MINI TESLA COIL

this is a very cheap mini tesla coil made of stuff i had lying around.
how it works: "Electricity flows into C1 until a high voltage is seen across G1. When this voltage is high enough, a spark jumps across the gap and allows C1 to discharge into L1 and L2. The voltage "bounces" back and forth at an extremely high rate. When the rate of discharge between C1 and L1 matches the rate of C1 and L2, the two circuits are said to be "in resonance" and the voltage goes up through the roof."

DANGER HIGH VOLTAGE: although the amps are relatively "low" this can still be dangerous. always turn it off before making adjustments unless you are experienced. I TAKE NO RESPONSIBILITY IF YOU GET HURT!

Step 1: You will need...

parts:
a 9.5in x .9in (od) PVC pipe 
15 high voltage capacitors 
matching round head bolts
wood
a bottle
2 pens
electrical tape
speaker wire
about 300ft of 32 awg mag wire
18 awg solid core hook up wire

tools:
saw
knife
drill
hot glue gun
different drill bits 

power source:
flyback driver or
NST 
(1-10kv)
 

Comments

[parker davis]

what was the total cost for building this
considering doing this with my science club
but we have VERY limited funds

[Jimmy Proton]

The only thing I payed for was the magnet wire, you can get it somewhat cheap

[kingpinzion]

how did you remove the diode from the dc flyback transformer...plz explain
ty in advance

[wdrake1]

Is this the proper wire to use for this step?
http://www.ebay.com/itm/2Conductor-18AWG-Solid-Bard-Copper-500FT-UL-Listed-Wire-/190556711734?pt=LH_DefaultDomain_0&hash=item2c5e10ab36

[wdrake1]

Hi, I am looking into building this with my science club. I just want to know- In the parts list it says "300ft of 32 awg mag wire, but in step 2, it mentions 28 awg wire. is there a difference? thanks

[Jimmy Proton]

Oh sorry, didn't notice that, 32 awg is thinner, use 28.

[ved choupane]

how much does it cause? Are 15 year boys enough?

[Electrodude]

can you use electrolytic capacitors?

[Jimmy Proton]

No. electrolytic caps dont have very high voltage ratings so you would need a lot, plus this is AC, electrolytes are DC

[Bumba Lodh]

Hi,I built a TESLA COIL with 5kv 30ma nst.Primary coil made with 4mm
copper tube with 10 turns secondary made with 2inch PVC pipe.Winding
height 10.2inch(0.315mm enameled copper wire used) also made Capacitor
bank with 2kv 0.15uF polyester film capacitor.But the problem is my
Capacitor burnt several times but the coil works with LEYDEN JAR
capacitor.Why the capacitor burning??????


Please Help Me!!!!!!!!!!!!!!!

[Jimmy Proton]

well if you're using a 5kv nst and your capacitors are only 2kv, the problem is kind of obvious. (assuming you're using 50Hz) the exact resonate frequency of your transformer would be 0.019uF, you can achieve that by just putting 8 caps in series, this will also increase your voltage rating to 10kV, so they shouldn't burn out unless you're using bad caps.

[Bumba Lodh]

i tried to put 5 capacitor in series to increase the voltage rating to 10KV and also tried put 8 in series but every time i get the same result should i use polypropylene film capacitor?

[Jimmy Proton]

Yeah you should try a different kind of capacitor, im not sure what kind but polypropylene film caps should work fine, just dont get cheap ones!

[aweis]

so how about 70 volts alternating current, a kila volt that is one thousand volts right?

[Jimmy Proton]

70V is way to low, for this one you need at least 1kV, the supply I was using was about 2kV.

[zanki_kitsune]

yes but 1kv is after the transformer, that increases the voltage, when really your power source was likely the 110-120 volts of a house outlet unless your the European 220. so instead of 120 how about 70v before the transformer is what i was asking. wich i know is entirely possible now. just not as powerful.

[lug big lug]

well it depends on your transformers output.... thats all that matters

[sudhanshu529]

hii !!! i have secondary on a 2.5 inch PVC and my toroid is made of aluminum duct . now i want to know whether there is any electrical connection between these 2 . how should i mount the toroid on the secondary ??

[Jimmy Proton]

You connect the wire on the end of the secondary to the toroid and mount it on top of the pipe, make sure there is no metal in the pipe though.

