10KV transformer - what measures for safety. - Page 1
Forum section: electronics / projects

author: Leland_Gaunt
author_rank: Contributor
timestamp: January 31, 2025, 05:03:55 pm
content: Hello gentlemen,i will soon work on a freetime project that includes some higher voltage and i want to make sure i dont forget anything that could make a harzard. A Birkemann-eyde process is a apparatur or a machine, that creates NO2 right out of the air. Catch that gas and bubble it into water - you have HNO3-nitric acid. Nitric acid is a pretty big deal in Germany, you may only posses it up to 3% concentration, but in reality 99% of dealers wont even sell you 3%. Only to industry or shops. So the process is both facinating and useful, even if the amounts are very tiny.So for the NO2 to be created, you need a high voltage arc, in a glas, the air will be changed out by a small hose and a pump and be lead into water, where a gas washer or a simple airstone will bubble it into water.The 2 main device i saw are being used to realize this project on a small-hobby scale are neon-light-PSUs and high voltage ignitors(i think for oil and gas)For my case i ordered a 10kv/30ma neonlight transformer, just because ive seen it used in a couple of youtube videos and so i know it works, good enough for my 1st try. I will upload a picture. I have a few questions now and would appriciate if you can answer some:(there was a liitle papernote that came with the device, it basically only made clear that you shall never cross any of the outgoing wires with any other cable and always keep at least 15mm between the both 10kv lines...15mm doesnt seem much to me, just out of intuition id keep it at least 5cm....1. Device claims 10kv/30ma, but says only 240V/400ma go in -96 Watts. I think a transformer is basicylly only 2 coils. So is it 300 watts when you turn it on, but the voltage drops t3k very soon? Or will the current drop?2. Theres only 2 wires IN side, no groundwire. Is that normal? Theres not even neg. and pos. Marks on the device, not on in and out. So i guess it doesnt matter where you solder on the neg. and the pos. Plugwires.3. What about cooling? How long can this be under load? It seems people run it without break(i assume they turn it off at night at least, for sure i would)..one guy said it failed after 1 or 2 weeks..i know that the ignition transformers are only to be used in pulse mode, 1 min on, 2 min off or something alike....i guess it wouldnt be a good idea to glue heatsinks made out of aluminum on it, but maybe a cooling fan in 8-10cm distance? What life expectancy does that thing have?4.Are there any electronic (and cheap) devices that u can use to make the thing work in pulse mode, like for 15 or 30 seconds? Like these mechanical timers that you plug in the wall, but the only work in 15/30 min intervalls. I need something with much smaller intervalls. Because i would like to investigate and measure whats most efficient, it could be that a certain pulse lengh delivers much better than always on. more grams of HNO3/kwh. I cant find such a timer.5. Are there any other safety concerns that go beyond a healthy sense for safety? I will keep all cables severl cm from each other, install the device and the glas-reactors on a thick plate of wood, all on a wood table. I will plug this thing into a 3Plug-Multiplier and then use the multipliers switch to turn it on. I guess the fact that the 3xMultis cable has a ground wire doesnt do sh t for my safety, does it?heres a cheap trafo in action, dont know how many kv, but probably between 5 and 10 i guess.heres how it looks, its expensive on amazon, but the pics are better than on Aliexpress.https://www.amazon.de/Np-10000-30-Neon-Elektronischer-Transformator-Netzteil/dp/B08BPBSG13/ref=sr_1_3?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=1S6L8FMEG081Z&dib=eyJ2IjoiMSJ9.nPaOMiKyNctPY4DfpZA8kMoKIUfAdLVyBVeP26QL3E0DdyB04dMkPcn-KARSiZyFRnY5rPn5-4DnEtxSpHP2I9ObkKvaQk6sZplQs7TllnJXiYPLDTm7yQGU_t4e6xsFY1-oUezI-t2_Nl0lTKgtZFqKywulA1aKqNmiOP2muKGEPh8rj2OLPHllBjOsW_Rb1_Ts5-MrIUmdh9P-BM5alEkMwTlgqbsyGqXFkNy58KKpJiIHGh1svbytE48Fk3OgRJkpONo99TQF5gR9bqspEyK8JdwsNV0cx-n2oqMJe5nSYGpHgbUNhvMoSYvH76Pp1VdMZfGBRx0E9YPEXKuMf4tBKo6961lwazq2SUnIA9Bnho6SI3LeWDodevscBh0cpxjtxR7mJETYmCPvZSU_ahVlRT4hksYWcmOqa4IU51I10U79wpV_brJePqC6-tqH.DTFcuo7UfuxKCLzt0o7DD1FnuRpYvdrDq7aUMk2YgPE&dib_tag=se&keywords=neon+light+transformer+10kv&qid=1738342884&sprefix=neon+light+transformer+10kv%2Caps%2C78&sr=8-3and here an example of a machine with somewhat higher end components.

