Have you ever wanted to build a high voltage devices to make sparks like Tesla Coils, Marx Generator, and so on.. But find it too compacted or difficult to build?

Well, this instructable is for you! It can make create a few kilovolts of static-like sparks, and best of all... You can make it with only two things to make it, a battery and a simple mains transformer!

Before you continue, you should know a little bit of information about transformers, click here to find out.

Step 1: Get the things!!

Like I said, you need only two things to make it, well, actually, three things - some wires.

  • 9 volt battery.
  • Mains transformer
  • Wires

The mains transformer, you can find those in just about any mains powered electronic devices, like VCR's, stereos, and stuff like that, you can also use a wall wart if you want. The best mains transformers you could ever use is found in digital alarm clocks.

Unfortunately, I burnt up all of my alarm clock transformers while ago... :( So I will have use a transformer from a VCR.
<p>Thanks! Does the amperage of the transformer matter?</p>
<p>Thanks so much!</p><p>I am just wondeirng how much voltage is coming from the spark end, it doesn't seem to be 240 and I don't have my multimeter at the moment :P</p><p>I used a 240 to 6v Transformer from a battery charger :D</p><p>Again thanks for your amazing guide! :)</p>
<p>What would happen if i would submerge it in oil and attach the secondary to 220V mains?</p>
<p>can you make this work for something like generating plasma</p>
<p>It generates plasma with every click</p>
I used to do this as a kid. I once used the output of my hifi as the source, then held the electrodes and felt the music in my muscles. It was fun, but painful.
In hindsight, i think it was actually quite dangerous
<p>Well, i did that with a b/w flyback and a 9V battery and liked the feeling, now i think that it isn't that good for the heart...</p>
Does polarity matter? I'm havin trouble getting a spark (using alligator clips). I have also adjusted it to run on 27 VDC
Can anyone explain how a tesla coil works?
Like a transformer, it has a primary and secondary winding. Except, the secondary is left oen, effectively it has a near infinite impedance which allows it to generate really high voltages.
An ac wall wart is preferable
<p>could i safely build this using the transformer the right way round (ie with mains voltage) and use the capacitor out of the same vcr (the 1st big one) to charge up then with a switch (to control the discharge from the capacitor) to work the same way (as the transformer i have takes 240v ac in (at 3,5 10, or 13 amp depending on the fuse i put in the plug) and out puts 17.5v ac) so i want to know if i made this set up would it be safe (i would be using a mains ac switch which i can put on a long run of flex so that im at a safe distance) ???</p>
<p>It takes one thing to harm you when it comes to electricity, but it takes a couple other things being the right condition for that to happen at all. What harms you is current flow. But you have to be in the path of the current, with sufficient voltage to push the current through you, before the trouble starts.</p><p>Once all of that lines up for you though, look out! You could cause yourself cardiac arrest by inducing an arrhythmia to your heart, or just cook yourself internally if conditions are really bad. Although some folks also have suffered flash burns from contact with high intensity electricity too.</p><p>Don't be the hot dog</p><p><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/XB_wRqGLJXE" width="500"></iframe></p>
this is not possible. its fake. you cannot use a ac transformer with a DC source. u need to convert the DC source to ac before you hook it up to the transformer. the circuit doesn't make sense.
<p>The switch is good for one pulse. As the field grows in the powered coil it will induce a current in the other transformer coil. But as soon as the powered coil is saturated no more current will flow in the coupled coil. So you get one zap per switch closure.</p><p>This is not only possible, it is also how gasoline engine ignition systems function too. It is what makes spark plugs spark.</p>
<p>You can also make a DC-AC converter easily with a vacuum tube in the circit</p>
<p>it is possible to use an AC transformer with DC. The trick is to use pulsed dc.</p>
<p>dc to ac is not possible without a capacitor and diode . isn't it ?</p>
<p>if you just keep pressing the button it makes an ac current every time you press the button</p>
<p>You make pulsed DC, not AC. The transformer doesn't mind, but there is a difference.</p>
<p>You mean ac to dc. Yeah it isnt possible. But you don't necessarily need dc for this experiment specifically.</p>
<p>Of course AC to DC is possible. DC is rectified, and filtered AC. What isn't possible is constantly inducing a current through a transformer with steady DC. That violates the laws of physics as we now understand them. But we can induce current in a transformer with pulsed DC. Which is exactly what is going on in this article.</p><p>When the switch is closed a magnetic field grows around one coil of the transformer and its moving lines of magnetic flux cut across the other coil, and induce a current in it. The ratio of coil windings to each other establishes the voltage differential between the coils.</p><p>Here the secondary winding of a line step down transformer is energized to induce a higher voltage on the primary side. We made these things when I was in grade school, and called them shockers.</p>
<p>You can if you have a vacuum, like a microwave or a vacuum tube. It utilizes the Negative Resistance property. Really fascinating subject.</p>
<p>I was taught in electronic school that in order to transform ac to dc you need a transformer along with a full wave rectifier (bridge rectifier) ( in which is four diodes), and a capacitor to filter out the remaining ac ripple. Now from dc to ac you need what is known as an inverter. </p>
<p>yes that's totally right how ever with a capacitor with a fixed discharge rate you can make dc ripple like ac ( it will not be a.c. for that ripple you would need a flip flop i.c. control chip to keep swapping the d.c. back and forth to match the rate at which a.c. flips (or ripples) source me electric, electronic and software engineer </p>
<p>How would you make a simple AC generating circuit to make it continues?</p>
