Arcs, Sparks and Jacob's Ladders
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- Опубликовано: 28 окт 2023
- For Halloween, here is a quick look and electrical arcs and discharges, much like you often see in the old Frankenstein movies and the wonderful TV shows from the 60s like The Munsters and The Addams Family. Also included are many of the things we use sparks for in our everyday lives including spark plugs, lighting gas stoves, flash tubes, fluorescent lights, neon bulbs, and arc welding.
Although there won't be a lighting bolt with giant sparks making a monster come alive in the video, hope you enjoy it and Happy Halloween! 
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Excellent video. Thank you.
Well thank you! So glad you liked it and and I really appreciate your comment!
Excellent set of experiments, beautifully photographed and explained.
Thanks! Really appreciate that! I certainly had fun doing it!
Love when you put out video's. Always learn something.
Thanks so much! More videos on the way!
Beautiful demonstrations !
Thanks! The part that I thought was most beautiful was some of the colors and large dancing arcs when it was cutting though the glass.
Brill. That was really interesting and informative. Thank you.
Your welcome! So glad you found it "interesting and informative" - thats what I'm always going for.
Years ago I was at a HV demonstration for linesmen (I'm not and never have been one) where they showed the performance of various insulators. They did the plate of glass demonstration but things didn't quite go to plan. It didn't reach around the glass and start chewing its way up the plate. There must have been a flaw, possibly even just an inclusion, that gave the arc something to conduct through and it settled mid way on the plate. The plate only lasted a couple of seconds before it shattered probably from the heat stressing it.
That must have been a memorable demo - sure showed a slight manufacturing or material defect can have devastating effects. In my demo, the end the crack extended all the way up in my glass plate and after I dismounted it, it split in two. Sometime I want to try with a higher voltage to see if I cant punch right though the glass....
Thanks for the nice walkthrough of the so scary sparks we've mostly seen in old horror movies!
Your welcome! Those old movies are wonderful!
Love this video. It looked like a lot of fun to do. I really like the saw blade demonstration it reminds me of spark gaps on some circuit boards. I have a old video talking about spark gaps and I thought they were neat. I wish the video equipment could do justice for the neatness of the arc as my video equipment is still not great, but that was an even older camera. I could smell that ozone at the end of your video when I seen all those pretty purple arcs on the glass. I used to work in an environment where a lot of ozone was generated at times. Fun fact: plastic film before its printed on or before can write on it has to be treated. High voltage is directed through the film while it is being wound up into a roll. We used somewhere between 5-10KV and around 10KHZ. It was a pretty purple line across the web. Usually had granule filled ceramic rods across the sheet with the HV attached going through the sheet and the roll behind the film grounded and usually had an epoxy or ceramic coating.
It was! I never even thought about circuit board spark gaps but your are right. I will definitely look though your videos for that one!
Camera equipment - my camcorders where not nearly sensitive enough to get good video of the very dim blue corona. For that I used my Nikon D810 DSLR cranked up to ISO 12800 and for some shots, ISO 25600 (normal photos are taken with ISOs in the range of 50 to 800). Camcorders like the ones I have cant even come close to that. I also needed to add some noise reduction when editing the video because those high light sensitivity settings produce really noisy videos.
I don't know if I said it, but the corona setup sure produced a lot of ozone! (Well I did say it but not sure if it survived editing).
You really intrigued me with the bit about treating the plastic film! I'm racking my brain as to why! Only thing I can think of is to make it stick better when stored in a roll, but you indicated it was for printing. Xerography uses static that way to attract the toner, but that wouldn't apply to writing. So why was the plastic HV treated?
One of the points of the video was to show that we use sparks and HV discharges for many more things than we normally think of - not just for horror movies. Your comment here so nicely adds to that which things I didn't think of or hadn't heard of. Thanks for pointing them out!
Yes 🙌 another one from one of my favorite channels!
Thanks!!!! More to come this fall!
You always have great content.
Thanks again! I really liked creating that video!
Thank you sir, that was illuminating and sparks my flame to continue studies
Cool! What are you studying? EE? Physics?
I got a "shocking" safety lesson when I checked a Tesla coil out of the college physics lab in '79. My goal was to built a Jacob's Ladder for Halloween and It worked! The problem was that, when I went to move the leads some (while it was running), I got quite a shock right through the insulation on the leads (right through my hands and across my chest)! It wasn't until I shut off the lights in the room that I saw the corona "glow" along the length of each lead, much like your saw blades at 10:25. It had never occurred to me that the insulation might only be rated for 600 or 1000V. Obviously I survived, but my chest was sore for days afterwards!
