hm the invisible ink only sounds like a deterrent for people who don't know what they searching for/looking at. For people that aren't even there on purpose or something and just took a wrong turn xD

@@Ramog1000 Crash wreckage would most likely be found by low level infantry and they wouldn't call in an intelligence officer to the scene if it didn't look like there was anything useful

The level of detail in your reply is astonishing and great to read, you sir are a legend

Wow !

I question your story because they are not meant to run on D.C. I doubt military is going to use a questionable method to run electronics especially when it's so simple to supply it w a.c.

"Effective irradiances observed at distances of 500 mm from the arc were in the range 0.045-2.2 mW/cm2. At these irradiances, the allowable daily exposure times are just 1.4-67 seconds, which are extremely small compared to the cumulative exposure time over the course of a single day, indicating that direct exposure to UVR emitted during arc welding of cast iron is quite hazardous. Therefore, if workers engage in arc welding of cast iron without taking appropriate protective measures, even short-time welding will result in exposure to dangerous amounts of UVR." -Comprehensive analysis of hazard of ultraviolet radiation emitted during arc welding of cast iron, Journal of Occupational Health Volume 62, Issue 1 Jyunya Takahashi, Hitoshi Nakashima, Nobuyuki Fujii, Tsutomu Okuno 03 December 2019

@@TheRealFlamingNinja interesting read! Strange material to choose though, cast iron isn't easily weldable. A lot of welders I bet go way over the limit of exposure too

@@ooddrr99hh I think pure iron is used as it's a sort of "best-case", the authors go in to detail about which fillers emit the most UV and it seems the closer to pure iron the fillers are the lower the emissions. Possibly also just for the sake of clarity too, steel != steel.

@@TheRealFlamingNinja cast iron is a bit of a misnomer. It contains a lot of carbon, but I'm not sure 2 batches have the same amount. Much more than carbon steel. That said, as you say, steel comes in many flavors as well.

the uv light might destroy fridge plastics!

Intelligence isn't everything, being polite and positive carries just as much value in daily life.

Glad you like it, sulfie! I bought the 230V version just to document the flickering :D Thanks for the early watch.

Mercury vapor bulb been around for 100 years nothing special here.

Exactly! I am subscribed to him and he introduced this GTL3 to me :D Thanks for watching.

@@brainiac75 Love the videos. 👍

@@brainiac75 3½ years ago. He's got a video explaining it to the utmost electric detail. You're going more chemical on it, which is a very good supplement to his video... You should probably link to his video about the bulb as well, so that it's fully covered.

Probably mild alpha emitter, with a little bit of others from the decay chains, because making a barium/strontium oxide mix that is also other acintide free is pretty hard, so it will be slightly radioactive. Glass will keep it safe though.

You mean from naturally occurring radioisotopes? Might be tough to measure, especially through the glass.

@@Scrogan alpha particles certainly would not get through the glass.

Naturally occurring barium and strontium aren't radioactive. I think you're mixing it up with thorium. Thorium dioxide is also often used in thermionic coatings, however.

Guess it depends on how you look at it. The final output is most similar to a fluorescent tube without the fluorescent coating but they have two filaments. Incandescent only have one - like this 'hybrid' ;) Thanks for the early watch!

@@brainiac75 long fluorescent tubes have one on each end to help ensure the entire tube is evenly illuminated - since that's not a requirement for these tiny bulbs, calling it a half rather than a hybrid is certainly accurate :) (Otherwise, a normal fluorescent tube would also be called a 'hybrid' by your logic since they have the same startup procedure and components)

The normal silica glass itself also absorbs most of the UVC from what I remember, so another layer of protection. You would be getting the tanning UVB tho without the coat. Those UVC lamps from my memory require special glass, quartz one if I'm not wrong.

This has nothing to do with fluorescent lamps - it lacks fluorescent coating. It's a UV lamp.

probably also saved by the glass too, if I remember right normal glass absorbs UV too.

