones, that the pilot would need to stop, using the master caution reset button, which would tell him this system is not reliable and is failed.
Generally, when you power on the aircraft, every system will light up this panel for a few seconds. Both to test the caution and warning system is working (the panel lights all come on, then go off over a few seconds as systems complete self test) and to show the avionics are all coming on properly as well. 10 seconds or so after power application the board should be all off, and you just reset the master caution button to clear the tone medley. Any that are still on, that you do not expect (oil pressure and hydraulic systems, as the engine/s are not running, and low speed warnings) are then repaired before you take off.
@@adragontattoo actually a little painted paddle on a pivot, much like a tiny little railway crossing barrier.
dude that is genius. in a very different application I'm reminded of mercury memory in computers. An incredible and cool solution
I used to work as a neon bender for eleven years but I wasn't very involved in the electronics, so this was an interesting video. As far as I know one single neon bender now supplies all Nordic countries since LED technology covers almost all scenarios. There is something special with pure neon light in a clear glass tube which can never be replaced with LED though.
It's become an art and architectural medium now.
I dread the day they will throw out the tubes in the roof at Hötorget subway station and replace them with energy efficient but soulless LED strips. And I agree that nothing can replace gas discharge in clear tubes. I even bought a small neon tube with my own signature to wear on my overall at KTH...
Such a nicely drawn schematic! Beautiful symmetry.
It's a very symmetrical circuit. The PCB looks good too.
I know it's kind of silly but I tend to give way to size or convenience for symmetry in my projects and I always feel just a little bit more proud of a project when I can keep it symmetrical.
The story is more interesting than the video to me. Those were the days...
More like this please!!!!
We love LED but some of us love gas discharge lighting even better!
Plasma is literally the most beautiful thing in the universe. LEDs are boring.
That's a interesting looking lamp.. Very retro .. no SMT components or microprocessors... just spicy voltages..
Ah, thanks Clive. This reminds me of the "Quad" as in quadrupler in my CRT projector. It's one of the last before the digital age and was "state of the art" at the time..... (turn of the century). Pushing out 35kV or so, the quad is probably the single biggest point of failure for these devices. Replacements are getting hard to find. The components are potted in a rubber like substance, and amateur attempts at making replacements don't last long at all. This has just made me smile at the number of hours of my life spent trying to converge these machines, and then sitting there wondering/waiting/expecting the quad to go "pop"!
I suddenly feel very old! Turn of the century has always implied to me ca.1900 but you're referring to 2000 and that makes me feel ancient!!
The problem with making them is getting all the bubbles out, you need a vacuum pot to degas the resin, and then the inside will not have any voids. Reproduction ones often do not get the gas all out, leaving them with built in failure spots. The diodes and capacitors are easy enough to get, it is just the assembly is harder. In a projection set there is enough room you can even DIY it, using microwave oven diodes and high voltage capacitors, making it much larger, to get the insulation needed, and use common potting materials as well.
@@SeanBZA Yep, many have tried..... Even the vacuums to de-airate are common enough..... yet still we never got the longevity... If anybody has the "magic", there is a small but eager market out there!
I fitted a load of these back then ... in pubs and hotels. Mostly Seleco. Many happy hours spent using 68 parameters to converge the guns. Was tuning one in on christmas eve in the Park Hotel in London connected to the in-house feed that was unrestricted. Slightly embarrassed when the auto-tune found and displayed 8 foot wide images of their hardcore porn channels to a bar packed with well-dressed yuppies. Gave us a laugh though.
I really love the look of the simple enclosure and circuit style. I have always liked looking at neon lamps which might explain why I purchase neon LED strips. Finding Neon Tubes is faar too difficult and I'm worried that I'll shock the hell out of me with it. Great Video as always.
While I work in a sign shop and have seen mercury migration with some of the cheap DC electronic transformers, never really thought of combining the neon gas with the argon/mercury mixture. Neat effect.
It would be cool to modify the power supply where it could supply AC and DC option as well as being able to reverse the polarity. Maybe even control the switch with a microcontroller to switch with the typical mercury migration. That way it can move back and forth or even distribute with ac applied.