There is a similar comment below from someone who was using a neon transformer. In hindsight, its surprising or lucky that I didnt get zapped from a defect in the insulation of HV cable in the old CRT TVs I used fix when I was in high school. Of course that cable was insulated for 20 to 30kv. It must have been quite to shock to leave your chest sore - I have never experienced that.
I wonder if some of the corona in the case of your Tesla coil wires was not just under-rated insulation, but perhaps the result of the displacement current though the insulation due to the high frequency AC field ionizing the air?
The glass demo was great. Everything is a conductor if the electric field is high enough. Most glass made today is soda-lime glass, which is made from a mixture of silica (aka quartz, SiO2), sodium oxide (Na2O), and lime (calcium oxide, CaO) along with small amounts of other oxides (magnesium, aluminum, iron, titanium and potassium, if you believe Wikipedia). Both sodium and calcium give strong emissions in the yellow/orange region of the visible spectrum when they get hot enough, and the arc is definitely hot enough.
Reminds me of a demo I saw at the Corning Museum of Glass when I was a kid (late 1960's). They had a Vycor (glass that is mostly quartz with just a bit of aluminum oxide) disc rotating (about 1 rpm) between two spherical electrodes that were spaced about half an inch apart. The disc had two holes in it 180 degrees apart. When one of the holes lined up with the electrodes, an arc would jump between the spheres and slowly get stretched out to about 6" long before extinguishing. The coolest part was that it was interactive, so the visitor could turn it on with a push of a button and it would reset after a full revolution. (I would have stood there pushing that button until closing time, if my sister hadn't dragged me away.) Sadly, the next time I was at CMoG (2006) I couldn't find the demo, so I suspect it did not survive the flood of '72. The point of the demo was to show that Vycor was much more heat resistant than ordinary glass (higher melting point and lower coefficient of thermal expansion) and much less conductive (essentially no free ions compared to soda-lime or even boro-silicate glass). I don't think Corning makes Vycor anymore.
Thanks! You just confirmed something I was speculating about and actually edited it out of the video because I wasn't sure - the yellow when going though the glass sure looked like sodium - so based on your comment I guess it was!
The demo you describe - how interesting! I have never seen a demo like that but I guess you need that Vycor glass you mentioned or it would fail just like my plain old glass. The interactive part must have been amazing. Its funny - not sure if I would ever think to go to a glass museum but I would for that exhibit!
My similar memory from childhood was when we lived Germany for a few years in the early 70s. If you ever visit that part of the world and are in the Munich area, the Deutsches Museum is one of the most amazing science museums I have ever visited with lots of interactive exhibits like that. Like you, I could have stayed till closing!
@@ElectromagneticVideos Hope I didn't give you the wrong idea about CMoG. There were quite a few other displays of interest. There were live glass-blowing demonstrations (when glass was held in the torch flame, the initially blue flame developed the same bright yellow-orange glow as seen in your arc). There was another interactive display I remember where you could crank a handle that raised and dropped a sledgehammer on some particularly tough glass (maybe a precursor of Gorilla-glass?). They also had a failed mirror blank (the steel mold melted) for the Hale telescope (largest in the world from 1949 until 1976, 200" in diameter and about a foot thick with a honey-comb stiffening pattern molded in, made of borosilicate glass, aka Pyrex). I think they got it right on the second try and it has been in service ever since. Another display that foreshadowed things modern was the optical glass display, where they had a couple of scenic postcards that could be viewed through cast glass blocks. One block was ordinary window glass and about a foot long, showing a dim blue/green image of the post card. The other was high purity optical grade glass with the same post-card sized cross section, but about twenty feet long and the view of the card was crystal clear. Next to that was a mile long spool of fiber, made from the good glass, with a light shining through it (so, yes, the beginning of the fiber-optics industry). The boring bit (for me, at that time) was the ancient glass collection (thousands of beads and bottles, some going back several millenia).
@@robertlapointe4093 Now you have convinced me to visit if I am ever in the area. Not too far from me as the crow flies (200km) but a longer drive due to Lake Ontario being the way. I would enjoy the same things you liked and similarly be bored by ancient beads :)
I read somewhere that Corning had developed Gorilla-glass way before cell phones - I think that had a small scale use for it - how lucky they were to have developed it - they must be making millions or billions!