author: inse
author_rank: Super Contributor
timestamp: January 31, 2025, 07:57:44 pm
content: dammit, I accidentally deleted my message...Interesting project.I ran a Jacobs Ladder made from an oil burner transformer, due to the smell (cough) I had to put the electrodes into a jar, you could watch the NOx build up as brown gas.now to your questions:1. the transformer in the link appears to be an electronic controlled high frequency transformer. The spec voltage is open load voltage and the current short circuit current, I assume.The power limit will make voltage and current be defined by the "load"2. as it specifies AC for in- and output, there is no polarity to observe, the plastic housing comes without earth connection.3. no idea, just run it and watch the temperature (and smell, hehe), a fan will surely be a good idea4. there are industrial timers available that can be programmed to almost any timing combinations (Omron H5CX or it's chinese knock-off)5. don't ask me about safety, I have been operating a MOT to create Lichtenberg figures 😉Use wiring recommended for 10kV, extending the pigtails is a concern, cover joints with several (at least two) layers of shrink tube.Turning it on from a distance is also good practice.How to keep other people away from your test site - your problem...Cheers!

author: Leland_Gaunt
author_rank: Contributor
timestamp: January 31, 2025, 09:18:04 pm
content: thx.Im not planing to make the output cables longer, i might even shorten them. Then i will solder 2 electrodes on, from copper i guess.If anybody can link me to a cheap programmer or timer that i can use for small time-intervall settings, id be grateful. Just doesnt make sense to pay 100eu for it when the whole trafo was only 25eu.Im just thinking, if its made for neon-signs, its supposed to work, at least, couple of hours at a time, right?getting rid of NO2 when youre already coughing is a bit late, its a no-fun-gas.

author: inse
author_rank: Super Contributor
timestamp: January 31, 2025, 09:24:10 pm
content: Is that cheap enough?https://www.ebay.de/itm/405452847854?mkcid=16&mkevt=1&mkrid=707-127634-2357-0&ssspo=jocibj9kslo&sssrc=4429486&ssuid=UJEfguXdQ76&var=&widget_ver=artemis&media=COPY„getting rid of NO2 when youre already coughing is a bit late, its a no-fun-gas.“I know, but I told you not to ask me for safety topics

author: RoGeorge
author_rank: Super Contributor
timestamp: January 31, 2025, 10:01:17 pm
content: Yes, a lot of things can become killing dangerous with HV:- arching fire- electrocution- poisonous ozone generating- hard UV produced in certain gasses discharge- Bremsstrahlung X rays (hard radiation) when applied to vacuum tubes, etcMy advice is to not die.Other than that, there are plenty of fun experiments to do with such a device.

author: inse
author_rank: Super Contributor
timestamp: February 01, 2025, 06:30:47 am
content: Quote from: Leland_Gaunt on January 31, 2025, 09:18:04 pmIn principle yes, but your spark gap is a different load than the neon tube.Maybe run it with a plug-in power meter and adjust your electrodes to not run it at the limit.Or simply watch the temperature of the transformer and keep replacement at hand…

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 01, 2025, 12:18:06 pm
content: Quote from: inse on January 31, 2025, 09:24:10 pmthat would be great, if it can handle 240V....it says up to 5A alternating current, so it can handle 1200 watts? My device is only about 100 watts..ill order and try.

author: inse
author_rank: Super Contributor
timestamp: February 01, 2025, 12:41:22 pm
content: Hopefully it comes with a description, more than once I got devices from Chinese origin in a plain package.Had to research myself several times

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 03, 2025, 12:46:35 pm
content: ok 2 more things please that entered my mind,1. U said double shrinktube for joints, but that doesnt include the spot where i soldered on the copper electrodes, right? Ill just use lots of solder. Or should i still cover them? Theyre gonna get hot.2. This thing doesnt store any energy when its offline, does it? Coils dont store energy, only batteries and capacitors to my understanding. I still dont want to find out the hard way im wrong. Shall i open it and make sure there isnt any cap inside?

