4,000 volt power supply (microwave transformers)

[MrSciencetificsasuke]

is the light bulb in series with the primary winding?

[ct92404]

@MrSciencetificsasuke

Exactly. All it's doing is adding resistance to the circuit, so that when an arc is drawn from the transformer, it doesn't cause a short circuit and an overload. But I've also found that a light bulb isn't the best way to limit current. You can use anything that runs on 120 volts AC. You just need something to act as a load.

[UTubeisSHIT523441]

Really great video. Good explanation. Thank you.

[TheError404]

@leaualorin 10000 volts - 1cm, so 4000 volts - 4mm

[thewinermaker]

use pwm

[67tr876]

I hope you know how fast that can kill you. Most microwave transformers put out over 1 amp ! I saw one that was 2000 volt at 3 amps ! You would be dead in a sec if you hit that !

[MrPeterBurban]

@67tr876 I don't think that you saw that correctly. If your numbers ware correct that would have been a 6,000 watt transformer. Volts x Amps = Watts That's like two electric dryers running at the same time. That's really high. Maybe it was 2000 volts @ (decimal).3 amps that's 600 watts much more realistic.

[67tr876]

@MrPeterBurban sorry but thats what the lable read

[TheTubejunky]

I think I will just play it safe with my 5V DC breadboard projects!

FOR NOW, The only high voltage I use is my 1,000,000V stun gun -=]

[Ace011mm]

Can you explane to me how to wiring one MOT? I not understand 3 wires on secondary.If I use light bulb,can I make ARC for long thyme?Do I need capacitor?

[DougieB1337]

Errrh, your transformers are connected in parallel? 

[ct92404]

@DougieB1337

No, they're connected in series. It works like a center-tapped transformer. The primary windings are in parallel, but the secondary windings are in series.

[DougieB1337]

@ct92404 Oh, I see, sorry 'bout that. Could the same be accomplished with a flyback transformer?

[ct92404]

@DougieB1337

Well, I don't have that much experience with solid state electronics (I work almost entirely with AC), but I would think that you could. From what I understand, the secondary winding in a flyback transformer is end-point grounded like a microwave transformer, so you should be able to connect two of them the same way. Just don't push the voltage too high so you don't burn it out.

[gabigowriel]

@ct92404 could a negative ion generator be made with 2 transformers like your setup? I know it would need a BIG diode( about 10 KV) positioned in the right way to get the negative source but the advantage would be that the voltage CAN'T DROP and the current IS HIGH so it will "rain all over the place" with INDUSTRIAL QUANTITIES OF NEGATIVE IONS! If it works I want 2 of those transformers please!

How much $ can they cost?!

Thanks in advance!

[ct92404]

@gabigowriel

They're high voltage transformers which you can find in any common microwave oven. They use a transformer to supply high voltage to the magnetron tube. Just buy a couple of old microwaves and take them apart. Connect the transformers in series like I have in the diagram to double the voltage output. Be careful though, there's a capacitor connected in the circuit and you need to discharge that first.

[BoogieWithStew]

That's a lot of voltage, Darwin is looking over your shoulder. Surely there is a safer hobby?

[gabigowriel]

@BoogieWithStew speeding on a supersport motorcycle , yeah! :-))) actualy I gave up that "sport"... better off with HIGH VOLTAGE, HIGH CURRENT AND "A BIT OF BRAINS"...

 CAN'T GO WRONG IN ANY WAY...

:-)

FOR @ct92404 : In ROMANIA I can't really find some damn used microwave ovens.., REALLY NOW : HOW MUCH DOES A HV MOT TRANSFORMER COSTS IN US?

Just as a "curiosity"!

LOVE YOUR VIDEOS!

[M1ST3RHYDE]

well done, Thumbs up

[Emman206]

were do you get a variable transformer ?

[kdkinen]

holy youre awesome man

[tylerjohnson98]

Thanks, iv been wanting to build a tesla coil out of these but I just bought a NST an hour ago but I would still want to use some MOT's to make a Jacobs ladder, could you show me how to wire them together?

