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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yashs1420 days ago
Bro help me plz
i made this with all new parts and under your supervisions but my CFF bulb lights in the the begining and my transistor gets hot but its not a major problem but after sometime my bulb doesn't glow i found that my transistor is not working properly so i changed it with new one and again starts working but same problem happend again i changed 5 transistors but problem is happening i also used heatsink with my all transistors.
help me plz beacuse i don wnt to change transistor again and again

I'm not very familiar with slayer exciters but want to build one which air core diameter is 4 cm, using 0.25 mm (30 AWG) thick enameled wire as in this instructable, but using 850 T on secondary. Will it have a better range if I use more windings on the secondary? And I don't know how many turns on the primary should there be if I put 850 turns on the secondary, is there any equation for this ratio? Thanks!

akashs201 month ago

I did everything as told & my transistor, diode &resistor are heating up but my coil wont work. My science fair is in 2 days so i need HELP!! fast.

Chip Fixes (author)  akashs201 month ago
If everything is warm to the touch but not hot then that's a good indication that the driver circuit is working properly. Try flipping the ends of the primary coil around and if that doesn't work, try changing the top load.
akashs201 month ago

I did everything as told & my transistor, diode &resistor are heating up but my coil wont work. My science fair is in 2 days so i need HELP!! fast.

mkamil07 made it!2 months ago

Everyone please, mine is not working :(

I'm new on electronics and also in instructable.

So i followed exactly like in the diagram (except the switch), so at first i am confident mine will works too..

need for my project, am i doing something wrong?

1) Whenever i have just done connecting the wire to the battery, i touch the driver circuit, and the transistor was hot! I don't know why but i haven't switch it on.

2) I am getting panic. So i release all of the wire i've just connected.

3) I just want to know why its not working, so i added them again and checked it with my lamp (it's not working)

4) Try with LED , still not working

5) Touch the transistor, is not getting hot anymore.

Really appreciate any recommendation, don't know how to fix this..

Then, is my driver circuit right? Really i have no one here to ask for.


Transistor might dead.Try to swap the primary's connection and also Double check your connections.Hope this help. Good luck and Happy building. :D

borara1 month ago

When i connect top load my coil wont work, it works without it.

MrR21 month ago
This thing does'nt works
I dont understand how to arrange tge circuit on breadboard.
Please help, this is my first time on instructables and electronics too.

Hi, i am willing to try to help, do you have a specific problem that you know of, or is it not just working?

Also, a solderless breadboard isn't the best way to due this as many are rated for relativly low amperage.


MrR22 months ago
Mr. Fixes
Are there any altranatives for the length and thickness of the wire for the coil.
MrR22 months ago
Mr. Fixes
Are there any altranatives for the length and thickness of the wire for the coil.
MrR22 months ago
Are their any replacements for the thickness and length of the wire
Febin 012 months ago
Hiii iam Febin....sir please help me...I'm confused with specification of primary coil
yashd24 months ago


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

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

SohaibH yashd22 months ago

Use UF4007, they are ultra fast.

SohaibH made it!2 months ago

I followed all the instructions and have made it :)

IsaacM72 months ago

Hello I really want to build this and I have been trying to get this circuit to work for some time, i
used all the same parts as you did except for the diodes I used 2 LEDS. When
I tried it the circuit LEDS didn't light up and got no voltage in the

secondary i already tried switching the primary leads, I am using a 15v
supply and have used many different resistor values without success and
the transistor does heat up please help.

My cfl glows sometimes and sometimes not.. Whats the problem? Using all fresh parts!
PlasmaGuy1013 months ago

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.

grozybear4 months 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.
ecozcelik4 months ago

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

blackhol1 made it!4 months 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?


aniansh6 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?
AdityaT37 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)  AdityaT37 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)  AdityaT37 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)  AdityaT37 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.habib17 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)  thotthecreator8 months ago
It acts as a capacitor between ground and the top of the secondary.
fmarquis made it!9 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!

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