Picture of How to Build a Slayer Exciter

A Slayer Exciter is an air-cored transformer that steps up a very low DC voltage to a very high AC voltage. This creates an electromagnetic field around the coil that is capable of lighting up fluorescent and neon light bulbs. It is fairly similar to a Tesla Coil.

The Slayer Exciter was the brainstorm of Dr. Stiffler and GBluer a few years ago. It has since been modified and improved, resulting in a community of people whose hobby is to revise and improve them.

In this Instructable, I will show you how to build a small Slayer Exciter and will also give an explanation as to how it works.

There are several parts that make up a Slayer Exciter:
- The power source supplies the voltage and amperage.
- The driver circuit takes the electricity from the power source and prepares it for the transformer.
- The primary coil creates a magnetic field from the electricity.
- The secondary coil converts the magnetic field back into electricity and steps it up to a much higher voltage.
- Finally, the top load acts as a capacitor, greatly increasing the strength of the electromagnetic field.

The whole project only costs about $15 and can easily be completed in a weekend. It can be used as a centerpiece for the dinner table that will "wow" any family members or guests. It is also easily transportable which can make it a great conversation starter if you choose to bring it to school or work.

The Slayer exciter creates an electromagnetic field that may negatively affect electronic equipment in the immediate area; including pacemakers. Exercise caution and common sense when operating a Slayer Exciter.

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If your theory was correct, than the circuit would still oscillate if the primary was replaced with a light bulb. infact, the bottom of the secondary provides negative feedback, and this is what switches off the transistor.

grozybear1 month ago

I've been trying to build one these and I'm finally towards the end of it and I'm have a dilemma on types of wires, I have 30 awg but with out any enamel, and 26 with enamel which should I use? The primary is either going to be 22 or 20 awg if that helps.

you need the uncoated wire, and the fact that it is 30 awg is a plus, because the more turn s on your secondary, the more efficient it is.
ecozcelik23 days ago

What is the range of this ?How far can I light up a light bulb ?

yashd21 month ago


i arranged the circuit as you said but couldn't get UF4007 diodes..i used 1N4007 there any difference?? is it not working because of these diodes??

please help..or else can u suggest any other series of diode

blackhol1 made it!1 month ago
I made this circuit, and it works very well!! :)

Hello! I am a high school student and I am researching topics to do for my science project. Slayer Exciters (and tesla coils) intrigue me and I would like to know if you could explain how they work exactly before I consider it as a choice. You stated that: "A Slayer Exciter is an air-cored transformer that steps up a very low DC voltage to a very high AC voltage." Would you mind explaining what that means (like what is DC voltage and AC voltage)?

I don't mean to sound condescending; I want to help. If you don't know what AC and DC is, then explaining pretty much any part of this instructable isn't worthwhile because you wouldn't understand.

My advice is to use google. You can read, learn about, and teach yourself anything and everything you want through google searches.

So, first google Alternating Current and Direct Current (the AC and DC.) Read up on all the articles related to and linked in the AC and DC articles; everything related to electronics. Transformers, resistance and resistors, capacitors and capacitance, transistors, diodes, etc. Maybe get yourself an electronic starter kit online and follow the directions and play around. Once you have a base knowledge you can come to instructables like this one, instantly understand what you're dealing with, and have a good time doing it yourself.

I used to have no knowledge of electronics either, and believe me, projects like this you cannot do without an understanding of electronics. This isn't something that you can just follow the instructions and finish with a working product. In addition to knowing what the steps are, you need to know why you're doing each step.

Google and read as much as you possibly can and have fun!


I have followed the instructions as best as possible, but I am having a problem.

My voltage at the top of the secondary is the same as the input voltage. Any ideas?


aniansh3 months ago
Hello everyone, i want to make this as my science project. But i am confused. I can't seem to understand the need for two diodes in the circuit. What is the function of two diodes?
AdityaT33 months ago

***Please reply. This is an EMERGENCY***

Hello! I have been trying this circuit for a while now but I haven't succeeded in making it. I have used all the components you have mentioned and also tried replacing them with other equivalents but it just doesn't seem to work.