That's a very interesting story, and I bet you never thought you'd be able to make such good use of the tube (i.e. share it with so many people!) when you first obtained it! Makes me want to hoard more interesting stuff but the shed is already full!! :-))
"You guys want to see the circuitry"
No I'm just here for the fancy light. It shines. 😉😆😆
Mercury migration is used in hour-meters.
Tiny glass capillary tube with mercury fill at both ends and a tiny gap between.
There is electrolyte in the gap, current flow through the tube 'plates' mercury onto one end at the expense of the other.
The gap 'moves' to indicate operating time.
I saw those fuse-like devices on Tomorrow's world when they first appeared.
the mercury coulometer / electrochemical hour meter was only very recently retired from one of its final uses on deuterium UVC lamps in favor of the less toxic LCD digital counter.
I've something similar in my junkbox which came out of an early VHS video recorder.
@@Muonium1 that will only motivate people to smash the counters to pieces and spread them around even more. if you make a helmet twice as strong youll find people hitting their heads 3 times as hard.
@@echelonrank3927 um k sure, whatever you say
First a concern about the UV from the un-phosphor covered lamp, but I see you address this in "Story time"
Similarly therein you cover the HV output dangers from such a circuit. Dirk Boonstra (presumably not the one on wikipedia who was a member of the Dutch resistance) provides appropriately deterrent symptoms for someone as hirsute as you.
Finally, whilst you are still in Glasgow maybe a video about old Neon tube companies would be worth a thought. A quick search revealed litle apart from a Science Museum link to Franco (note spelling) of Oxford Street and Neon Workshop of Wakefield. Maybe Donald has some stories.
Sadly, I doubt Donald is about any more. He was old then and a chain smoker.
Ordinary glass blocks UVB and UVC quite well, but it doesn't block most UVA. UVA doesn't cause burns like the shorter wavelength UV does, but it can still damage skin and eyes, given enough intensity and long enough exposure. Mercury has a prominent spectral peak at 365 nm, which is well within the UVA range transmitted by glass, and potentially harmful. (Sunlight, too, contains significant UVA.) If staring into phosphor-free mercury tubes is your thing, a thin film of polycarbonate makes an excellent UVA filter, while passing visible light with only slight attenuation. Safety glasses are often made of polycarbonate.
Used a circuit like this and the classic ZVS fed LOPT. A friend managed to bypass the diodes in the LOPT so we got some good HV AC with a decent frequency out of it.
It made something north of 50kV DC and was tons of fun.
It made a loose fitting t-shirt cling to your skin like a spandex leotard and the insulating oil flowed upwards along wires.
Oh, and a drunk friend pointed at it and got zapped, up until that moment we had operated under the assumption that a chock would probably land you in the ER.
So another pleasant surprise!
I heard a RUclipsr got lost in there. They found his camera nearby but no body was ever found
I often struggle to understand but keep watching your videos Clive in the hope that one day I may ‘see the light’!
It'll all make sense with time.
You're using it upside-down. It's actually a "W" tube, also known as a Double RUclips. 😂
This is fascinating! thank you for the commentary and the description of the diagram! Thank you for this contribution to humanity!
Hi Clive. Your hands are looking well cared for. Are you using a lotion to avoid winter dryness? Happy New Year from your friends James and Derek from California, USA.
It's mainly due to lack of real work during these troubled times.
Clive made hard work of describing the startup, high voltage causes the gas to break down thus initiating an electron flow👍
Very interesting, the story in the description. I didn't know about the migration effect - you dazzled me again :-)
I love the wireless mic.
BigClive, I would love to watch a time lapse of the tube warming up. Your store in the comments would be an amazing voice over story. I have never seen a tube like that. Thank you for sharing it. My mind is now wanting to make one. This tube is almost like the OG of Color Change LED.
This is really cool! I’m so glad to see new neon videos from you! I have an old neon/mercury clock that can instantly change the color of the tube from red to blue by varying the duty cycle and frequency of the drive voltage. It’s just based on a pair of 555 timers, I’d love to see you reverse engineer that!
