A slayer exciter is basically a small solid state tesla coil, usually a one transistor design. The circuitry for it is simple. One of the first things anyone who has built a joule thief will notice, is that the circuitry is very similar. The biggest difference is that the small transformer or inductor has been replaced with a primary/secondary tesla coil configuration, and that the feedback is capacitively coupled. (There is a good abount of capacitance between the 'top' of the coil, and ground.)

There are many awesome thing these exciters can do!
they can:


  • neon lights!-----------------------------------------(several feet away)
  • florescent tubes!----------------------------------(within about a foot)
  • CFL's!-----------------------------------------------(within about a foot)
  • EL wire---------------(it does not work well for me. If anyone tries it, please tell me your results!)
  • LED's!-----------------------------------------------(across the room if done right)
  • and even small incandescent lights! -------(with an L3 coil)
  • paper with pencil markings -------------------(before it catches fire!)

Burn and ignite:

  • candles
  • wood (pencils)
  • human flesh (now my fingers smell burnt)
  • paper


  • crappy / half dead LED's
  • bacteria
  • sensitive electronic equipment (phones, computers, SD cards, CD's, blu rays, flash drives)
  • someone else's stuff


  • ion wind motors
  • the coolest lantern or light on earth
  • fires
  • plasma cutter

►Make following electronic equipment go crazy:

  • calculators
  • watches
  • digital clocks and alarms
  • devices with capacitive touchscreens (PlayStation VIVA, smartphones, feature phones, tablets)
  • UHF remotes

Transmit wacky sounds (loads of EMI) to:

  • AM radio
  • FM radio
  • shortwave radio
  • HAM radios possibly
  • TV interference

Here is how to make a my version of the more powerful exciter (These videos were made awhile after this intructable, so the only issue with it is thermal management.) Please do not get the instructions in this video confused with the instructions for the later TO-92 one in the further steps. Different bias resistor values should be used for either of these 2 versons.

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Isaac_7 days ago
What are the pins on the ds0026?
-max- (author)  Isaac_7 days ago
Isaac_ -max-7 days ago
thank you
In your Simple SSTC design, what do the blue arrows indicate?
-max- (author)  atharva4rever10 days ago
They represent common signal ground connections. These all connect to the negitive if the power supply. It might be helpful to you if you print some schematic part charts to help out if you plan to build this. The link below shows you the most common types of ground connections.

Thanks Sir.

the mosfet slayer exciter doesn't work, the transformer hums loudly and the switch arcs when turned off. Any ideas?

-max- (author)  PlasmaGuy10115 days ago
Either you have a dead short circuit somewhere or you killed the MOSFET, and in my experience, the failure mode for MOSFETs almost always low impedance (permanently on.).

You NEED to use IRFP250N's or better, and you NEED to have input protection to the gate as well as the input for the MOSFET driver. I tried 2 IRP640's in parallel and both instantly blew. They simply were not good enough.

what do you mean by input protection?

-max- (author)  PlasmaGuy10114 days ago

http://www.semtech.com/images/datasheet/transient_voltage_protection_of_mosfets.pdf but for the DS0026.

ChinmayC118 days ago

Can I use 12 V 1 A power supply with TIP31C transistor, 10 k resistor and 100nf capacitors?

If not what should I do??? Please relply fast..

-max- (author)  ChinmayC118 days ago
Probably yes, and if it does not work then probably not.
BhaskarJ123 days ago
Can i make it with this ignoitor see th link --http://www.ebay.in/itm/321811642592?_trksid=p2059707.m2929.l5391&redirect=mobile
SKtesla1 month ago

Thanks for the great instructable max! I got my exciter working and I can get a consistent arc without a top load. With a top load on I am able to draw arcs as well as light a CFL. When I tried to light an incandescent, I was able to see a small arc from the filament but it is nowhere near as impressive as your video.

This is my setup:


12V 5A power supply

1K pullup resistor.

100nF 500V ceramic caps (2 in parallel)

4 turn primary and a big secondary.

I wanted to ask how I can up the power on this coil. Also, could you please put up an Instructable on making the MOSFET version? I'm already looking for bigger sparks! :D

-max- (author)  SKtesla1 month ago
When I perfect my MOSFET version, I will make a video instead. I like the video format better. I just bought some another pack of 10 brand new shiny IRFP250N MOSFETs to burn though while prototyping.