I get no voltage across the primary even when taking the input voltage up to 18 volts. And even when I do get a little voltage at times there seems to be no induction between the coils. I have used a 22 AWG coppoer wire for the primary (4-5 turns) and a 30 AWG wire for the secondary. The secondary is roughly 7-8 hundred turns (diameter of the secondary being roughly 1 inch and the length being roughly 7-8 inches).

I have been used a MJE3055T and also TIP41C transistors but didn't get any results.

I suspect there is a problem with the coils because it seems I have been doing everything correctly except for the coils.

Please help! I have to present this project on Sunday, Feb 1.

Thank you!

Chip Fixes (author)  AdityaT33 months ago
when you're running it at 12+ volts does the transistor heat up? Did you try flipping the leads on the primary coil? Did you try running it without a topload?

Thank you very much for the reply! I appreciate it a lot

Well, I have been using a heat sink with the transistor that could be why it doesnt really heat up. But the heat sink does get slightly hot after turning the circuit on for a while.

Yes, I have tried flipping the leads on the primary. I also tried the circuit without the topload.

The problem is that I dont get any voltage or oscillations across the primary.

But an LED lights up pretty nicely when it is connected in the place of the primary coil, i.e. to the positive rail and collector. So i assume that the transistor is working fine.

I also tried using a thicker wire for the primary but I still get no voltage across it.

I would really appreciate your help! Thank you!

Chip Fixes (author)  AdityaT33 months ago

The transistor heating up is a good sign and it sounds like the driver part is wired correctly (not necessarily working correctly though), especially with the LED test. Since you're using a slightly higher rated transistor, I would lower the value of the base resistor. Try 10k ohms, maybe 5k ohms (monitor the heating of the transistor when you do this). I'm thinking the transistor isn't being allowed to switch on/off.
Have you tried measuring the voltage from the top of the secondary coil?

Thank you so much, Chip!!!! The circuit is finally working!!! I got CFLs and Fluorescent tubes lighting up upto 3-4 inches away from the coils! It seems that once I replaced my old primary with a thicker one and the secondary with a nicely made non overlapping one, all I needed to do was check if the CFL was lighting up when brought near.. but I had failed so many times doing this that I just kept trying to measure the voltage and oscillations across the primary. Just as you said, I should have measured the voltage from the top of the secondary. Later when I was fiddling around with the circuit I found that there were sparks when any wire was brought to close to the secondary. As soon as I saw this I brought a CFL close enough to the secondary and VOILA!!! The lamp lit up! Thank you so much! Wouldn't have been possible without your help! The range has to be increased though.. you have any suggestions? Thank you! ^_^ :D

Chip Fixes (author)  AdityaT33 months ago

Oh good! Glad to hear it! Yeah the secondary coil is a critical part.

To increase the range, make a larger secondary coil with more turns and increase the input voltage.

ahmad.habib14 months ago

i can't find awg enameled wire in here(or maybe i haven't searched enough), but i find something that called as "insulator wire"(the wire used in insulator) and the diameter should be about 0.2 mm. Will it work if i used this cable instead of awg enameled wire ?

sorry, i mean inductor wire( the wire used in inductor)

What does a top load function as?

Chip Fixes (author)  thotthecreator5 months ago
It acts as a capacitor between ground and the top of the secondary.
fmarquis made it!6 months ago

I had tried this circuit before without success, when I was just starting building stuff. Browsing the site in search of something evil to build, I came back to this old favorite of mine. After spending more time finding where my secondary was hiding than breadboarding the circuit, it worked perfectly well on the first attempt.

I don't know what went wrong the first time... One hypothesis is the ambient humidity... Here in Montreal, Canada, it is already below freezing and tonight, the air is quite dry. Or it could just be related to my improved capacity to read/build from schematics!

The second picture shows what happens when you check the transistor temperature with very cold (like "I'm working in my shed by minus 5 Celsius") fingers. For a moment, I was happy that my transistor was holding the current quite well.

Actually, it was not. And this time, the smoke was not coming from a dead transistor, but from my finger. You can clearly see the silhouette of the TIP31C...

I learned many things tonight, the first one being : "Nothing looks like a cold transistor more than a burning hot one, especially to cold fingers.".

Lesson learned the hard way.

Thanks for the Instructable. I will try to make a more permanent one now that I know it's working!