Depends on the Qrr (reverse recovery charge) of the photodiode but yeah, good idea :D

Common practice for asians to sell death traps like this without a single care. You can tell from the writing on the bulb that this one's from China, which explains everything.

Interesting. I haven't tried the banana test myself but certainly an easy DIY test suitable for a video on my channel ;) Maybe it needs the ozone-generating 185 nm UVC to work? I think the one I have only emit the typical 254 nm but 185 nm is blocked by the glass. I smell no ozone from it.

@@brainiac75 www.lighting.philips.com/api/assets/v1/file/PhilipsLighting/content/fp927903404007-pss-global/ADAM-20151211161941374%40en_AA.pdf this is the other lamp i use, the datasheet seems to indicate that this is also 254nm so im not too sure what is going on here, did test with both lamp for like 10 minutes eachtwo of that small bulb did very little to the banana peel, while the philips makes drastic change

@@brainiac75 I got those bulbs from China few years ago. They would let you choose between versions with or without ozone generation blocking coating.

​@@brys555may I ask how to order and what's the comparitive cost? Is it as cheap as it is built cheaply?

Haha, that's an odd incandescent bulb. Haven't heard of that before :) Thanks for watching!

70 MHz (megahertz) is a very high frequency to be radiated by an incandescent bulb (never even heard of high frequency RF being emitted by an incandescent bulb). But this might be in the realm of RF weirdness that I have no idea about

@@YSPACElabs surprised me too. Was seeing hum bars on analog TV channel 4, that just seemed to come and go at random, but mostly at night. Was just luck that the TV was on when I switched the light on. Put the bulb into a desk lamp and it was still radiating RF when on. Folded filament clear antique style.

@@garygough6905 probably RF weirdness with some sort of parasitic components. Probably has to do with the parasitic inductance and capacitance that form an lc tank, that is somehow fed by 60hz AC. But I would think the resistance of the filament would dampen the wave quickly. Also, if my theory were correct, all incandescent bulbs would radiate high frequency rf.

@@YSPACElabs Yes. While , most of the time, parts are treated as purely resistance, inductance, capacitance in reality everything has a value in all characteristics. Two parallel wires are capacitively coupled, both are inductors and as it is distributed over the length shows a characteristic resistance ( impedance ). Early radio operators, ( 1920s ) would have been very familiar with a coil of wire having a resonant frequency. Adding a seperate capacitor did lower that and at the same time narrow the response. Every diode is a noise source. Every junction between two different metals is a diode. In early tubes a single resistive wire was both the filament and the cathode, so the tubes gain varied across the length of the tube as the filament was also a voltage divider for the filament heating power, but also the cathode voltage at any point was the sum of the intended cathode voltage and the ( much lower ) filament voltage. Actually everything in a tube interacts with everything else, they are fun to play with. So add an indirectly heated cathode to correct that issue , then there is the capacitive coupling between the anode and the control grid, add a suppressor grid. Then a screen grid. Ah well, misspent youth. Anyhow back to the weirdness at hand. The bulb has filament supports about 1.5 inches apart with the filament zigzagging between the power leads and upper and lower supports several times. So several inches and probably enough inductance and capacitance to actually have a resonant frequency. A normal bulb with a short filament isn't going to be much off of a pure resistance ( have seen them used as dummy loads for lower frequency transmitters ). This thing was a warm glow, decorative bulb. I'm 600 km away from where it is, so no pictures right now. Just a curiosity anyhow.

That was a major flex if I've ever seen one.

Thank you very much, Ronsku! Much more to come.

Most likely you have been killed and defibrillated by a single shot/shock.

@@georgkrahl56 It doesn't work like that. But maybe I missed a beat.