author: inse
author_rank: Super Contributor
timestamp: February 03, 2025, 02:00:16 pm
content: 1: If you feel like you have to make the electrodes safe to touch, you could slide silicone tube, the heat shrink was only to make extensions safe.2: as it says AC for the output there would be no voltage multiplier and thus no capacitor. You can verify if you turn it off and short the electrodes and notice a spark or none…

author: Haenk
author_rank: Super Contributor
timestamp: February 03, 2025, 02:03:47 pm
content: Quote from: Leland_Gaunt on February 03, 2025, 12:46:35 pm1. Solder is bad for connections that heat up. Welding, crimping or screw terminals are your only option. IMHO crimping is the best/easiest way.2. Edit: Looks like they use a transformer, as the output is AC, still: do not touch

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 11, 2025, 06:50:40 am
content: Everything works like i wished it to...Nitirc Acid production is running.a few surprises i encountered :-the power usage is only 20-50 watts, depending on how long the arc is. Longer arc= more power and also more NO2-production. Thats 3-3,5cm distance between the electrodes. Any further and it will go off eventually. But it seems a long distance for 10KV, isnt 10KV supposed to bridge only 1 cm?-my arc uses 40 watts and im using 50% on/50% off cycle. The temps are very well under control, electrodes dont even glow and the Trafo doesnt even get handwarm. thats the benefit of the relatively low power. The downside is, it needs 50 hours just to apply 1 KW/h of energy. Less than 1 cent of energy cost per hour running. Even in expensive Germany. So its made to run for weeks at a time. i dont see a problem there, the Trafo seems reasonable quality and i dont see any hazard potential..will run it all day and turn off in the night. Ill just have to wait for the timer relais now.now i just have to convert the HNO3 to potassium or sodium nitrate, before it reaches 3% concentration in order to align with ridicolous european laws.i was still hoping to get at least the 88-96 watts intake power that are printed on the PSU. I might buy a second PSU though---copper or steel electrodes doesnt seem to make any difference in my case.is there any way to increase the power or the temperature of the plasma? make it pull 60-70 watts instead of 40? Like i said, increasing the distance between the electrodes is not an option, i already did that to the point, where any further increase in distance results in random shut-offs.https://streamable.com/8kmk4ehttps://streamable.com/kpr0hy

author: calzap
author_rank: Frequent Contributor
timestamp: February 11, 2025, 07:08:14 am
content: I find the limitation on maximum 3% nitric acid to be curious. The constant boiling concentration is 68%. So, anyone with a glass pot can easily and quickly make concentrated from 3%. That may explain dealers' reluctance to sell to individuals. Surely, teaching and research labs in high schools and colleges have concentrated nitric acid. Is there special record keeping of inventory and use they must follow?Mike

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 11, 2025, 09:41:18 am
content: i have no idea to be honest whats up in schools and universities. My entry into chemics came very late, long after i left the education course.We also have a 15% limit for sulfuric acid. Pretty much the most important and useful acid in chemistry, basis for many reactions... In the motherland of pharma and chemistry, its pathetic. Its a form of tyranny, kind of a psychological conditioning, to make people constantly run into limits and no go-areas, teaching them that they are not free...thats my personal opinion ofc.you could find SOME dealers to sell you 3% acid...but good luck making concentrated one, you would probably pay several 100eus for 1 liter of 68% acid.You can also make nitric acid from nitrates ofc, preferably alkalinitrates like calcium or sodiumnitrates. You can buy these, but dealers are required to report you when they feel there might be a chance you "abuse" them...many have gotten a visit from police after buying simple calciumnitrate from Amazon, for example.

author: calzap
author_rank: Frequent Contributor
timestamp: February 11, 2025, 04:49:37 pm
content: The German government knowing when citizens buy calcium nitrate from Amazon is interesting. Is Amazon required to report such sales or does the government have some way of monitoring online purchases? Most places, the most commonly available nitrate is ammonium nitrate, which is widely used as fertilizer. I can go to any garden store in the U. S. and buy all I want for cash. In a more purified form, it’s an ingredient of ANFO, an industrial explosive. It may be that huge purchases at agricultural supply companies do get reported.Mike

