# Make an Ultra Simple High Voltage Generator

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.
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## 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.

## Step 2: Wire up the transformer

Okay, before we attach the wires to the transformer, you need to take a look at it first...

The two leads of the transformer that are connected to the mains power source, is the primary (the high voltage side), and the other two leads are the secondary (the low voltage side).
We are going to connect the transformer in reversed, I mean the primary (the high voltage side) of the transformer becomes "secondary" and the secondary (the low voltage side) becomes "primary".

So we are going to connect the battery on the primary (the low voltage side) of the transformer and we will get some sparks from the secondary (the high voltage side)!

Right, attach the wires to the transformer!

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indy1970 says: 3 months ago
try this on get mechanical relay with a normally closed contact .
take the + from the battery go to the relay coil>> out of the relay coil to the transformer>> from the transformer to one side of the normally closed contact.
Then take the - battery to the other side of the normally closed contact. it will buzz the relay sending pulsed dc to the transformer stepping it up and giving you a higher frequency spark.
vgilankar says: 4 months ago
What if I got an old transformer? reply plz!
4 months ago
how would i use the transformer if it has four connections on one side then two on the other side?
vgilankar says: 4 months ago
If I try this with a 6v battery with other 3v battery would it be work same?
Erkel97 says: 6 months ago
since increase in voltage means decrease in amperage (right?) and amperage is the biggest danger to humans with electricity, Can this be used to shock people?
Jaguar93 says: 4 years ago
(removed by author or community request)
john12692 in reply to Jaguar934 years ago
transformers work with any type of electricity AC or DC its the flow of electricity that makes them work not the alternating current of AC though they work better with AC try it if you are any kind of tinker (which is what this website is for) you'll have a transformer lying around and can hook one up like this in 5 minutes plus if you are only momentarily connecting the battery to the the transformer it IS in actually AC if only momentarily
mikemmcmeans in reply to john126924 years ago
are you completely sure about the DC part. when you seee transformers in DC circuitry it's usually used along with transistors that turn the DC power on and off, simulating an AC wave pulsing the primary coil, magnetizing the metal core, then a pulse exits the trans on the secondary (or back out the primary (DCtoDC boost)) from my experimentation, if you connect DC voltage to a transformer it wont do anything at all, except blow some fuses/breakers. all that with no output at all on the other side, till you turn the DC input off. but if you're turning DC voltage on and off its not DC anymore.
you made sum correct comments but,,,, i dont think your correct in implying that if you switched DC on and off it simulates AC, if anything it simulates pulsed DC and yes if you turn DC on and off its still DC only pulsed,, also this leads me to believe that transformers are dependent on pulsed current in order to work and not necessarily on the change of current direction such as AC, so AC works not because its changing direction but because its having a pulsating effect above the zero line on a graph just like the output of a rectified AC. Al tough I read many times that it is the change of direction that induces a flux to the secondary,,hmmm but then why does a pulsed DC work? it has no change of current direction since it never goes below the zero line and stays in the same direction. something to think about i guess.
I am not an electronic technologist actually I'm a mechanical design technologist and welder but yep actually what I read was that you need AC in order to work a transformer properly but this is not because of the changing current, but I believe it is because AC is behaving like a pulsed wave and it is these ripples that generate the inductance in the coils and run the whole thing, so if you plan to use DC it will still work provided you make the signal a pulsed one via transistor or other devices, it seems even some mechanical devices such as 5 volt relays work too but I am guessing the output will appear pulsed rather than high repetition rates that are observed with solid state devices like transistors which make the sparks look continuous due to the high frequency. Or I could be wrong about the AC thing, anyone welcome to comment.
It actualy is because of the changing current, infact without changing current the tranfromer will not work at all.
wiki said,' Hypothetically an ideal transformer would work with direct-current excitation, with the core flux increasing linearly with time.[39] In practice, the flux would rise to the point where magnetic saturation of the core occurs, causing a huge increase in the magnetizing current and overheating the transformer. All practical transformers must therefore operate with alternating (or pulsed) current.'
http://en.wikipedia.org/wiki/Transformer