[sudhanshu529]

so i have to connect one end of the secondary to the toroid ? what about the other end ??

[Jimmy Proton]

The other end goes to ground, but I didn't do anything with it on this one, just left it there.

[aweis]

i plan on making a smaller one than this, besides people can get several hundred thousand from standard wall outlet, 120 volts, and i intend to have a high voltage transformer, which you seem to be not using, i will not use a flyback transformer, because f expense, are not those for makeing direct curent into alternating current? i plan on making many of my own capaciters, and where can anyone get a 1kv power supply without breaking the bank, all i need is a tesla coil to produce tiny sparks, the generator alone can produce a quarter of a centimerter sparks already, so a smal tesla coil made well enough could probably get me something visable, it is my first tesl coil, and all i need is it to be at least 6 inches tall, and produce some sort of electrical discharge. do expect everyone to make the exact same one as you?

[Jimmy Proton]

Still, even 100V is to low for that, 500V is more of what you need, maybe more. You can use an electronic lamp ballast probably, the one I have is 580V and I use it to power my 100kV flyback. I have herd that you will probably get AC output from a DC input from a flyback which is the only explanation why I can use a flyback to power this. By this way, this is poorly made Tesla Coil and creates very small
sparks.

[thunder strike]

and as well i intend to make mine better improve it ad a toroid, to increase spark production experiment with making bigger sparks, and also something such as a neon sign transformer make it quite a bit more powerful from standard house electricity, with something like that does it have to be standard socket power to power the neon sign transformer. something funny just happened that i had to put in here, i misspelled something and when i used spellcheck one of the suggestions was "typo"

[aweis]

wait electonic lamp ballast is that used in some way to produce enough electricity, to power the capaciters, wich actually where the power is converted into hiugh voltages from, so i would technically be able to make a small maybe 6 inch tesla coil work, it is just the wind up for the electrical discharge may take a while the first time and have more space inbetween,

[Raymond Tahjono]

and bytheway what does a flyback driver look like? any websites to help me see images&examples would be greatly appreciated !

[lug big lug]

search google images for flyback drivers

[Raymond Tahjono]

For the 15 high voltage capacitors, I will need 15 of them? and what does it look like?

[R.A.T.M]

you do realize that the wire wrapping is wrong its not the wright amount its 2 much more your power source the point of the coils it to increase the voltage and get a ark that dosent need a direct ground yo put arks

[sguy1]

i am working on teslacoil. and i don't get one thing! which of the wire positive or negative from capacitors joins the spark gap? is it negative? if so what to do with the positive wire from capacitor?
what about grounding ? is it primary coil or secondary coil or capacitor to be grounded?
and what are the things that we people be careful of while making this stuff.

[Jimmy Proton]

There is no polarity is this, it is AC, the bottom of the secondary is grounded and just dont touch anything and you'll be fine, although I would say that the streamers are safe to touch for something as small as this.

[sguy1]

oh so you mean that we can join any of two wires from capacitor!!

[Jimmy Proton]

Yeah.

[sguy1]

what if we don't include capacitor? will it still work?

[Jimmy Proton]

no.

[sguy1]

thanx for the replying soon. keep making these cools stuffs.

[aweis]

by a 1 killavolt supply since i doubt anyone will have a generator of that capability, you mean such as a, do not remember what it is called, but it mutiplies the voltage. such as a neon sigh transformer. or another supply, i might just make a small Jacobs ladder.

[Jimmy Proton]

Cockcroft–Walton voltage multiplier?

[robcwise]

I've been planning on building one, but I don't understand why you need a spark gap. Could you explain to me what its for?

[Jimmy Proton]

You could compare it to the heart in the brain, the brain cant control the heart without blood and the heart can't supply blood without the brain. with the heart being the spark gap and the brain being the capacitors: the capacitors charge up via the transformer, when they are charged the spark gap fires and the capacitors release their energy into the primary. without the spark gap you would have continuous input into the primary and without the capacitors all the power would just go straight through the spark gap.