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 11, 2025, 06:39:40 pm
content: the seller is required to snitch to the government anything suspicious. just read the comments on Amazon from the buyers, pretty interesting. Last time i was at Hagebaumarkt, kind of the German "Home Depot/Garden Center" i took a look at all the fertilizers, just out of curiosity, there wasnt a single one that had any serious amount of ammonium nitrate. Theres also a limit for the maximum amount of ammonium nitrate in the EU/Germany, i just dont have it in my head.

author: jonpaul
author_rank: Super Contributor
timestamp: February 11, 2025, 06:44:15 pm
content: OP still alive?(:-:)j

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 11, 2025, 06:54:05 pm
content: whats OP? is that supposed to be me?..yeah alive and well, machine is producing about 11g of HNO3 per KW/h, decent enough.The regulation and Prohibition terror is going through all parts of life here, im lucky not to be a home owner, more and more people dont even try, you maybe an owner on paper, but you dont have a lot of freedom on your own ground in your own 4 walls. The amount of BS that you have to build in your house, for "safety and climate protection" is staggering, right now it looks like people will have to change their complete heating system if it works with oil. The list of what you have to include in your house, of everything that youre not allowed, is endless.the reason is simple, teaching you the hard way youre not really an owner. Not completely. besides, how can you own something when a third party has control how much "taxes"you have to pay for it every year. Slaves are not allowed to own property.

author: tooki
author_rank: Super Contributor
timestamp: February 11, 2025, 08:17:26 pm
content: Quote from: Leland_Gaunt on February 11, 2025, 06:50:40 amThe dielectric stength of air is 31kV/cm -- but that's for dry air. Humidity and floating contaminants will reduce the dielectric strength, allowing longer arcs. And of course, once you start an arc, it is plasma, which is a good conductor.

author: jonpaul
author_rank: Super Contributor
timestamp: February 11, 2025, 08:53:00 pm
content: Bravo: we consulted in 1980s on HV HF for O3 gen. pools and hot tubs, to avoid poisonous Cl dis.The continous HV 20..70 kV at 5..40 kHz destroyued miost insultion on the transformers.Just a few PPM O3 is noticable, pehaps same for nitrous/nitric oxides?See our old friends for REAL HV":Greg Leyhhttps://lod.org/enjoy,Jon

author: TimFox
author_rank: Super Contributor
timestamp: February 11, 2025, 09:41:03 pm
content: Quote from: tooki on February 11, 2025, 08:17:26 pmAlso, it depends on the electrode shape. Pointed electrodes have a much higherlocalE field magnitude than theaveragevoltage gradient between the electrodes. In the extreme example of an isolated small sphere far from the other electrode, the field at the surface of the sphere isV/r, whereVis the total voltage between electrodes andris the radius of the sphere. If that local value exceeds the dielectric strength, it can initiate a gas breakdown.

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 13, 2025, 12:44:03 am
content: "Just a few PPM O3 is noticable, pehaps same for nitrous/nitric oxides?"im not sure whats that supposed to mean, maybe that the No2 production isnt high? Its good enough for me---i measured the HNO3 concentration in the water by titration and its even more that i hoped for. (11g/KW/h)My goal was 10% efficiency of the original reactor, im about 20% as efficient now. Creating 110g HNO3 takes 1 month though, with 16h/day power on. Not a big deal. Put the apparat where its safe and dont think about it. Dont forget it takes 50 hours to apply 1KW/h of energy, 40 watts in 50/50 on/off pulse.guys now i really need some help..i got some timer relais here and cant decipher the diagram, i have a rough idea but i dont wanna break my PSU nor the relais. Man the instruction video they made is enraging.i bought 2 relais, this one here arrived today :https://www.ebay.de/itm/135240263458man what a load of horsecrap for a non-electricianthis picture here gives me the most information, at least i hope so:now ill try to decipher, maybe one of you can correct or confirm me:-now the circel on the right with the cross mark inside, is my power consumer, thats my 230Volt neon light transformer. seems like i have to cut of the plug again. Lets start with the intake:-i cut of the wallplug again, than the pos. goes into A1 and the neg. into A2.- in A1, i screw a second wire and lead it into 15, In A2 i screw a second wire and lead it to the neg. intake of my Neonlight PSU.-the neg side of my Neonlight PSU i wire to 18is that right?i hope this thing can create pulse-cycles and not just a delayed power on or off. Right now i havent even looked into the timing department.another thing, i registered with py Multimeter that the arc is sending out a 22khz signal once its on(might be a broader band, but then this seems to be the main Fqz)...the Multimeter can register it in up to 5 feet distance, i hope its not disturbing anything in the neighbourhood.

