20KV High Voltage Transformer - Jaycobs Ladder demo

[TheCessnaDriver]

bitchin!!!!  :)

[lexichronicle2]

Impressive dedication thar, building your own!

[hvpower]

Really nice transformer! Congratulations for this awesome work. Regards hvpower

[joeylawn36111]

Very nice. But have ventilaton where you run the Jacob's Ladder - it makes toxic Nitrogen Oxides.

[normellow]

I'll send you transformers free of charge

[TheError404]

1000$??? I could make one for 100$ or even less. Buy a big core from scrapyard, wind your own primary and secondary

[Zorrobeat]

Sounds mighty!

[death7metal7girl7]

I love this!

[lokeycmos]

good job! wish i had 1000 dollars to build one!

[2012thedevil]

VERY FUCKING NICE!!!!!! COULD YOU SOMETIME SHOW THE WHOLE TRANSFORMER AND EXPLAIN YOUR CONNECTIONS?! I'VE BUILT A 3kv at100mA BUT NOTHING LIKE THIS!!!

[s28400]

Holy Shit. $1,000??? You should of just picked up a few microwaves, those have equivalent transformes in them and are dirt cheap compared to this.

[bjtaudio]

@s28400 Yea I have a few Microwave oven transformers too, however they only have an output of approximately 2000Vac My transformer is 10 times that voltage! and I can go even higher because I have a massive winding window, and HEAPS of clearances that is critical. Putting microwave Oven Transformers in series to build up the voltage is unsafe, as the insulation and clearances cannot go much past 4KV. Also dependent by the size of my winding wire, I can get a few hundred KVA !!!

[bjtaudio]

@s28400 Note that the arc is small and is limited to the amount of power I'm feeding the transformer being about 8kva. I could run it up to 100KVA and get huge violent arcs if I had the power available to the property.

[stephenvdb]

i bet you hair stood on end when you touched the door handle afterwards!

[YummyMercury]

@stephenvdb So tempting to troll... :3

[RuheSanftGmbh]

What did you use for the insulation?

What wire did you use for the primary and what for the secondary windings(in milimeters)

[bjtaudio]

@RuheSanftGmbh it layer wound, using a few layers of (DMD) Dacron/ Mylar/ Dacron F class 155Degree dry type Insulation between winding layers. The 240v primary uses standard Class H 180 Degree 3mm enameled copper wire 165 turns of (7.07mm2) and secondary uses 10,000 Turns of 0.5mm enameled copper wire (0.197mm2). Ratio 1:60 approx, Core leg is 67cm2 area of Lycore 150 laminations flux = 1Tesla 1.45Volts/per turn, In the video it running at 2Volts/turn to get 20KV using other leg.

[bjtaudio]

@RuheSanftGmbh he core is made of 80mm wide 0.5mm laminated sheets cut into 3 different length bars 80 x 270 x 0.5mm and 430 x 80 x 0.5mm and 110 x 80 x 0.5mm. the core is a assembled into a large rectangle where the different length bars are arranged to overlap and sandwich together, ending up with a 270 x 110mm over-sized winding window! stack height is about 86mm. core is pre-wound, varnished, and sealed, then core is built up around the bobbin/windings, and all clamped together.

[ubuntupokemoninc]

I've have been winding my own transformer, i made the core out of steel bar welded, will that work?

[bjtaudio]

@ubuntupokemoninc Probably not, as the eddy current will be massive, the windings are likely overheat, terrible efficiency. The core must be made of flat steel sheet segments about 0.5mm thick, and all laminated sheets must have a fine insulating coating. Do a search on goggle and see what a EI laminated core looks like. Mine is made of sheet bars arranged into a rectangle, the sheets a layered on top of each other, all the same orientation, and clamped together , do not weld the core!

[bjtaudio]

@bjtaudio The welding is a short, and will reduce efficiency, as eddy currents will flow in the core. The clamping should also be insulated from the core. The bets way to make the transformer, is to pre-wind the windings on a bobbin, you will have to make, then you build up the core layer by layer, passing through the center of the bobbin. No gaps! the layers must be very neat and tight, and perfectly square, or efficiency will be poor, and magnetizing current will be too high, clamp tight!

[bjtaudio]

@bjtaudio If you're in Australia the cheap option is to contact Sankey and get them to cut you up some Lycore 150 bar, you will first thou have to decide the sizes, also the layers of the core should over lap each other, they don't just butt together! or a more expensive option is to contact, OBA Insulators, and purchase a C core, or AEM cores, they sell the cores, and bobbins...but it's expensive!

[ubuntupokemoninc]

@bjtaudio, Ok thanks, another question, i have a huge isolation transformer, with a core, the core is peeling apart, do i just peel it apart, scrap the old winding out, and put my new winding, then on it varnishing the core back together around my winding and baking it at say 175 degrees F, if I'm gonna run 25kva, (240vac) what gauge wire should i use for the primary(240vac) and secondary (7,200volts). 