<p>You do not need AC, you just need to break the circuit repeatedly. By break I mean disconnect the power, then reapply it. Sort of like a self flipping switch. You do that with an oscillator circuit. The simplest I can think of would be based on a 555 timer. You have to be careful about inductive kickback though, or back EMF, from the collapsing magnetic field of the transformer. You use something called a flyback diode to counteract that.</p><p>I made something similar last week, and it is still on my breadboard, so I'll take a picture of it. I annotated the image somewhat, to name the main parts.</p><p>The 555 timer makes a square wave, which is a stream of on, and off pulses. Those pulses trigger the power transistor to switch the Relay Coil load attached to it. Instead of the Relay Coil you could directly energize the coil winding of a transformer too.</p><p>The flyback diode is the little black circle behind the Power Transistor. I labeled it in green.</p><p>I made this circuit to move that piece of CD up, and down, so I could point a laser at it, and it would make a pattern with the reflected beam. Just in case anyone is wondering. But it would work to move an electrical field inside of a transformer too. Making an automatic spark gapper.</p>
<p>What is missing here is the fact that he has to turn the switch on and off repeatedly. This will cause the DC to pulse through the transformer. In effect it creates the same effect as that of an AC current (well almost as the flux will rise and fall everytime the switch is turned on and off but without the negative side of the AC sine wave). Then you will occasionally see a spark jump of the high voltage side. The trick here is to turn on and off the switch repeatedly. :)</p>
<p>Thanks for your great effort you have made to me ...but can I replace 9v dc of battery by 9v ac ?</p>
Yes you can. It will generate sparks at ac frequency.
thanks... God bless you ... your site has good information and very safe ... I have no risks.
<p>thanks ... God bless you.</p>
<p>I got a transformer from a fluorescent lamp, but it only has 3 pins, what do I do?</p>
if you leave it on, will the spark stay on. i mean like if you were to hold down the switch instead of tapping it.
No, that wouldn't work because the reason the transformer works is because of alternating current. Electricity is created by an magnetic field that alternated back and forth causing an electron flow. if you just hook it up to the battery and leave the button on then it will create one high voltage pulse from the initial magnetic field but since it doesn't change there will be no voltage continued after that first pulse. that is why you need AC power for transformers. I Suggested a 555 timer because it alternates and would be good to trip a transistor or relay to act like pressing a button really fast. The primary coil in the transistor creates a reverse current feed back after you stop applying power to it so i keep frying the transistor even with a diode at the end. Does anyone know how to make this work better because it is a great idea to step up voltage.
<p>Use a Hexfet to drive the coil and the 555 to drive the hexfet. Connect the source through the hexfet direct to a battery to absorb the back emf spike by adding a capacitor into the circuit, then through a diode directed only to the battery post for the spike's concern.The higher charges will concentrate and release into the battery correctly. If the voltages are ultra-high, I would consider putting a ground initiated back emf &quot;Spark Gap&quot;, which you would do by adding additional circuitry that would activate instantaneously upon removal of power to the transformer coil. This would at the same time connect the transformer coil, cap or caps (as a bank) to absorb the charge from the back emf pulse, and at the exact time of avalanche, the other side of the transformer coil is disconnected, and the battery is connected to the back emf path to absorb and suck up the energy safely. If you leave the transistor in the circuit while removing power, unless you build precautionary circuitry, I'm sorry , but the spikes vary with sharpness, and as you know are very destructive. If the waveform gives this very sharp spike while shutting off, the voltage gets more powerful and could easily douple , triple , or even quadruple, sending the ultimate surge back into the transistor or even further, with high enough voltages to jump to the controller, 555, or whatever chip is used, frying that.</p><p>Take a few minutes and Google &quot;back -emf protection circuits&quot; to see what there is to offer. They may have these circuits printed right in the product datasheet. Sometimes before designing a circuit, I look to see what great products are out there that have the schematic published online, which drives a coil , adding protection. Some manufacturers have a discharge pin of some sort that you could add a resistor to ground on the output, which protects the unit against back emf and other electronic anomalies that could happen as a result of powering down a large inductor coil. Most electric motors that use relays have grounding resistors to eliminate this voltage build up. Some circuits out there have already been created to use these pulses for charging things, so, my guess is the battery will be the best protection one will find, possibly even caps, which I use without any issues at all. The diode has to push the current the way you wish once you disconnect. </p><p>Marc</p>
<p>Why don't you just follow the KISS principle and add a capacitor(and perhaps a resistor) in series for the primary circuit?</p>
wait since AC already alternates its current doesn't that mean the current is already pulsed in the transformer? Therefore it already creates fast high voltage<br>pulse. Why do u still need to add a transistor to further pulse the current
That only happens if the current going through the low-voltage side of the circuit is oscillating. If it were a constant DC current, you would only get a momentary spark when the primary discharges into the secondary as soon as you release the switch.
sorry did'nt think it through I do that occasionally
it actully wont, im not sure why, but ive built one and it dosnt waork that way.
<p>Great job Plasmana. An excellent example of high voltage induction. For those whom electrical knowledge is lacking, a simple, cheap and safe way to observe a spark. For those who say this doesn't work.......you need to read more carefully. Plasmana said to TAP the positive terminal....not TAPE it. Plasmana did not say that you would get continuous sparking. You get one spark for one tap. Turn the lights down and you will see it. Thanks Plasmana. And 73's.</p>
<p>hook up a moter to make the shock consistent.</p>
<p>That's pretty awesome. I am looking into building an electric ignition spark system for an aerosol based flamethrower. (With a pistol grip for spray painting and whatever aerosol that is flammable). I am thinking this idea would work great. Thanks!</p>
<p>cool im using mine to build a ultra high voltage emp so far it only works on small items like iphones my sister killed me when i broke her 5S </p>
<p>This won't work. DC does not transform in this way. At most you might get a very brief spark when you disconnect the battery from the EMF collapsing in the opposite polarity.</p>
<p>if you want bigger spark than </p><p>Use a 9vdc to 240vac transformer then 240vac to 600vac transformer</p>

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