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 13, 2025, 06:55:07 am
content: man i feel like i bought the totally wrong relais...this just seems a one-time delay relais for lighting, etc.The 1st relais i ordered, the one from the beginning, takes weeks to arrive so in the meantime i ordered this one...should have looked closer what it actually does i guess.

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 20, 2025, 04:55:34 pm
content: hey guys, its me again, things running good now, i have a timer, i have 2 PSUs now with 2 archs running at once.Can somebody maybe give a good guess on how the humidity in the air would affect the arch? Atm each arc is an inch long and consumes 40 watt. Im thinking about factors that i can control and that might make the reaction more efficient. I can easily make the air that gets in the reaction chamber 80% or 20% humid...i just have no idea how it would effect the arch and its temperature.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 20, 2025, 06:40:38 pm
content: Then go ahead and experiment, set one unit to 80%, the other to 20%, and measure which one produces better. And so on, try other percentages too, and see where is the maximum, and if it worth the effort of altering the air humidity.My wild guess is more humid might work better, but I never tried in practice.

author: TimFox
author_rank: Super Contributor
timestamp: February 20, 2025, 07:35:31 pm
content: Two abstracts for actual data on humid air:https://www.sciencedirect.com/science/article/abs/pii/S0168583X11010135andhttps://www.nature.com/articles/183174a0Humidity seems toincreasethe breakdown voltage, compared with dry air.(Check with your local library for full articles.)

author: RoGeorge
author_rank: Super Contributor
timestamp: February 20, 2025, 08:20:09 pm
content: Another way to lower the breakdown (arching) voltage in air, and thus to get longer sparks, might be to reduce the pressure. I don't know if longer sparks at a lower pressure will be beneficial or not.https://en.wikipedia.org/wiki/Paschen's_law

author: TimFox
author_rank: Super Contributor
timestamp: February 20, 2025, 08:49:45 pm
content: The Paschen curves shown above are very important to understand.Note that the horizontal axis is the product of (pressure) x (gap), while the vertical axis shows the breakdown voltage.The curve for each gas shows a broad minimum, which rises quickly for vacuum on the left, and slowly for high pressure/long gaps on the right.Of course, these curves are valid for a uniform electric field, such as that between two flat electrodes. Things are more complicated when one of the electrodes is a sharp point, where the field is much higher near the point.In traditional high-voltage measurements, large spheres were used to make the measurement gap, where the large radius gave a reasonably uniform field between the electrodes.The gap was reduced (carefully) until the spark jumped, to measure the voltage between the electrodes.You can see equipment like this inThe Bride of Frankenstein(1935) andYoung Frankenstein(1974).

author: inse
author_rank: Super Contributor
timestamp: February 20, 2025, 10:41:12 pm
content: As i understood, the goal is to produce a maximum concentration of nitrogen oxide - the impact of pressure and humidity on that may be different from arc length alone

author: calzap
author_rank: Frequent Contributor
timestamp: February 21, 2025, 08:50:00 pm
content: The gases in the Paschen curve diagram in Wikipedia are nonpolar. What would the curves look like with a polar gas like water vapor, carbon dioxide or monoxide, nitrous or nitric oxide, sulfur dioxide, etc.? How about a conductive gas like mercury vapor?Mike

author: Leland_Gaunt
author_rank: Contributor
timestamp: February 28, 2025, 01:52:03 pm
content: well its me again, i finished my tests with dry air (under 30% humindity, cant get it completely dry, its alway between 24 and 29%), didnt do much, but increase power usage about 10%...havent tried wet air yet.but thanks for your links, i will look into that. Thing is, it always takes half a day until i see if a change that i made, actually affects the efficiency. because its such a slow process, there needs to be a certain amount of acid in the bottles, before i can make a titration and actually measure a significant difference.i came over another website where somebody altered the frequency of the arch (meaning the output AC)?? My arch (or the output side of my transformers) seem to put out a 22,7KHz frequency. I can measure that with a multimeter up to 1 m distance. Changing that frequency- i have no idea how its done- seems to have drastically increased efficiency for one guy. He had a much bigger and more proffesional machine, but whatever, how can i change that output frequency, and idea?greetings.