[Serostern]

@tylerjohnson98 How many MOTs would you like to use?

PM me and we can talk a bit about it, I might have some schematics laying around.

[tylerjohnson98]

what is he using to control the voltage?

[ct92404]

@tylerjohnson98

I'm using a variable transformer to increase or decrease the voltage.

[Omnihilus]

@tylerjohnson98 the light bulb.

[voon100]

From my experience building any high volatge device contacts made directy onto the wood is very bad unless PVC insulator are used for the contact outputs.

I did this with a 5Kv neon power supply. I bolted two terminals directly onto the wood then connect the two HT wire onto the bolt, the arcing effect somehow didn''t work later I found out the wood conducted, thus shortening the circuit.

[Serostern]

@voon100 Depends on what wood you use.

I have a 10kv supply connected directly to wood, only about 2'' between the contact points.

It has ben no problem whatsoever.

...And that was BEFORE i treated my board with mineral oil.

[jerjanerayo]

diot i have 10000 volt 1 am power supply!

[RoboTekno]

cool, thanks for clearing some things up for me :P

[lexichronicle2]

Microwave transformers are about the most lethal piece of electronics most people can get their hands on, more so than 10,000V plus neon sign transformers, so be careful copying him nerds, or you'll accidentally electric chair yourself

[lapulapu12345]

BULB AS A DUMMY LOAD

[jk1567]

it dose not short transformer if it did the light will turn off

[ct92404]

@jk1567

The current is going THROUGH the light bulb. I was using the light bulb to limit current. Therefore, when the transformer is shorted it draws more current and the bulb becomes brighter.

[jk1567]

@ct92404 so when you short the bulb becomes brighter. you added something to it light will turn OFF!!!

[jk1567]

@ct92404 if you short transformer light will turn off i build microwaves :)

[ThinkLearnSolve]

@ct92404 it doesn't short the transformer

[ct92404]

@ThinkLearnSolve

Yes it does short out the transformer. When you draw an arc from a high voltage transformer, you short out the secondary winding. This cancels out most of the impedance (the inductive reactance), which causes a short circuit. That's why neon sign transformers have to be current limited, to prevent overloads. And that's why I use an external resistance with these transformers.

[urzaspath1234]

@ct92404 P=V*I so ur using 120v and u said about 2.5 amps so u have 300 watts but u also have a fan hooked up? so either ur drawing more current or ur lightbulb really isnt 300 watts?? just as a question :)

[Serostern]

@ThinkLearnSolve Yes it DOES.

[PlutonGB]

my mum woudnt let me to do that

[zhhyr]

Tried to post... got an error report !

[tHaH4x0r]

he i have a microwave transformer lying around, i might try this out.

[williamhad]

your shoe lase is untied... you dont want to trip dude

[stivep1]

r= r1+r2+r3+......... +RC of primary coil (serious circuit) .

So if RC is 10% of r

than only this 10% of voltage will produce inductance to secondary of the transformer.

If r has100V ( Voltage delivered )

If RC has10V( Voltage measured on the primary)

L= 1:2

Than secondary winding will give you 20V

[stivep1]

The secondary winding will reflect voltage inducted by factor of difference :

x of secondary divided by x of primary= L

X =number of windings. If L is 1 : 2 and 1(primary) has delivered (100V) :than 2(secondary) .will produce 200V.But only the voltage on primary winding will have an inductive force to affect secondary one. EXCLUDING ALL OF ADDITIONAL LOSSES ON ALL RESISTIVE COMPONENTS OF TOTAL PRIMARY CIRCUIT. Thank You.

[stivep1]

many years playing with electronics and still I think that this is great video

Now:

whenever you use anything in primary you are lowering voltage similar way to using Variac. the resistance of primary = resistance of all elements in primary.

The ohm law : current = voltage divided by resistance.