Back in 1970, I was in High School then and tinkering in my garage with a 9000 volt neon transformer. By accident, the two wires I had positioned jumped from their spot and each landed on my thumbs. Not so good for the heart. My vision turned off, what seemed like minutes, and I could not let go at first. I was sitting at a old kitchen table and I finally pushed with my legs to move outward and get loose. That event really scared the heck out of me. Note : I still have that transformer but with a ton more respect for it or anything with high voltage. I am just glad it was not high amp like microwave transformers have or I would not be here speaking about it. The neon tranformer was in milli amp I believe. Way less than a microwave one. 68 now and arranging for a new garage I bought to be placed at new house we got , 13 miles away from the old one. I want to make it insulated and into a lab then I will experiment again with many things. Trying to beat winter on just getting it here.
"My vision turned off" wow - as a kid I had a very similar experience when a somewhat hidden live cable in our yard touched near my ankle - my hands were grabbing a well grounded metal windmill tower - voltage was real 220 (we were in South Africa at the time). Did you see anything when your vision shut down? I vividly remember black with swirling colors like the colors you see when closing your eyes. I wonder what the mechanism is - the only thing I can think of the brain been flooded/overloaded from signals from the nerves in the lower body.
Yea - those types of currents are (10 to 20mA) are generally survivable. The 1A available from microwave transformers is not!
New insulated garage/lab - what a great project - know exactly what you mean about trying to beat the winter. Hope you post some videos of your lab experiments when its setup!
Been a long time but I think I remember some yellow streaks a bit. Money is very tight now and the garage/lab may sit all next summer unless I find a way to add to my income. I am retired and a few physical issues but not serious enough to make me bed ridden. Last year I won a digital osciloscope worth $2200. Nice addition to many other gadgets and tools, master of none. 😶@@ElectromagneticVideos
awesome
Thanks!
you make really interesting content@@ElectromagneticVideos
@@leetucker9938 Thank you so much! I really enjoy making them - it has been a great excuse for me to redo experiments I last did years ago or some (like the speed of light one) that I always wanted to do!
I remember watching some of these movies when I was a kid around Halloween time. At the AC/DC electronics class I took back in 2013-2015 we watched some safety videos on electric shock and arc flash (as a journeyman, the thought arc flash scares me more than shock) One of my instructors then made a Jacob's ladder using a 15kv neon sign transformer. The purpose of the Jacob's ladder was to demonstrate the unique characteristics of arcs and the importance of current limiting means such as the ballast in arc lamps (fluorescent, neon, xenon, mercury vapor, sodium vapor)
I loved the glass experiment you did, what most people think of as an insulator is really more or less a conductor with a very high resistance such that for most intents and purposes it prevents current from flowing unlike the copper and aluminum used for electrical wiring. No known substance is a perfect insulator or perfect conductor.
Neat to hear you had an instructor who did demos like that - I always find actually seeing something make it much more real that just in a book. You mentioned the unique characteristics of arcs - something I didn't mention in the video was the negative resistance characteristic of arcs and how they were used as radio transmitter oscillators in the early days of radio. It was to see if I can duplicate that in some future video.
I completely get your comment about arc flashes - luckily I have have experienced a significant one - but I can sure see in your line of work the dangers when almost unlimited currents are available to vaporize and hammer anything nearby. An electrician neighbor told be of a giant bus-bar vaporizing in a nearly plant where a breaker failed - yikes.
You make a great point about insulators actually just being very high (but not infinite) value resistors. I'm always wary of HV cables like those in old color TVs where 30kv or more feeds the picture tube. Never want to find out what happens if the old insulation has a pinprick hole!
Waited so much for your new video. Thanks.
Thanks so much! It was a while since the last one but more to come between now and Christmas!
I remember watching one of your videos earlier this year and I think you replied that a family member once could see the slight flicker of 25hz in their home in the 40s or 50s?
Anyway while doing videos on arcs and sparks, with your previous background in electronics I was wondering if you had the equipment and ability to recreate some of the oddball frequencies that were used in the late 19th and early 20th century before we finally settled on 60 hz (or 50 if you happened to be in Europe) Besides 25hz, there was 16⅔ for trolley motors, 33, 40, 66.7, and finally 125, 133 and 140 were used to reduce flicker during the carbon arc era. And 400 hz is common on aircraft and other military equipment.
It would be interesting to see how a Jacob's ladder would behave with some of these weird frequencies. A VFD on the transformer primary might work, I'm thinking.