@@user255: This was a joke. Meaning, be happy that you did survive it. We have had a severe electrical accident at the U of Berne with a flash-lamp pumped dye laser. The capacitor was (physically, not by uF) much larger, but charged to 20 kV. We could not determine how the PhD student managed to open the steel doors, defeat all interlocks and did come to the insane idea to use a standard multimeter to contact the porcelain insulators. The student was found lying in the corridor outside of the lab. He somehow did survive it, but his ECG is permanently abnormal now. Our professor had the guts to bring the multimeter to the repair shop. Answer (looking at the shattered smoking remains in the enclosure) was something like "I fear we cannot do anything".

not scientific but.... banana peel test

@@TonnyCassidy 10W, so likely half the power goes into parasitic loss in the uncoated length of the filament, so 5W of actual energy in the glow discharge, which pretty much makes it about a third the output as a T8 12in UVC quartz linear lamp. Roughly the same losses in there, and that is 18W, and the linear tube has a bit more loss, because of the long spacing of the electrodes. But concentrated into a really tiny area, almost a point source, so will be much more effective at close range.

I mean, you can use the spectrometer footage and use ratio to visualise how bright it is. Not the best method, but could give the sennse of scale. There are 4 peaks of visible light there that are 20, 8, 32 and 14 pixels high, so combined they'd be around 74 pixels. The UVC peak is 813 pixels high, so the invisible UVC is around 11 times brighter than what we see on the video and considering the camera catches it in the daylight in some shots, it's bright AF.

Yes. You can take the phosphors from a broken fluorescent lamp, and coat the UVC lamp with it. It will light up brightly. I already made a little prototype, when i have a 'nicer' version i will make a video about it and post it on my channel. The UVC light does not do much with phosphors typically used with UVA/blacklight - those don't respond well to the short wavelenght UVC.

That adapter could be very dangerous.It could have a capacitive dropper with no galvanic separation.

US plugs have holes, that's a Chinese plug, same thing pretty much but uses 230V I think? Been a while since I've read into it.

@@fluffball1415 In the US standard the holes are specified but optional.

The plug itself may be an arc hazard, but typically only the cheapest of plug/cords are not rated for 300VAC ( from my experience) and I've used them extensively at 277 without ever having an issue ( lab enviornment where it was legal of course)

Thank you very much, JustPyro. Much more to come :D

Phosphorescent coatings glow in the presence of UV. Thermionic coatings, probably not.

One of us!

Oh please.. Mercury vapor light have been around for 100 years... They just use a special glass to block the uv to make it safe. The frosted coatings on later versions convert the uv into red light to make the bulb white in color versus green. Welding puts out uvc radiation.. it wont kill you or give you cancer. Just dont look at it hah. The burns from uvc on the skin isnt that bad either.. a minor sunburn.

Thorium actually has many uses, Thoriated welding rods, mantles for gas and other flame lamps, filaments in discharge tubes, and it goes on lol

Yeah, that weird powder finish on the filaments made me think of those old (still used) thorium mantles for some kerosene & petrol lamps (c/o Technology Connections - love him and Big Clive!).

It's not just UV that is dangerous to the retina but also long term cumulative IR exposure.

Did you make a video?

Interesting. The electronic dimmable ballasts I've tested for Flurescent bulbs typically ran from 40-100 kHz ( depending on the dimming level).

@@onradioactivewaves - They might, but I bet those lamps are much smaller. Frequency requirements for bulbs (to obtain max bright) vary depending on size and wave propagation inside the lamps through the mercury vapor and this is not my area of expertise but I would certainly look it up or run some tests with a signal generator and a strong power amplifier (like a PA or DJ amp) into a transformer to make variable frequency AC at sufficient power to light lamps and test which frequency gives the highest lumens... and depending on the size of the lamp, it varies from bulb to bulb. Just remember that a good 500 watt to 1kw DJ audio amplifier is your best friend in conjunction with a transformer and a signal generator to create AC of any voltage or frequency you need for a test. I did this testing switching power supplies for our projects some years ago and was able to separate the stable and unstable supplies on the market. MeanWell power supplies are very good which is why they make them for others to private label and are the most copied switching power supply out there. But that test jig I described you can power and test about anything and feed it 50 or 60 or 70 or 100hz or even feed it 400 hz like aircraft or 800 hz like they use for the AC in some of the newer airplanes so you can see how your equipment will behave with that kind of power. Cardboard boxes either thick or doubled make good blast shields for exploding parts LOL 💣💣🔥🔥 😜👍