I must admit an initial shock at seeing Live going to the negative of an electrolytic capacitor. Very interesting video. I really enjoy these odd gems you come up with, Clive.
Thanks from Texas Clive.
wow, that's very interesting. I thought many circuit board potted inside from black box. And this very Beautiful "M" tube neon.
Morning Clive from a grey south east London...great video that was very nostalgic for me. Back in the 70s Lewisham and New Cross a couple of years before the area got a massive kick up the harris with the anti NF riots the only bit of colour in the landscape was Pearce Signs by the bus stop opposite New Ctoss Gate Station...the neon man climbing a red neon ladder with the multi coloured Pearce Signs logo always looked so exotic !!! I remember how easily one,even as a 14 year old had access to the factory floor...I was fascinated by the whole shebang and had the "audacity" to suggest to the manager that they should make custom signs for peoples homes...I drew up an example that consisted of my name ALEX and an apprentice made the tube up...sadly I never got the "driver" to run it but lives on with my collection of 'industrial glass art' ie 50,000 watt tungsten bulb,this beautiful microwave valve(with delicate wave guides and thick bands of copper around the glass envelope) about 2 foot long with a magnetatron on the bottom. I have always loved glassware but this mode. The fascinating and seemingly impossibly delicate element and structure that supports it in the 50k bulb is 'art in the eye of the beholder' ....this one anyway. 👉🇬🇧👈👉❤👈💯%
You can buy cheap electronic neon transformers on eBay.
Clive, I'm not sure if I mentioned this before in a comment, probably you know about the mercury rectifier at the Laxey railway station. It's retired now and to my last information it's on a powered display (maybe not always). Photon made a glorious video of the one he has, but I thought it'd be interesting to see a similar one from you, whenever covid and other circumstances allow that. Keep 'em coming, great channel! 👍
Good old voltage multiple , is a circuit I use a lot , especially when I need to squeeze a lot of electronics into a small space , and the circuit uses a low currant. It allows me to use a smaller transformer for example a 6 volt transformer to provide an 18 volt supply , it is an under used circuit
First Thoughts…
Cockcroft Walton Generator.
Immediately recognised circuit diagram.
Second thought…
Must thank Big Clive for somehow teaching me about electronics.
🙏 Thanks
No I came here to see the story lol always fun videos I'll have to look in the description.
I Ran into a guy who fixes neon tubes a month ago. My local theater which is quite old and I am under the understanding he's somewhat local and they wanted to get their tubes fixed.
This theater used to be a garage to repair cars before it was converted and sometime in the history it was the first phone exchange for the town thank Little House on the Prairie the wife of the general store owner in the corner listening to everybody's phone calls and patching them.
I do like your stories in video form over text form.
The whole time I was staring at the schematic, all I could see was a delicious, round, bowl of porridge! Maybe I shouldn't watch you Clive while I'm hungry 😆
Wow I read the story you put below, fantastic article.
Not all phosphor coated lamps contain mercury. Neon also has some UV emission lines, which can excite a phosphor to give other colours such as pink, a more yellowish orange and a deeper red.
I'm fulfilling a life-long goal of learning electronics. I feel like when I can finally follow a Clive circuit video all the way through and understand it my Jedi training will be complete.
That was a nice story in the description. Could have well been in the video. ;)
You should have a Bread Board and put experiments on for us to see the outcome of changes that can be done..
Awesome neon tube big Clive
Thank you for sharing this interesting circuit.
I have a small collection of gas discharge tubes and their related electronics. Also some violet wand stuff in two colors. I love the glow.
your the most detailed electrical channel
I hope you had good holidays big guy, cheers!
i've got one for you, big clive. 20 years ago when i was an electrician's trades assistant, the boss, who is a know-all smartarse like me (we both readily agree to this title ) asked me if i'd ever heard of induction lighting (i think that is what it was called). he'd been asked to replace the tubes in a commercial establishment. after some hunting around he found some. to the best of my memory, they were circular fluorescent tubes with no electrical connections. the current was induced into the tubes. he was told that the tubes are extremely long lasting, the ones being replaced were about 50 years old.
there are some youtube videos about them too! i'd forgotten all about the existence of the things.