[fishcake1235]

Well made, well explained. Thank you :)

[williamblake69]

finaly .... someone explained it and demonstrated it in a way i could understand ..... THANK YOU ..... great video ..... just learning about transformers, very interesting devices

[havocdaemon]

Yup. I could zap myself a good one with one of those.

[Ultrabluu]

Exceptional intelligence, any theories for free electricity.

[therealromster]

I would be careful with that that 2,000 volts on each half is referenced to ground, so both leads are hot, much like the split 240volt American system 120 volts per a phase. With more than enough current to kill. Transformers can sustain short periods of over current, depending on room temperature and core and winding temperature and temperature rise time constant to not exceed the insulation melting point of the enameled copper wire. Very educational, be safe.

[ct92404]

It basically works like a mid-point grounded neon transformer.

[Tomatohead1122]

4,000 volts? isnt that illegal?

[ct92404]

No. How is it illegal?

[firedude201234]

where the hell did you get the idea its illegal?

[myfordescort]

@Tomatohead1122

If that was illegal then I'd be screwed with this 7200 step up I've got sitting in the back yard lol.

[serresjio]

lol its been made in 17-19 centuries and you still wondering with it. youre sick xD.

you can then add an very simple capacitor multiplier circuit to multiply these 4k to 16k or even 32k.

to pierce the surrounding air with the arc you need 16k on each 1cm of a gap; but this voltage may vary due to different ingredients of different airs and different pressure and temperature.

@Pyromadness: open a book and learn an Ohm's law!

[YAMAHIZZLETELEVIZZLE]

Excellent video!

[ArachnidFanatic]

2:45 lights in house are unhappy lol

[Bananadine]

It does look that way, but the later flickering of the image looks more like the camera's response to the great changes in the one light bulb's brightness... maybe the house lights aren't involved at all.

[johnnecron]

very educational and knowledgeble on your part

[stalkersas]

i use a 1+2kv heater as balast :) i have a military radar transformer, 2.5kv (2x 625 x2 windings) at 1.2 amp :) i have a vid with something similar, but much smaller. 2kv, o.6 A. oh, and with mots, if they are not crappy cheap ones, u can short it for up to 15 sec, with no danger, it will heat but, not enough to do ani damage at all

[Pyromadness]

hi everyone. i wana build a 2000 volt supply from an normal mot. uh i wana use lightbulbs to limit the current to around 10 amps but i thought the resistance from the bulbs reduces voltage not current? someone reply please lol

[ct92404]

For one thing, if you want to limit the current to 10 amps you will need to use something different than a light bulb. (Unless you can find a 1200 watt light bulb!) You can use anything to limit current...you just need some kind of load between the transformer and the power supply. Try a heater element, toaster, hair dryer, etc.

The filament resistance reduces current, not voltage.

[6418978876]

If you want to control the voltage could you use a wall dimmer switch connected to the 120v input?

[ct92404]

Not really. Dimmer switches don't work very well with transformers. They convert the AC sinewave into a chopped triangular waveform and when you turn the knob you're mostly just changing the pulse width. It's like changing the frequency. It's better to use a variac (variable transformer) to control the voltage.

[6418978876]

oh, good to know. Thank you.

[MacsCanfly]

yeah dude how could i control the volts that would be awesome i want to do it with a neon light transformer

[tribalmasters]

Imagine this fitted to the AMIR 9000 One Ton Microwaving Robot!!! I bet your professional microwave operator could think of great uses for it :)

[JohnnyDesaint]

i have a welder that does not throw enogh voltage too strike an arc any way that you know whats going on

[ct92404]

Arc welders supply very high current, but low voltage. Low voltage can't start an arc on its own. If you want to start an arc, you need high voltage...at least 2,000 volts. (Although I would recommend higher voltage for experiements, at least 6kv).

[johnb003]

Although for a welder you don't want an arc that crazy, especially with that much current. You only need like 50-60 volts, as once you just get a spark the high current will keep the arc alive. With 2-6kv you'll get more of a torch.