[sudhanshu529]

hii .... actually this is my first attempt to tesla coil ... i m doing it for my college project ... i use a secondary coil 63mm in dia , with wire .3mm thick and 1000 turns... my primary is made of 10 SWG wire with 6 turns with first dia being 160 mm and consequent turns 5mm apart .. i had ordered a transformer 220/4000V and 35mA ... i dont noe whether it is current limiting or not ... i made toroid using a 4inches aluminium duct .. 22 inches in circumference ... now a few questions :-
1) can i use a series of 400V capacitance for primary ?
2) what should be the value and current rating of my bleeder resistance ( connected accross capacitance)
3) how do i limit the current ; provided i dont noe whether my transformer can limit the current or not ... ?? if using a choke what would be a good value of the choke and its rating ??
4) can i wind primary on a wooden structure or do i need acrylic sheet or Bakelite ???
5) how do i tune my tesla coil ... i have no access to occilioscope :( :(

thanx alot BTW for sharing your experience !!!

[Jimmy Proton]

1-The caps have to be about 2 or 3 times the input voltage, you can wire them in series to increase the voltage and just to throw it out your capacitance should be around 20-25nF.
2-10M ohm resistor is what most use.
3-sorry I do not know the answer to that.
4-anything non-conductive should work just fine.
5-to tune your Tesla Coil you can adjust where the connection is on the primary, you can change the capacitance of the capacitor bank, and you can adjust the width of the spark gap, you could also experiment with different sized toroids.
Do you have any pictures?

[sudhanshu529]

thanx alot ..... yea i have pics and have made video of the construction .

[thunder strike]

i do like how you answer the questions that are posted, while i am still waiting for other questions to be answered on other ones, good job.
P.S. i am the same person as AWeis but i wanted an actual account for me and my friend to post, on what we make.

[Jimmy Proton]

Thanks!

[aweis]

i am a scince nerd, so i wish to know how this revent a lethal radio onterference with other electronics?

[Jimmy Proton]

They reduce the electric field.

[aweis]

that is obvious i want some knowledge on how this is done. i am the person who wants to know how everything works, before i make it.

[Jimmy Proton]

Well I am not entirely sure but from what I can tell it induces current in conductive things around it, which we all know can destroy electronic devices.

[aweis]

all i know i that because electricity wants to go in a straightis line when it moves in a circle a tight circle, or a right anngle it will send a magnetic charge off and reenter the rf choke at the same or similar angle, internesting topic.

[Jimmy Proton]

Even a straight wire gives off a magnetic field but a coil is much better for stronger effects and a coil around iron makes it even stronger.

[stamna2]

Can i built it from 30 awg magnetic wire ? The rf chokes are built by magnetic wire too?(can i built the from the same wire?)

[Jimmy Proton]

Yes, yes, and yes

[stamna2]

Should i get a metalic cage around from this to be more safer???
Thanks a lot

[Jimmy Proton]

Nah, the sparks are very small but whenever i rebuild it, it will have much longer sparks but still not that powerful.

[stamna2]

What are L1 and L2 and g1? Are they the RF chokes (l1, l2)?

[Jimmy Proton]

L1 and L2 are RF chokes and G1 is the spark gap.

[stamna2]

Thnx

[sudhanshu529]

hello . for my collg project i am building a tesla coil .. i have a doubt though .... do we use ac supply or dc ???

[Jimmy Proton]

There are DC Tesla Coils but This one only works for AC. *300th comment*

[sudhanshu529]

thanx for replying jimmy ... i would like to add 1 more question .. when the capacitor charges to let say a value "v" volts the spark gap closes ... now it hardly matters if we use dc or ac because in either case it only reaches "v" ... so the whole 2 pi cycle will not be completed .... so y use ac ??

thanx in advance

[Jimmy Proton]

It has something to do with charging the capacitors, they never charge and the spark gap don't fire when I used DC but I'm not saying to use electrolytic caps because they will explode.

[N3v3rm0r3]

28 awg? How much is this in milimeters(mm)?

[Jimmy Proton]

0.32mm

[luisantonio]

Hi Jimmy, I'm a freshman here, and I thank you for your help. I'll try to build a Tesla coil using a 2100 Volt capacitor of 1uF, could it work?. I'll use it cuz i already bought it. Any thing i write you.

[Jimmy Proton]

yes, that will work, for tesla coils you wat the lowest farads and highest voltage possable, thanks for your comment.