[bjtaudio]

@ubuntupokemoninc It hard to say without seeing the transformer, however when you peel the laminations apart, avoid kinking and dinting them, as when you try to reassemble the core, gaps between the laminations will reduce the efficiency, where the magnetizing current will be considerably higher, also more unwanted heat will be generated. Winding wire size needs to be calculated, also need to know the size of the core's window. go to this site:- ludens.cl/Electron/trafos/traf­os.html

[08Kutt]

wow likes a giant FLYBACK!!!

[BlanchProductions]

Is there a name for doing that, making the electricity jump over like that?

[bjtaudio]

@BlanchProductions Yep the effect is called the Jaycobs Ladder hence the title. The electricity is only able to breakdown the insulating properties of air and jump across the 20mm gap due to high voltages. The higher the voltage the further it can jump through air, and the more pleasing the effect. Also as the current increases you can drag out the arc over longer distances. The arc of "flash over" is almost a short circuit, so current limiting is needed.

[bjtaudio]

@bjtaudio I should mention that u need to take extra caution near medium and high voltages that utube members have used to make their ladders. Mine is a deadly 400mA but some members have used several amps, where even brief contact with the arc, or conductors can be fatal. I never go anywhere near the wires, horn, or transformer when energized, I do not use wood and sticks like some members have as a hot rod.

[bjtaudio]

@HazzWold1993 Finally if you want to make up a transformer, while it is simple there is a lot more to know. I can help, my email is bjtaudio@ gmail.com

[bjtaudio]

@HazzWold1993 Note they have a range of different sizes Lycore 150 coils ranging from around 50mm and upto 150mm wide. Best to ask what sizes they have in stock, and choose from that, or they will charge you more. If you want holes punched so you run bolts through the corners of the core it will cost more! I just clamped mine no hole to save cash, but this in not ideal.

[bjtaudio]

@HazzWold1993 I ordered the laminations cut to my specifications from Sankey Australia, and then assembled the core. It's made up of straight bar laminations.

[bjtaudio]

The core is made up of Lycore 150 0.5mm bar 80mm wide. In the factory the laminated 0.5mm thick coil comes on huge rolls and they roll off and cut the coil into segments or bars to the length your require. I needed 3 different lengths to make up the 60kg square "O" shaped core. It cost $365 inc GST and delivery.

[RODALCO2007]

Awesome job and very professionally done. Thanks for showing.

I may have a go at that as I have an of old 400 / 11000 Volts POCO transformers in my garage.

[bjtaudio]

Anyone that's interested High voltage projects, where microwave oven MOT, and Neon Sign Transformers NST, are not powerful enough, with time and patience you can wind your own. The cool thing about mine its it has an extra large winding window, 270 x 110, and one leg of the core is free for you to wind any winding you want, you can go from 12V to 20KV if you want, you can do anything and are not bound to what the transformer was originally intended for. If it fails you can fix it.

[drdreads1]

awesome dude! where did you source the core? iv been wanting to do a project like this for use on a tesla coil.

[bjtaudio]

@drdreads1

I Assembled the core from Lycore 150 laminations. They consist of 80mm wide 0.5 thick bar cut to 270, 110 and 470mm lengths which are then stacked and interleaved forming the core. Sankey Australia is the source and my contact is in Sydney a Andrew Hill. The turn around time was 6 weeks, which is slow but they are the cheapest I could find, and they make the core to the size you want. Bevan

[Twizt3dArc]

WOW!!!! where did you learn how to make such an awesome transformer?

[bjtaudio]

@Twizt3dArc - It's actually rather simple to make them, however I researched how to make them using Google, I found a free transformer program which calculated flux, volts per turn etc, and then experimented to verify that the results I was getting matched the calculations of my free program. High voltage is more of a hassle thou because you need to take more care with your clearances, and dielectric strength of insulation, or you will get a arc flash-over on the winding of your transformer.

[Twizt3dArc]

WOW!!!! where did you learn how to make such an awesome transformer?

[Kylecchh]

That's awesome! I'd love to see that transformer in resonance. ;P How many turns on the primary winding do you have?

[bjtaudio]

@Kylecchh It has 165 turns of 3mm dia enameled copper wire (7.07mm2) for the 240V primary. The High Voltage secondary is 10,000 turns of 0.5mm dia enameled copper wire, which is 0.198mm2. When operated from 240V mains it gives about 14,400 Volts, but with high fault current! For 20KV I roughly wound a second primary 50V winding using 25 Turns of pvc insulated wire on the other LEG of the core, driving the core harder at 2Volts /per turn, the current is limited by the undersized 50V cable.

[bjtaudio]

@Kylecchh IMPORTANT:- I need to mention I was driving the HV transformer with the 50V winding at 2V/turn Hense:- 2 x 10,000 =20KV. The source of the 50 Volts was yet another transformer I made myself which was 240 to 52Volts and 7.5KVA huge! it gives hundreds of amps easy...My current was limited to arround 170 Amps at 50V because I was using 6mm2 pvc Wire, far too thin, but was good enough for a short demo run for the video. Another current limiting factor was the long flux path in the core.