I think I have one of those. It's two feet long and has a metal stud at each end instead of pins. I have no fittings to use it with, alas.
@@peterking2794 , i typed "induction lighting wikipedia" to find a page on the wide range of things that operate by induction. they can be highly efficient. go and see if what you have is there.
I have an induction lamp here. It uses external coils to induce current flow in the sealed tube.
That glow is very pretty.
Its an important thing to note the mercury usually used in neon tubes is supposed to be a tiny droplet, these weird tubes are an oddity that uses relatively a lot of mercury
The guy who made this tube for me was notable for adding quite a lot of mercury, and also not using a diffusion pump. (Hence the staining.)
You could add a photo sensor of some sort to detect the color,
to trigger a relay when red gets to a point.
Essentially a clock, but with extra steps, and a dubious accuracy.
_(I do not know how consistent the mercury precipitation would be)_
Thanks for this and the tale told in the description - wonderful stuff!
Thank you for pointing out the friend you quoted was Dutch. I don't think I would've been able to trust him if he wasn't.
There was no “One moment please”. I look forward to those as I naively expect you to return with a tray of ice cream and snacks, like in the intermission in cinemas of old. Ah well, we live in hope 😁
Nice. The good old days when safety advice was 'be careful.' LOL.
NeonTube sounds catchier than RUclips. Hope you are recovering well Clive!
Imagine youtube in the eighties!
Next episode, Clive discusses bridge rectifiers while doing the washing up.
With high voltage and standing in a puddle?
Hi That takes be back when I started work in 1968 and the lighting was DC FLUO tube we had to stay to 8pm On overtime to reverse the DC supply to stop the tubes from going black at one end best regards
not sure if you have any videos about calculaters but the fake solor pannel on them gets me every time
2:55 glad you were thinking that too, clive! electroboom is on next in my queue! :-)
Nice video. Thanks for the rundown.
It seems to me those 630V capacitors are being slightly overvolted. However, I may build something like that, as I made a neon/mercury tube some time ago, and it was great to watch the bright red neon discharge being taken over by the mercury, but the only way I could think of to repeat the effect was to try chilling one end to encourage the mercury to condense out (I haven't tried that yet). Running it on DC hadn't occurred to me, I'll give it a whirl.
as an old-un like you I did a fair bit with neon usually claudgen always fascinating
in the description: It’s “two foot of 12mm tube” - that should keep everyone happy!
In a parallel universe, I'm watching your video called “A “U” tube neon-mercury DC migration effect (with schematic)” on Mtube.
I remember this schematic being publicized on a electronic magazine as "How to extend life of your fluorescent tubes". Of course, with less stages but essentially multiplied 220V AC to around 600 or 800VDC. Once I suggested to a friend to try it; he had a lot of old fixtures with oxidized ballasts, ancient failing starters and many one-filament burnt 1.2m fluorescent lights to maintain at his work (some government place) and not enough funds and replacements and some were very high placed. We used 8u/800V electrolytic non polarized capacitors and 1n4007 diodes. Tried one fixture, and worked. Later I heard that he modified all fixtures and was very happy. Never changed a fluorescent tube again, he retired few years later.
Now I wonder, did this setup not made the tubes darken at one end after many hours of use? I used it myself once for few months with a big tube (1m I think it was) but I didn't noticed anything.
Yes in the late 80's "electronic" fluorescent ballasts were coming onto the market, and my grandfather bought a bunch of cheap ones for the basement. Unfortunately over months the mercury would flow towards one end taking the illumination with it. The instructions were to flip all of the lamps once this became noticeable.
In low pressure phosphor coated mercury discharge lamps, ie fluorescent lamps, the current in the discharge is relatively high such to cause a high UV emission to excite the phosphors to a high light output. It relies on electron emission from hot spots on the coating on the lamp cathodes. The coating wears off, causing the shadows on the ends of fluorescent lamps. When the coating has entirely gone from a cathode the arc current cannot be maintained and the lamp is “deactivated”. In starter switch circuits the starter will keep operating. Eventually the starter may weld up and the common hot ends appear, the current limited by cathode resistance and ballast impedance. Often a cathode will go open circuit due to an emissive hot spot appearing on the tungsten cathode.