2014-11-15 20.04.58.jpg2014-11-15 20.13.33.jpg

hey there thanks for the instructable. just want to know that how much the transistor can take without a heat sink. mine is a TIP31C CC039 m using a 50 k resistor

Chip Fixes (author)  thedevilhunternero6 months ago
I wouldn't go above 12 volts, but you can feel it with your fingers to see if it gets hot or not.

we use the tip41a transistor,a 100 nanofarads ceramic capacitor,10
kilo ohms resistor using a step down transformer of 220 to 12 volts, the
result is the aluminum foil as a top load will going to melt and the
transistor is over heating quickly. we connect the secondary coil to the
base parallel to the 10kilo ohms,then the the two 100 micro farads
parallel connect to the emitter and the ground.

can you add photo of driver circuit in detail pls and can we add capacitor

Roosafeedk8 months ago

I made it, but it does not have enough range. It can hardly light an LED that too when it is in contact with the topload. How to increase the output?

I am using 2 9V batteris, IN4007 diode, 1M resistor, and TIP31C

L1 has 6 turns and L2 around 800

Hello ;) I tried this circuit with tip29c and now with 2n3055 as well,
but none is working.For the 2n3055 I'm using the 47k resistor you
recommended and 12V, but nothing happens.Could you help me please?


heyy i tried to make it but cannot find TIP31C transister but i got a tip41c transister. will it.

and the second question is do you send me some material which have detailed explaination of its working of all component i am little bit confuse on its circuit.

question is that the led has two terminal +ve and -ve. so in air, how can he
get the both terminal current that is phase and neutral.

ferdinand002210 months ago

can i use a 26 awg wire as secondary and a 18 awg wire as primary???

what is to be the output voltage for wireless transmission??

please suggest a method o contact you other than instructables...

Chip Fixes (author)  ferdinand00229 months ago

26 awg is a little thick but you could try it and see, you might just need a larger input voltage. 18 awg for the primary is just fine. The voltage output can be calculated by the formula:
Vp/Vs = Np/Ns
Where Vp = voltage of the primary, Vs = voltage of the secondary (what you're trying to find), Np is the number of turns on the primary, and Ns is the number of turns of the secondary.

You can rearrange the equation to: Vs = Vp/(Np/Ns) to solve for the secondary voltage output.

irfanhabib1810 months ago

i tried to make it but at first the transistor was becoming very hot.. then i changed the poles or ends of the primary coil but it still did not work...... i supplied a 6v - 2 amp dc supply . the secondary coil was more than 1200 turns and primary was 8 turns... i used 1N4007 diode instead of the UF 4007 diode but all the other things are same... i tried to glow a 5watt - 220 volt cfl lamp ... please help me out

Chip Fixes (author)  irfanhabib189 months ago

You're going to need more than 6 volts to power a light bulb, try 12 or 18 volts.

AnubhabC made it!10 months ago

Hey Chip Fixes,

I have used 2 nine volt batteries. 1 LED(in place of diodes). about 1200 turns in L2 and 15 turns in primary coil(lower turns doesn't work properly). I am not sure of the value of the resistor i am using and no capacitor But the results are not satisfactory!

It is too weak as you can see in the images! What can i do? Whats your suggestions?? There is a detailed description here:

Chip Fixes (author)  AnubhabC9 months ago

You can try a few different things, reduce the amount of primary windings (I would go somewhere between 4 and 8), increase the input voltage, reduce the value of the resistor.

kshakkor9 months ago

hey uh chip Fixes,

i got transistor off TIP 35,tip 132,tip 135,tip 122,tip 122.will those work amigo.

Chip Fixes (author)  kshakkor9 months ago

TIP35 will work, you will probably need to add a heatsink of some sort though.

ferdinand002211 months ago

hi, Chip Fixes,

i cant get my slayer exciter to work.i did the same as you winding looks perfect.when i bring any bulbs near it,it wont light up.The current is flowing through the circuit.

Once the bulb had lighted,but was very faint. but then it wasn't lighting at all.It did not work.the components are working fine(tested using multimeter).

I think primary coil is the problem.I dont know how to adjust it...Please help...??

mine also has a heat sink and am using 18v.

Chip Fixes (author)  ferdinand002211 months ago

Try reversing the leads of the primary coil, you can also try using less turns on the primary. If that does not help, the transistor may be the problem.

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