[Xellers]

Nope, that isn't quite true. Resonance is what matters, not capacitance. Also, you want to make sure that your capacitor is matched to your transformer (if it's an AC Tesla Coil) to make sure that the capacitor charges completely during each half cycle, only discharges once, and doesn't being to charge again. Also, you should use no fewer than 6kV if you're just getting started, setting up a good spark gap for a 2kV transformer can get very tricky. Although you can brute force everything by throwing together a bunch of parts that are not compatible and settle for modest results, you could instead do some research, calculate the optimal values, and try to work to reach them with what you have. When I started my first Tesla Coil a few years ago, it used a flyback transformer from a TV set and an adjustable 555 timer driver (almost identical to the power supply used in this instructable) and threw some modest 2 - 3 cm long sparks. However, after some months of tinkering around, I was able to rebuild the coil around the same power supply and achieve 5 - 6 inch long sparks, an increase in spark length of over 500% !

[Jimmy Proton]

When I made this I really didn't know all that much about Tesla coils, i just wanted to make one and make an instructable on it, as you can see on the last step I am building a much , much bigger coil but this time I did lots and lots of research on it, the only part I need now is an NST. Iv'e already made the instructable, I just need lots of pictures to ensure it will get on the front screen. I have one question though, how do you determine how many caps to put in series and in parallel, I know it has something to do with the output power of the PSU, I really want a 15kV 60mA NST but I'll probably have to go with something else, anyway the caps im using are 0.001uF @ 10kV, wouldn't that be two in series to get 20kV but how many in parallel, I will aether be using 30 or 60mA and Im probably going to hook up a MOT to it so what about that?

[Jimmy Proton]

Actually i have rebuilt this and i got twice the output power.

[Pale_Flyer]

so you have made an induction charger with range. COOL!

[Jimmy Proton]

yeah i guess so but this is very low power!

[physicsnerd]

how much power does this power source have to be? will a class 2 transformer that outputs AC 9V 300MA work?

[Jimmy Proton]

No, it must be at least 2-15kv.

[spencer210683]

i have one of these at home see pic could i use this as a powe supply thanks james

[Jimmy Proton]

no its to powerful, something in between 6000-10000V would probably be best for this although you may be able to go 2 15000V

[lightning r fun]

instead of a flyback or NST, would i be able to use a marx generator power supply to run this?
http://www.instructables.com/id/High-Voltage-Power-Supply-For-Marx-Generator/

[Jimmy Proton]

i dont see why not, all you really need is a continuous AC power supply

[lightning r fun]

and i dont have a working nst

[lightning r fun]

I am trying to make a handheld (sort of) tesla coil, and i am trying to run it off of a drill battery(18v 1.5A), so I want to get some sort of high voltage supply to run off of the battery which is dc not ac.

is there any sort of voltage multiplier that runs off of dc instead of ac?

would a MOT work with a flyback driver?

[Ceiling cat]

Good news! Someone has done that! And they posted an instructable! Hope this helps.

[lightning r fun]

which means that i need a real high voltage power supply

[Ceiling cat]

Not at all! You just need an ignition coil; which can be found at an auto parts store or salvaged from an old or dead car, and a few other parts which can be bought online or salvaged from old or dead electronics. No high voltage power supply is needed! I think the ignition coil just takes the high amperage/low voltage power from the drill battery and converts it into low amperage/high voltage power. This happens after it's gone through the filters to remove radio interference and clean-up the signal, and through the relay which replaces the spark gap of a normal Tesla coil.

[lightning r fun]

?

[lightning r fun]

does an ignition coil emit AC or DC HV

[Ceiling cat]

I think they are made for only DC.

Here are some links to help you out. It sounds like there's a lot you still have a lot to learn (no offense).

http://www.instructables.com/id/High-Voltage-1/

http://www.instructables.com/id/Quick-and-Dirty-Hand-Held-quotTesla-Coilquot/

http://www.instructables.com/id/Tesla-Coil-Projects/

http://www.instructables.com/id/Tesla-Coils-for-Dummies/

http://www.instructables.com/id/How-to-build-a-Tesla-Coil/

Or you could just get one of these:
http://www.teachersource.com/ElectricityAndMagnetism/TeslaCoils/OudinCoil_InchTeslaCoilInchwSafetySwitch.aspx

[Ceiling cat]

(removed by author or community request)

[lightning r fun]

sorry about the crappy drawing.

it was the stupid paint computer program

[lightning r fun]

this is my plan

[lightning r fun]

i plan on making an instructable when i am finished

[Jimmy Proton]

i dont know, you need much more DC power to get the same results as AC power

[lightning r fun]

what if i used a flyback with an inverter circuit?
and i dont understand one thing, does a tesla coil run off ac or dc?