but i could have put that on wiki.
Tobor 2.0 in reply to jbrown797 months ago
wiki said, yeah, it also said phosphine (well not phosphine it was a different molecule) had the biggest "butt" of any molecule...
PINKmonster325 in reply to mikemmcmeans2 years ago
Well, yes, but it will still work if you make the voltage go on and off. (I don't know why, but it does in fact work)
john12692 in reply to mikemmcmeans4 years ago
ever hear of a joule theif? that uses a dc transformer
mikemmcmeans in reply to john126924 years ago
true, but the transistor pulses the voltage up and down, simulating an artificial AC wave, referencing 0V the ground of the system. sorry still AC power.
john12692 in reply to mikemmcmeans3 years ago
Magnelectrostatic in reply to mikemmcmeans4 years ago
AC = Alternating Current, it alternates between positive and "negative" current, your thinking of switched DC which is either on or off.
Plasmana (author) in reply to Jaguar934 years ago
Please be more specific what you are trying to say, you are speaking rubbish.
redcars101 in reply to Plasmana4 years ago
I found a transformer in one of my computer speakers, so am I suposed to connect the 9v battery to the output side and on the input side well be the high voltage?
egbertfitzwilly in reply to redcars1014 years ago
Yup, works like a charm.
redcars101 in reply to egbertfitzwilly4 years ago
did you respond to me?
egbertfitzwilly in reply to redcars1014 years ago
Yes, I was confirming that if you connect a low voltage on the output side you will get a high voltage on the input side. Since nothing is free there is a corresponding loss of current. There is also loss in the device. Both of these will vary signficantly depending on what the original intended use is. Your speaker transformer is probably an audio transformer. You might get better performance if you break open one of those cheap plug in power supplies.
milsorgen in reply to egbertfitzwilly7 months ago
"There is also loss in the device." My understanding is they operate beyond 90% efficiency on 60hz input, just food for thought. Definitely interesting devices to say the least!
redcars101 in reply to egbertfitzwilly4 years ago
I now have a digital alarm clock transformer. Is it good?
egbertfitzwilly in reply to redcars1014 years ago
Yeah that should work. What you really want to do is experiment. In this case your local library will be an invaluable resource. While they won't have much on digital all that old analog stuff is still valid. By going back and looking at the old AARL handbook and various electronics books you can find a whole host of useful circuits and technologies.
milsorgen in reply to egbertfitzwilly7 months ago
Lol, one more chime in here... Don't forget about your local used book stores. I have picked up tons of information on everything to little known meter tricks, to ICs, RF, DC power supply, Laser experiments. Don't think I've ever paid more than 7 bucks for a title either. One caveat though... it all tends to be from 70-80s but I find in some instances you get some more basic information than you would in some modern books.
1 year ago
uh oh big problem! how do you get the transformer to work with a dc current from a battery, they need an ac current to work.
You will still get arcs from the battery, but only when the power comes on and off.

Transformers as you might know, only respond when the electrical field going through it is changing. Transformers work with AC because the field is constantly changing. Now that's not to say using a DC supply the field is never changing. When you connect the power, the field does change, and the transformer responds, in this case with a brief pulse of high voltage across the secondary. You will not get a constant HV supply like you would with an AC input, but by simply turning the power on you will get the transformer to respond, albeit very briefly.
DanTheManTheMan says: 1 year ago
So how many volts actually come out of this thing???
anandcreativ says: 1 year ago
i thnik its gonna be awesome...
bubot17 says: 1 year ago
Whats the mA output? im planing to put this in my Thor Hammer >:D
tesla man in reply to bubot171 year ago
Im pretty sure that because you are increasing voltage, amperage decreases, so if a 9v battery cannot kill you, this could not. BUT if you decreased the out put voltage, then possibly
tesla man in reply to bubot171 year ago
Very interesting idea...
tesla man says: 1 year ago
When you say "static like sparks,"do you mean that it has very low amperage?
hore says: 1 year ago
Hey can i use electronic ballast or choke. is choke is the same with transformers.
sheepborg says: 4 years ago
uh i found this huge transformer thing while working at a camp that little kids take apart electronics. is there any way i can use this and if so how do i hook it up
tylervitale in reply to sheepborg1 year ago
That looks like an audio amp transformer. (gotta love them)
However, it may not be best to look for the biggest transformer you can find for this project. Typically, bigger transformers have higher voltage secondary coils.
What this essentially means is you'll get a lower voltage. If you put 9v into a 120v/9v transformer, you should get 120 volts out. If the voltage is higher, like say, a 120v/50v transformer, then putting 9 volts in will only yield a fraction of the 120 volts you SHOULD be getting. Conversely, if you put 50 volts into a 120v/9v transformer, you're going to get a LOT more than 120 volts out! (provided it doesn't fry.)
bcantley2010 in reply to sheepborg2 years ago
what is on that blue sticker?
what did the x-former come out of?

I would partially feel safe amusing that where your thumb is placed would be the primary windings and the secondary windings are on the right. Yes there are more than 4 connection points but try to use the pins that are farthest apart and ignore the pins in the middle on the secondary. I would assume the same for the primary side but it looks like i see the 2 closest pins by your thumb could be the connection points for the primary.

there is no harm in trying.