@@KlodFather you're correct, I was testing ballast for the at the time industry standard T8 4 foot loot long fluorescent bulbs. I my worknwas on the control side of things, so my knowledge of the physics of the light bulbs was more indirect learning. I can tell you this though, that the important factors were efficiency and longevity of the bulbs over maximum light output. Those bulbs could last a very long time, in the 10s of thousand s of hours. Striking the bulb was said to be on the order of ~ 15 minutes of use in terms of fatigue/ damage to the bulb ( different types of start had different effects of course) and the cost to replace a bulb factors in to those equations of how to design and operate the light bulbs. I can see that these bulbs here have a different purpose and that efficiency andongevity are not necessarily an end game factor ( although obviously you want the bulb to last say 400 hours versus an unacceptable 400 seconds) . Thank you for sharing your knowledge on the subject, I'm certainly am not well educated on the physics side of arc lighting.

@@onradioactivewaves - You are sharper than you think you are... The more I learn the dumber I realize that I am LOL. Just remember that trick of using a high power audio amp to drive a transformer at any frequency you desire and you can run anything with it even in crazy terms. Guys always poo-poo things like that but its because they do not really understand the electronics or what the hell is actually going on in that equipment. Most electronics, even the junk is designed with a lot of slack in it and you can push things to work in ways never intended in the first place without consequence as long as you are not stupid/foolish and cover your bases and asses LOL. Also 3/4 plywood is what I call a level 2 blast shield when testing electronics for flying parts. When you turn silicon and metals into plasma directly, they tend to go off like a firecracker or worse.

@@KlodFather my real forte is breaking things, hardware and software , which is why I got into testing. Learned how to deal high voltage ( technically not depending on who's definition, but high enough to kill you) and learned how to build things in the lab. I had plenty of things at my disposal which really helped, and a big help is knowing both hardware and software. Just as you said though, the more I've learned, the less smart I feel. I think everyone is capable of learning though,the big difference is if you're doing it because you "have to" or if you're doing it out of passion of curiosity, that's where the difference between being and being fun exists. Also, being able to fail over and over, knowing when to make a change, attention to subtle details, learning how to learn, are very helpful in succedding in learning and accomplishing tasks. Knowing when to listen to other peoples knowledge and experience is another very important tool for learning, which is why I try to not ever dismiss anyone's knowledge, even if it goes against what I would think is correct, you have to be willing to challenge your own beliefs. That is why I enjoy reading the discussions such as in this video.

That is interesting, I've only used a light meter. You could also use a photodiode or photoresistor if you had one available ( I had all of these things at my disposable, but followed a pre-existing procedure)

yeah they need a form of current limiting, wether it be by a cap or by a LV driver I've only got vaccinated twice as i've never been scared but because of the covid discrimination (covid pass and other BS) I even got omicron once and it was just like a week of a weak not-100%-well feeling with some coughing, the vaccines aren't even made to deal with omicron aswell and it was over a year ago that i had a vaccine (july this year is when i got corona first time lmao, i mean i always went to work etc and it still took that long)

@@tripplefives1402 they're usable for much more than covid tho

What will you use it for ?

The voltage across the electrodes is changing, so as it drops below the threshold voltage, the electric field strength isn't high enough to cause the ionisation of the gas, so yes, I would expect current spikes too when the gas breaks down. But I suspect the thermionic coating will lower that threshold voltage significantly, than without it. So conduction is likely to occur for much of the input signal cycle.

Glad you like my videos, Tom! Much more to come - I learn from researching for the videos too :)

Thanks! I don't know the purpose of the plate. Some speculate it is a reservoir of amalgam/mercury to keep the mercury vapor steady?