[Jimmy Proton]

i think you could do that
it is possible to run DC tesla coils but i used a 9.5kV DC power supply and i didnt work at all but with a 2kV ac power supply i got the results in the picture

[lightning r fun]

could i use a MOT to power this?

and would 2-3 NSTs in series make bigger sparks?

[Jimmy Proton]

yes you probably could use a MOT
i you put them in series you will probably overload the NST and if you dont depending on the combined voltage it may be to powerful for the coil, 6-15kV is the most common voltages for tesla coils, one should be good.

[lightning r fun]

my church asked me to do a display for halloween, and i was going to do a jacobs ladder, but i wanted a longer arc than the 1 inch that i have from a 4500v nst.
so i was wondering if i had one nst running to the input of another nst, if that would increase my power, or if i just connected one output of the first nst to one output of the other, then short out the other 2 leads with the jacobs ladder, if that would increase my spark length.

[Jimmy Proton]

if you put the NSTs in parallel you will increase the current, this will mean the arc will be hotter, by this you will be able to stretch the arc further.

[lightning r fun]

is there a way to make the arc longer, but keep the same current?

and could i run the output of the nst to a mot?

[Jimmy Proton]

i dont not have an answer to ether of those questions, do you have any MOT's by the way?

[lightning r fun]

not yet.
i wasn't going to get one until i knew for sure if i could use it with my nst.
i was gonna get it from a garage sale or something

[Jimmy Proton]

yeah me to but i cant find a microwave anywhere!

[lightning r fun]

where do you live?

[Jimmy Proton]

North Carolina, a few mile south of Raleigh.

[lightning r fun]

ALOT of garage sales around here
about 20 a week advertised in the paper about 10 more not in the paper

[lightning r fun]

im out in the sticks in oklahoma

[Jimmy Proton]

oh, ok, last saturday i was up near tthe mountains and i found an old microwave in a very very old house, as well as a bunch of other stuff but yeah i got a microwave!

[spark light]

DO NOT MESS WITH MOTS unless you are 100% sure of what you are dealing with! YOU WILL KILL YOURSELF!

[Jimmy Proton]

trust me I got this!

[lightning r fun]

my biggest problem right now is trying to find an inverter circuit(a simple one), to drive a transformer to give me my high voltage.

do you know of any such circuit?

[Jimmy Proton]

there is a circuit that consist of a relay that rapidly turns off and one which can drive a transformer, or you could use AC, here is a schematic....

[lightning r fun]

does a flyback driver turn your power to ac or pulsed dc?

[Jimmy Proton]

depends on your input, it will always be the same just different volts, current, ect.

[lightning r fun]

do know how to turn it to ac instead of pulsed dc?

[Jimmy Proton]

no i do not, ive been needing an inverter circuit but i cant seem to find any schematics for one, only AC to DC.

[lightning r fun]

i keep finding circuits for inverters, but they are 12 volt car batteries to 120v ac
i just want 12v dc to 12v ac

[Jimmy Proton]

hmmm, get a 12V wall wart with the current you desire and take out the rectifier and put it back together (if it has one)

[lightning r fun]

i don't understand.

[Jimmy Proton]

most wall warts have a 12V DC output, if you open it up theres a transformer and usually a bridge rectifier, if you remove the rectifier you will have AC output.

[lightning r fun]

what about this:

[lightning r fun]

but my whole point is to run it off a battery, not mains power

[Jimmy Proton]

The only thing i can help you with it pulsed DC, i dont know how to make DC into AC but i would like to.

[lightning r fun]

i'm no expert in making transformers, but if i were to make a small 1:1 transformer, with 1 coil with 22gauge wire, and the other coil with 10gauge wire, would i get higher current coming out the 10gauge side while running a flyback transformer through the 22gauge side?