However the mercury column is still there and can be excited by high voltages, as with the circuit, or similar, you mention. Essentially a glow discharge. It will last indefinitely. But the light output of the lamp will be very low compared to normal operation and the efficacy (lumens per watt) poor.
@@ChrisSmith-tc4df The early electronic ballasts, although with an ac output, often had an asymmetric output waveform, a sort of dc offset. Eventually the mercury progressively dissociates away from the argon carrier gas from one end of the lamp.
@@99Noggin Yes, now that you mention it, the fluorescent tube that I used was kinda dim, but for its huge size (1m long tube and thick diameter; it was quite ancient at the time) it lighted well I think it was 100W or 80W rated; I got it from that friend and it had burned filament at one end. However, I changed the fixture and all few months later with two fancy circular 20W neon tubes.
You must have a castle if only for storing all the gadgets you show on the channel :D
Gas discharge tubes are quite fascinating technologies, I still want to get myself a SOX streetlamp unit (last one on this street disappeared a few months ago, replaced with a very dim LED unit) before they're all overpriced "collectors items", cos seeing the effect of heated gases on metallic elements is quite fun to watch as it happens... :D
this video remids me of a low pressure sodium lamp they had at the front of a local library, it would always glow pink at dusk when i used to go past inside a bus on the way home, but when i saw it later on it would be yellow. i always wanted to know why does it do that?
about 10 yers later the library became a demolition site, i climbed in and rescued the bulb and its ballast from sure death. its one of those U tube style lamps with extra glass envelope around everything. you can see drops of mercury in there too.
it starts a nice cosy pink but after 5-10 min it becomes a blinding yellow monotone on just 180 watts. the efficiency is truly ridiculous in how it lights up the entire yard, it must have been invented by the lightbulb god or some other major bulb deity. certainly makes other bulbs look like jars of glow worms.
the pink is from other gases used to start the arc, once the bulb comes up to temp the sodium turns to vapor and starts to emit narrow band yellow which over powers the color from the starting gas.
The pink is from neon used to heat the droplets of sodium and get them into vapour form.
Very interesting Clive! I think I've seen a few of the plug packs you mention in your description that contain this basic circuit, they usually look like standard wall warts but covered in cooling vents, am I correct? Although realistically the ones I've seen are more likely to be some kind of HV switching PSU, not a basic agricultural circuit like this, but it works and I'm impressed at the simplicity!
My memory is not so good these days but I recall that 2 inch diameter very high output 8ft (270 watts I think) fluorescent lamps used (still are?) to be used on film sets (running from the 240V dc supplies that ran the 10kW and 20kW tungsten studio lamps) with resistive ballasts. The idea was to eliminate film frame strobe effects. They would only operate when actual filming was happening and they were switched every time to reverse polarity to stop mercury migration / dark ends.
I'm not sure if they were used like that. But later there was a popular light based on high output arrays of fluorescent tubes with high frequency drivers. It was called Kino Flo.
Good Saturday morning to you sir
Very cool! But when you say "a long time", do you mean hours, weeks, or years?
weeks to months initially. It's not an instant effect.
I like your pen and inks bud. I'd highly recommend a nice copper or aluminium plate so you can draw without dents affecting your art.
I noticed that when I put a germicidal lamp near a plasma ball or Tesla coil (for short time to limit exposure) the center is a mercury plasma and the side of the glass when I touch it has violet glow where argon/krypton is excited and ionized too. In normal operation the light from argon/krypton is too weak to be notices mecause mercury is more easily exited/ionized.
I first learned about this circuit from electro boom.
Oh, the M tube! That sounds mighty marvelous! But if you turn it upside down can you use it for wambo?
This is the first time I get the capacitor + diode multiplier!
On another subject a note to self and others. When converting devices to different line voltages by changing the dropping capacitor, don’t be lazy and just leave out the bleed down resistor. I says to my self I don’t want to buy another 100 smd resistors to use only 10. Besides I’ll never get zapped I’m careful. Ahem, ouch! It sat for 2 days and still held quite a sting. 228v thereabouts.
that reminds me of a tippler used in a old tv !