I remember that discussion! And your comment here is the perfect setup for a future video inspired buy that discussion! Since that previous discussion - and I think you suggested a VFD as well back then - I have since purchased a couple of variable frequency drives and plan to do just that. However, before that I want to use the two HV transformers to do a video demoing why we use step-up/step-down transformers for long distance power transmission because I am a bit concerned that the transformers may not survive some of the different frequency tests.
The lower frequencies will require proportionally lower max input voltages so as not to saturate the transformers. So will probably limit things to 25 or 30Hz at 60VAC. So maybe for an apples to apples comparison, will narrow the Jacob's Ladder gap to work with 10kv and do all frequency tests at that that voltage. And then - and here is the risky test - I want to try doubling the voltage and frequency (to prevent saturation at the doubled voltage) to see if I can get 40kv out of the pair of transformers. My guess is the insulation should have a significant safety factor built in and survive that, but who knows!
And as an added bonus from having the VFDs, also will do a video about three phase - should be able to hook up an incandescent bulb to each phase and show how the voltage and power peaks moves from phase to phase over the course of cycle. Thanks for suggesting I looking to VFDs back then - I had no idea how cheap they had become!
Nice demonstration, with the glass between the 2 pieces of saw with the Corona effect, how is the current draw compared to without the glass?
I didnt actually measure it, but for the initial Jacob's Ladder arc, the power delivered to the transformers was fluctuating from 150 to 300W. If we assume the 300W occurred when the voltage was at the full 20kv, that means the arc had a current of 15mA. When the arc was shorter with the saw, we would expect a lower voltage across the arc (once established, the arc becomes a low resistance current path) and a higher current limited by the magnetic shunt in the ignition transformer. So my guess is the current with the saw would have been around 25mA. Now add in the large glass and resulting corona, the current would be way less with the voltage at the full 20kv. At 20kv, 1mA would result in 20W of power consumed by heating + ozone and wind generation. There was no noticeable warmth at all on the glass when I removed after the experiment. So my guess is 1 mA or less type current flow for the corona demo. Would be neat thing to measure directly but a bit difficult since the meter would have to isolated in a HV insulator.
@@ElectromagneticVideos , thx for the quick reply. I know from a Arc welder, when the arc during welding is bigger, the more current is draw, so your calculations are what i expected. Grtz
You could show/explain us the difference between stone and piezo sparks in lighter...
A piezo video is in my plans!
Nice !@@ElectromagneticVideos
try copper tubing for conductor rods on a jacobs ladder, ime there was a significantly different arc effect produced
You have me intrigued! Just looked at your video (which I think shows wire rods?). So what did you observed that was different? I can think of two effects: 1) the larger diameter leads to lower electric field at the rod surface and 2) the additional copper keeps the rod cooler . You are also using a much higher current transformer compared to my transformers limited to low currents which also makes a more stable arc.
@@ElectromagneticVideos the jl in my video was pretty standard, unfortunately I didn't take video of the one with copper tubing, as I recall, the tubing didn't produce a climbing arc but more of a fountain or geyser type of arc, the corona resembled fire more than it typically does but of course there's several other factors that I cant remember as it was years ago I just threw it together with my sons one evening.. anyway I thought yould be the right guy to try it out, just allow for plenty of clearance above your device and maybe keep an extra step away than you normally would, personally I prefer to use a remote controlled wireless ac outlet and also an easily actuated wired switch at the device (in case the remote fails)
- id be building one right now but I haven't had any hv transformers nor the time to go scavenging, id love to see what you're thoughts are on it, you clearly know what you're doing so I don't have to worry about contributing to someone's death over a little tweak of the ol' jacobs ladder lol
-feel free to reply to me here or on that vid I linked and you sir have one more subscriber! ⚡⚡
@@Invisus_Letum I definitely will try it - I do happen to have a number of spools of small copper tubing that I was planning to use for antennas someday, but there is more than enough to use for a Jacobs ladder as well.
Safety: I do try to emphasize safety in videos where it is appropriate but unfortunately many people on youtube just skip to the "interesting" parts. Not sure if I showed it but whenever I deal with HV, I always use a two-handed dead mans switch (one switch for each hand, both must be on) a good distance away to prevent being anywhere near the danger zone. I do have similar concerns as you as far people copying and not knowing what they are doing - my feeling is the best thing to do is so show how to do things safely and hopefully provide info not found in many of the crazy youtube videos.
Glad you subscribed and hope you enjoy my other videos. Its quite a range of engineering, technology and science stuff so dont expect a channel with nothing but arcs and Jacobs Ladders!
You should test wire nuts vs wagos
I did! See here ruclips.net/video/cMVnOZCGljc/видео.html