[Jimmy Proton]

the thicker the wire the higher the current. You have probably heard lower voltage higher current and vice versa, well that can me modified by using thicker or smaller wire on the pri/sec coils of a transformer. im not sure if a flyback will work because the have low current output. (most of the time)

[lightning r fun]

i'll try it out, and if it works, then great!

[Jimmy Proton]

Hey what about a 555 timer oscillator? I was working on something and was using one of those and thought that it just mite work.

[Jimmy Proton]

there is a relay circuit thats turns the relay off and on super fast to make pulsed DC, or you could use AC, here is the schematic....

[lightning r fun]

another question, does the primary work better with a flat coil or an angled, cone shaped coil?

[Jimmy Proton]

for small coils like this you would a 90* coil for medium people sometimes use conical coils and for large you would use a flat coil because you dont want the arcs to strike it

[lightning r fun]

but i would need a thicker diameter secondary.

what i have now is about 1" diameter for the secondary

[Jimmy Proton]

anything about the size of a water bottle should work

[lightning r fun]

i believe i could get long sparks with a flyback(possibly ZVS) running to both a voltage transformer and a current transformer, then converting to ac.

[Jimmy Proton]

90* coils and most commonly used for tesla coils this small, and i used a 1" diameter secondary and you can try

[Dream Dragon]

I'm seriously concerned at the complete absence of any warnings on this instructable. Yes, it's only a SMALL Tesla coil, but it's still a HIGH VOLTAGE DEVICE which could EASILY KILL YOU. Maybe the author DOES know how to use it safely, but an explanation of the dangers of High Voltage Machines shold be considered an ESSENTIAL addition.

I also have some reservations about how the author sugests that some things are not critical, (Like the capacitance? And the Earthing connection at the Transformer?) Some of which could affect the safe functioning of the device. Do you know WHY you should use round headed bolts for your spark gap, and indeed for most of your exposed connections? If not, you should go look it up before doing anything else with this machine.

Some explaination of who Tesla was, how a Tesla Coil works, and some of the every day devices that use these principles would be nice.

Aside from that; for those who DO know about these things, this is an interesting explaination of a simple Tesla Coil, with some very clever use of available materials. The addition of more information for those who don't would make this a REALLY interesting Instructable.

[Jimmy Proton]

considering how small this is and how low the amps are it should not kill you, if you die from touching something it will probably be the power source witch they should already be aware of the dangers, i just used randoms capacitors and it worked fine(although i did update that), not all power sources have grounds, mine didnt so i dont need to include it in MY project, i dont know why round head bolts work better, someone else said it.

sorry if i sound aggressive...

[Dream Dragon]

I'm inclined to agree actually, it is a small, low POWER device and chances of death are similarly small, but NOT negligible, especially if another device is different from yours.  I wouldn't want to take the hit if someone built this and decided to sue. (It saddens me that it needs to be said; I believe that If you are going to do something you should be prepared to take the responsibility for the consequences, but unfortunately some people don't and are more interested in seeking compensation,).

Your machine could certainly be more efficient and someone else following this instructable with only slightly different materials on hand could end up with a very different beast.  As such I wouldn't reccomend testing it with your finger as you suggest in your final step, (quite appart from the fact that if someone got the circuit wrong or some of the components were faulty there could be mains electricity at that point) an earthed and insulated electrode that can be brought near to the globe without danger of drawing a spark to flesh would be safer.

Regarding the capacitors, it's a perfectly acceptable solution, and one that is widely used for modern coil circuits (well done for adding the other links there) but the capacitance of the circuit, combined with the ratio of turns in the primary and the secondary, along with the size of the spark gap will all have a significant effect on the output.  One modification you might consider is to use a heavier gauge of wire in the primary coil but leave it un-insulated, so that the supply and return from the tank circuit can be connected to it at different points, alternatively make several different coils with different shapes (cylindrical like this one, flat, and conic?) to see how that affects your machine.

As for "Round headed bolts" and generally avoiding any pointy bits, the key phrase is Corona Discharge which will sap the efficiency of your machine.

Generally speaking, I think you've been lucky to get this to work so easily, you just happen to have hit upon a random combination of capacitors, coil ratio and other aspects that all seem to work together.  Congratulations are definitely in order.  I assure you it doesn't always work like that.

[Jimmy Proton]

well, i must thank you for your advice but you are looking at it wrong, this is how I made MY tesla coil.