[highguard01]

nice one there good light show to improve for us please.

[rsaffe]

doesnt this give off harmful xrays??

[haxforcandy]

no, transformers give off EMP not Xray, the other part of the microwave gives off the waves you're thinking of.

[juniortore]

yes but little, very very little!

[jupy921]

Excellent job putting all of that together.

[Ravenpulse]

Great vid, lots of explanation, 5*s

[clusty1]

sure, use some screwed up language so 99% of people got no clue WTF you are talking about...

[ct92404]

If someone found this video, it's because they did a search for high voltage transformers and because they WANT to learn about the terminology. If they have "no clue WTF I'm talking about" then they have no business playing around with high voltage, period. These are not toys, and you damn well better know what you're doing before you mess with it.

[Eddlipton]

Sure do like this stuff !! Wish I'd known I would earlier in life then I would be able too FULLY understand the verbage and such. So what do you DO FOR YOUR LIVING anyhow? Seems we are all misguided into unsatisfiying carrers in this country. Think Russia and China may have had the anserw to that with dedicated education too natural ability

[negrutzyu]

I have only a microwave transformer for a 4000v power supply.I bought it two weeks ago with 13$ :)

[lara336]

If you are building a Tesla coil BE CAREFUL any contact with the transformer WILL be fatal.. your Tesla wont make sparks, it will make flaming arcs for fiery electricity.

[negrutzyu]

small amperage but high voltage....I didn't use that transformer...I sold it for 28$ making a profit of 15$

[n3rdbear]

@lara336 mmm toasty

[paraglidermx]

@lara336 Contact with any electricity can be fatal.

[thingyee1118]

cool i won't one ow well i got a microwave transformer!

[gmondrax]

How do i connect 3 microwave transformer and get 6000vac.. May you please send a diagram. I building a tesla coil but i can't find a good high voltage transformer... Please.. help

[HighVoltageScience]

use a neon sign transformer

[zezimashock]

why to the ac neutral?

why not to earth wire?

[STRIKER520]

Why not use a resistor not a bulb not the best idea.

[ct92404]

Actually, the best way seems to be inductance (with inductive reactance). I used a light bulb for a while because it was just easy and simple. But I made a ballast with a set of large chokes and that works a lot better. I have a video showing me using it with this power supply.

[rikardu90]

i think a resistor must heat too much... you'll waste energy by joule effect...

[tensago]

You are better off with a ballast that is less likely to fail ie not a bulb

[tensago]

are they not connected in parallel? by your diagram.

[ct92404]

As I explained in the other comment, the primary windings are connected in parallel, but the secondary windings are in series. The circuit is acting like a center-tapped transformer. Each transformer supplies 2kv by itself, but across BOTH transformers, you get a TOTAL of 4,000 volts.

[tensago]

ok makes sense. :-)

[kdkinen]

wow, smart

[Triple88a]

i would make a tesla coil :-P

[ct92404]

I did. I didn't use this to power a Tesla Coil, because 4kv is too low. But I have built several Tesla Coils :)

I have a bunch of videos of my 100kv Tesla Coil.

[Triple88a]

hehe beautiful, i will check them out now :)

[stripes5150]

I'm working on a real light sabre....I'll give you a hint...2 - 9 volt batteries...a mini inverter, a home made miniature step-up xfmr and a motorized-insulated-telescopic antenna...more or less a plasma sword

[stripes5150]

I sincerely appologize. I guess I should have looked at your diagram longer. I jumped the gun because I didn't see the jumper between the secondary windings of each xfmr. I thought the ground was tapped onto the cores...

I was wondering how you got it to work that way initally....You obviously know your stuff and I need to get glasses...lol

Keep up the cool stuff man!