Are you plundering the attic of your host? All the old stuff ...
There's definitely a lot of old stuff here.
Just for clarity, I too would call it an "M Tube".
I think a curled tube might make a interesting display with all the low spots the curl has when laid out horizontally.
Then it you took that vertical with the polarity so that it pulled the mercury up only to drain back down when you turn the power off.
On other things. When RUclips made the changes to the email alert how do I get an alert that you have posted a new video?
Thanks Clive.
NICE like gas discharge lighting
Have you had a little Xmas trip to Blackpool Clifford? lol
Always finding new ways to entertain our sorry ass's! ha ha
much appreciated m8
With the two different gasses this tube would function as a HV diode when gasses are properly separated. Be cool to inject AC and see if this theory holds water. Also Neon xformers and lamps were a light bulb nerds final fantasy. As a kid I had almost every other discharge lamp but not a large neon. So expensive!
2:56 I really would like to see the tube at its final state. Maybe set it in a corner and let it run for a while and then take a picture.
Would love to own myself, but with now €0.99(or more) /kW/h, I am not so sure anymore I can afford running it.
This is actually a pretty low power unit.
Messing about with tubes you should use Leyden Jars. You have to take your hat off to the old inventors who worked all this stuff out.
Nice circuit, must try and find some neon tubes for experiments, what diodes are suitable forthe multiplication stages, 1n4007 types good?
The voltage multiplier appears to have 4 stages so it will be multiplying by ~16 times, so the voltage across the final diodes and capacitors will be ~8x240v or 2kV. The 1N4007 has a reverse voltage of 1000v so you might get away with using 2 in series, but it would be safer to use diodes that will withstand that kind of voltage (BY203?)
Yes. 1N4007.
Very interesting, thanks for sharing the story!
Using a a high voltage screwdriver. To point at bits on an HV circuit. Makes sense.
lol you can hear the wooosh of your soup catcher as you run with your wireless mic haha
I am quite surprised that it is the cathode that gets hot. In both x-ray tubes and xenon short-arc lamps the cathode is small and the anode is huge, to dissipate all the heat from the electrons hitting it. Why is it the other way around in a neon tube?
Now I'm going to have to double check that.
Maybe because neon and mercury ions bombard the cathode.
I'm thinking that the tube in the description was gotten from Mr Mash at the Grace Brothers department store. While you were there, were you being served?
I like the way the refracted image of the schematic through the tube competes with the reflections off the surface of the tube toward the end of the video.
Nice power supply trick explained by the backstory. I've played with gas tubes of various colors and their power supplies off and on for years.
A few decades back I made friends with a neon sign maker working out of his garage and had him talked into building me a He-Ne laser and had bought the mirrors, only to find he'd moved away.
Sigh.
I was thinking about uv hazard but then I read the description. As if you would have overlooked something like that, silly me
I would LOVE to have one of those!
Are you sure mercury goes from + terminal to - terminal as per 7:38?
I thought it was the other way around!
During operation all of the gasses (including the mercury vapor) in the tube will be ionized to some extent by electron impact. The electrons (being negatively charged) will migrate towards the positive electrode and the ionized atoms (Ne+, Hg+) will migrate towards the negative electrode (the net flow of electrons is just the operating current). Of course, recombination will be occurring all along the tube (this is where the light comes from), but the mercury atoms are about 10 times heavier than the neon atoms and diffuse rather slowly by comparison. The net effect is that, when run on DC, the current (very slowly) pumps the mercury from the positive electrode to the negative electrode.
Would we double the doublers on the schematic for 120 volt mains, big Clive?
If so, what about cap values?
I have heard someone say that if you reverse the polarity on the bulb, it will slowly migrate to the other side since its DC.
I like your schematic.
All I have is a cheap circuit board version with a small transformer.
Yes, double the stages to get the strike voltage. The capacitors would only have to be rated for half the voltage, so 200V for the base electrolytics and 400V for the others.
@@BigClive thank you big Clive!👍