[ct92404]

That's ok. Actually, the cores are grounded.  The cores of each transformer are linked together, and then connected to a common ground. What happens is that you end up with something like a center-tapped transformer. Each transformer only has to supply 2,000 volts (which is less stress for the insulation), but across BOTH secondary windings, you get a TOTAL of 4,000 volts.

[jstfrm09]

i have, like this flash bulb from a camera, is there anyway to light it up? can anyone give ways? like using 220-12 transformers, phot cap. etc..

[battlefeildrecruit]

its probably a xenon flash tube

it needs a lot of power about 4000 volts but im not sure how much exactly because all of them are different, but, it also needs a trigger coil, transformer and a capacitor, but i wouldnt try with out specialized help cause they can be lethal. even when hooked up properly.

[guimbadriver]

this video starts a idea in my head,uses a microwave transformer to feed a 300 watts FM trasnsmiter using a 4XC350 RF output tube..

[icuicu2006]

Microwave oven transformer are current limited by the shunt plates inside the transformer. Using the capacitors from inside the microwave (1 uF @ 2100 V) would help smooth the current out on the secondary side.

[ct92404]

You're thinking of a neon transformer. Neon transformers have shunts in the core which causes leakage inductance and is used to limit the current. (They have to be current limited because the gas tube in a neon sign shorts out the transformer.) But microwave transformers don't have shunts. They might have a limit to how much current they will draw because the core saturates, but by that point the windings can start to overheat. I've heard of the primary winding on a MOT catching fire.

[icuicu2006]

Nope - I'm thinking about a standard microwave oven transformer from 1985 onwards. In order for microwave oven units to legally sold in the US and Canada these transformers MUST be shunted for commercial use. Unshunted transformers draw unlimited current, and that simply isn't the case with MOTs. Your transformers will peak out at nearly 2 kVA each.

[ct92404]

I've taken apart dozens of microwave ovens and I probabably kept at least 6 transformers. I haven't seen core shunts on any of them. Granted, some of them could have been REALLY old (and possibly even older than 1985?) But most people will agree that you need to put a ballast in series with the primary winding of a MOT.

[icuicu2006]

Hey, I'm not knockin' your video. Its great to see people using high voltage to generate arc and sparks :) Yes, you are right - when you arc an MOT it can pull up to 1.8 -2 X the normal power rating. This is quite normal. Have a look between the primary and secondary - their you should find a block of shunts wrapped in insulating paper - these will be on either side of the spacing between the cores. Trust me - they are present.

[ct92404]

...Also, look at how many videos there are on YouTube of people drawing arcs from a MOT (for a Jacob's Ladder, etc) and it trips a 15 amp circuit breaker. One of my friend's MOT kept doing that until he started using a ballast. I prefer using neon transformers for high voltage experiments anyway. I only made this video to show how you could make a HV power supply with two MOTs connected in series, for about 4kv total.

[angrysausage123]

Has your safety switch ever turned off from overloading?

[ct92404]

You mean a circuit breaker switch? No, and that's why I use a ballast with these transformers, to prevent overloads. So they won't trip a circuit breaker. Although I HAVE tripped circuit breakers with OTHER things!

[angrysausage123]

Kewel!

[skuitarman]

ok I used a really old iron-hydrogen resistor as a ballast and it works great

[skuitarman]

could I use some kind of resistor as a ballast

[ct92404]

Sure. Actually, you can use pretty much anything as a ballast, just as long as you have some kind of load in series with the transformer. Some things work better than others. You could even use a toaster or a heater element as a ballast. What happens is that if you short out the transformer, the transformer's impedance almost disappears so it becomes a short circuit. Then pretty much the only resistance in the circuit is your ballast. So you need a ballast to prevent an overload.

[skuitarman]

and what light bulb would u use for one 1100 watt transformer.

[ct92404]

well, I don't know of any 1100 watt light bulb, except maybe hallogen bulbs and that would get extremely hot. But you could connect several light bulbs in parallel. Or better yet, just find something else to use as a ballast. Like maybe a heater element or a toaster. You could also use inductance as a ballst. I have a video showing my inductive ballast. Look at my page.

[skuitarman]

does the hot 120 volt wire hook to the light bulb and then too the transformer?

[ct92404]

You would connect the light bulb in series with the transformer. So yeah, one wire from the light bulb would connect to the 120 VAC hot line, and the other wire on the light bulb would connect to the transformer.

[Diametrac]

Thank you for posting. Very interesting.

Be a teacher - be a hero.

[ErikJoeNoise02]

hello there. can i ask you something? how can i produce a eletromagnetic pulse ?

[CJackSparrow79]

i'd use bigger cables

[VideyoJunkei]

:16 might be interesting to wire 1 primary in reverse, getting +- voltage at any moment.

[ct92404]

If you try to connect the primary windings in reverse, they will be out of phase and most likely you will just end up cutting the voltage in half (if the transformers will even work at all). There's really no such thing as '+' and '-' with AC, since the polarity is constantly changing at 60hz. But if you connect transformers together, you have to be sure they're in phase - that the AC sinewave is rising on both at the same time.

[avinetine]

I have two mid point grounded neon sign transformers, both identical, with a secondary voltage rating of 4,000 and 30 mA. Could these be but in series to make an 8,000 volt power supply? If so, what would the circuit diagram look like? I hope to use it to power a Tesla coil. I've been using your videos as guides and they are very good, thanks for the help.

[ct92404]

LOL...nope, I'm not! But thanks! I just do this as a hobby, but I have been experimenting with high voltage for about 10 or 11 years now. I work with AC almost exclusively.

[TCDIL95]

this is a very good and detailed video on your set-up! but i was just wondering what the two red terminals on both sides of the center tap were?

[ct92404]

That connects to the filament windings on the microwave transformers. Normally, the filament winding is used to supply low voltage for the filament on the magnetron. I didn't use them, but it was easier just to leave the windings on the transformers than to take them off. So I left them on and made extra terminals just in case I found some use for it later on.

[TCDIL95]

yea that makes sence.

i would never be bothered taking the filament windings off my microwave transformer.too much work. if they are in the way you could always just stip them?

[calfellows59]

Free Electricity 90v, 200ma, 13watts

/watch?v=Kdup42Epq0o

Sound Waves Create Electricity 56 Volts

/watch?v=aFSwQouGPcA

One will power the other

[icuicu2006]

I'd ditch the lightbulb as a ballast all together and just get 2 MO caps and place them in series with each HV terminal. I'd expect that you'd run 2200 - 3000 watts output so running the transformers off 240V would work well. This is quite easily accomplished with two MOTs.

[ct92404]

I've tried using capacitive reactance to limit current before, and that doesn't work too great. The capacitor got really hot and the arc turned into a loud popping discharge instead of the smooth arc you normally get with AC, so to me that was a sign that I was getting some high frequency ringing that's not good for the transformer. Also, I prefer using the ballast on the primary side.

[Radant]

awesome stuff, im going to make a MOT bank, hopefully i wont electricute myself

[ct92404]

Cool! Just use common sense and you'll be fine. I've been playing with high voltage for over 10 years and I'm still here :)

Good luck.

[4Teddybears]

You should connect one transformers' output to the others' input. Usually with one transformer You're puting in 120Vac and getting out 2000Vac. Thats multiplying the input voltage by 16.7. So what happens when you stick 2000 volts into the primary coil of your other transformer? you get over 33,000 volts! sure the amperage decreases considerably.

[ct92404]

Transformers don't work that way. That wouldn't work, because then you would be trying to drive the second transformer's primary winding with the current from the first transformer's secondary winding. You would overload the first transformer. Also, there is no way in the world these transformers could handle 33,000 volts. The insulation is way too thin. You would get arcing between the windings and flashover to the core.

[ct92404]

...actually, probably not even that would happen. All that would happen is that you'd saturate the core of the second transformer and they would both just overheat. And if you didn't use a ballast to limit the current, it would just trip a circuit breaker, because the second transformer would try to draw a HUGE amount of current if you dumped 2,000 volts into the primary winding. Think about Ohm's Law. The winding has maybe 10 ohms of resistance. 2,000 volts divided by 10 ohms = 200 amps!

[cdvcarthasis]

dude are u like an electrical engineer? that's pretty cool

[Lexy015]

does your insruance compnay know you do this in your house?

[TCDIL95]

so thats why my mot has such small arcs.

[hvhaxor]

you dont need to ballast only 2 mots it wil only draw around 11A and you can get arcs 3" wide with it

[codemsan]

uhhhh, a single MOT will do around 18A, both of mine un-ballested will do about 30A!!!

[hvhaxor]

i have ran 2 mots unballasted with secoundarys shorted on a 15A braker

[codemsan]

they must have been very small...

[hvhaxor]

1 1000W and 1 900W

i run my 4x mot bank off of a 2000W ballast with a 15A braker

[ct92404]

I still wouldn't recommend running a MOT without current limiting. I have heard of the primary windings catching fire. If you look at codemsan's videos, you can see how often the circuit breaker trips in one of his videos. I saw another video where someone connected a MOT directly to the service lines in their panel, from the pole transformer, to bypass the circuit breaker switches because they kept tripping...NOT SMART! That will overheat the bus bars and could cause a fire.

[hvhaxor]

my friend runs 4 1200W mots unballasted on a 60A braker we keep out mots in mineral oil to prevent internal arcing but it also keeps them cool so i suggest that

[icuicu2006]

MOTs are current limited - just not well. I have a MOT stack at home that uses no external ballasting. The unit draws no more than 32.5A on 240V service. If this were ballasted I would have already tripped the breaker by now.

[TheBypasser]

Can't see a thing..

Is it only me, or there's no cooling fan in this device? Carefull then, MOTs in alike conditions heat up like hell ;)

[Icarusdecending82]

Future physics major!

[mozart553]

Careful shipmate! Dont blow urself up lol. Your smarter than the average bear boo boo.

[FinnishBerserker]

Theres no need for light bulb or current liminting coil if you have a tranformor that gives you under 4 amps (at least 0.20 amps) it's different in eurepe cos we have 230V wall outlet , but that doesn't really matter when u ballast the current. So the best way to ballast the current is to use for exmpl. a fluoricent lamp transformer before the two MOT's to get 0.53 amps(That's what my ballast gives). Light bulbs are inconvenient cos' those really just suck your money from your electric bill :D

[Mikeyboy30]

Yeah was wondering when he said 120v supply lol

[nothingisrealiamthe]

very imformative

[bobdavis321]

I have wired 4 MOT's together to get 8KV. But there were problems of arcing to the frames on the outer 2 transformers.

[ct92404]

Yeah, 8kv is really pushing things. These transformers have thin insulation and they just weren't meant for voltage that high. I would say that the max is 3 transformers in series, any more than that and you have to put them in oil for insulation. The way I had it here, there's 4kv total, but with a center tap each transformer only has to withstand 2kv.

[stephenthepilot]

it's possible to connect 6 mots in series without putting them in oil

( thats 12kv )

u have to ground the 2 cores in the middle mots and then unsolder the secondary winding from the core of the outer two mots,

this acts as a mid-point grounded transformer,

i have a 4 mot power supply without oil, i soon hope to find another 2 mots,

i have a video of my 4 mot jacobs ladder

[FBRK8R]

Thanks for this Chris, just what I need to get my coil working

[ct92404]

Great! I'm glad the video helped. The only problem is that 4kv is probably still too low for a Tesla Coil. You might be able to make it work, but you're going to have trouble getting your spark gap to fire smoothly. Also, you should probably use something different to limit the current. A light bulb works, but it does seem to drop the voltage a little. You want all the voltage you can get. Try an inductive ballast like a motor or a big choke.

[codemsan]

i love this power supply!