To up the power, use the TIP3055 connected to a huge fan-cooled heatsink, use some large film capacitors or MKP capacitors (around 1uF or more) as well as some electrolytic 1000uF or more all in parallel with the power supply, and have the connections between the all the points in the circuit as small as possible. Alligator clips are not the best, they are a little too long.

Adding a really low value (10's of picofarads) high voltage ceramic or similar capacitor across the coil and adjusting the value of it as well as the turns ratio of the primary is needed to get the best performance. Getting this right is critical. Too much capacitance and too many turns and your circuit may not work at all. Too few and it will not be very powerful.

Cranking up the voltage to 24V will also make the output WAY more powerful, at the cost of using a LOT more power and greatly increasing the chance of killing the transistor.
SKtesla -max-1 month ago

Thanks a lot. I am looking forward to seeing the video soon

I have ordered a 5-pack of MJE3055Ts. I will try them out before going for the TIP3055. How do these two compare in your experience? I also have a 2N3055 I can try though I don't like the TO-3 package. I don't have a heatsink yet so I've been running the exciter for very short durations since the transistors get really hot. I will be buying a heat sink along with a barrel jack so I can wire everything neatly on perfboard. What do you think of this heatsink. Too small? I will get some caps while I'm at it and try what you suggested. I don't have a 24V supply on hand now, I will buy one if it seems necessary.

SKtesla SKtesla1 month ago

I was also curious, is it possible to audio modulate the slayer exciter? Also, does the MOSFET version provide superior performance even at 12V? I am working on a proper SSTC but I want to run this with my current setup meanwhile. I only have a 12V power supply now though.

-max- (author)  SKtesla1 month ago

Yes, that heatsink is way t0o small if you want tesla coil results (one inch arcs or longer.) You basically need a CPU heatsink, and a way to mount the transistors firmly. I now use a heatsink ripped out of an old Xbox rather than the one used in my old slayer exciter video. You can see the size of the heatsink in my more recent flyback transformer video. If you want one about as powerful as the TO92 version (in the 'able with 3 2N3904's in parallel), then the heatsink you found online is plentyful.

SKtesla -max-27 days ago

Hey Max. I've started collecting parts for a big SSTC, but i want to up the power on this coil first. I have got an IRFP250. I also have some UCC37321 and 37322 MOSFET driver ICs. I wanted to ask if the UCC37321 would work instead of the DS0026 (since they are both inverting)? Thanks!

-max- (author)  SKtesla1 month ago

I can't really tell if the MOSFET is much better or not, the performance of the circuit really depends on how well it is tuned, there are many variables that determine whether or not it is tuned, including how close things like your hand are to the circuit. In general though, yes. I want to say it is also more efficient, but I have no quantitative or measured evidence.

The most obvious way to modulate such circuits would be to modulate the voltage of the supply rails. The difficulty of doing so will vary depending on what power supply you choose. This might be easy with a simple linear voltage regulator by interfering with the negative feedback loop injecting audio "noise" to it. On my ZVS driver, I audio modulated it by adding a lot of turns of wire to the big inductor in series with the primary, and injected audio into that forcing the voltage to the circuit to be modulated.

ElectroBOOM has a much better schematic that already supports such modulation in a much more integrated manner.

SKtesla -max-1 month ago

Thanks. I will look for a bigger heat sink. I am collecting the parts to build a SSTC based on Steve Ward's SSTC 5 or the Kaizer SSTC 2. I will be able to modulate that. I have seen the ElectroBOOM one (love his videos) but the parts used are not easily available for me. BTW, do you know of any good source of 30AWG magnet wire with international shipping? EBay doesn't seem to have any options.

-max- (author)  SKtesla1 month ago

I bought my wire from eBay, so I really can't tell you much in regard of buying wire. Others often salvage wire from large transformers and even motors.

ChinmayC11 month ago

While winding the coil my copper wire ends at half. I bought some new copper wire to continue winding. Now I am facing the problem to join the two ends of the copper wire i.e. the new one and the old one. What should I do ? Should I solder the both ends or join them by an electric tape. Deadline of my school science project is in 2 day please reply fast.

And another question is that how to power it ? Can I use a 9V battery?

Please answer fast..Thanks

-max- (author)  ChinmayC11 month ago
the sloppy coil in my videos and instructable is made up of at least 3 separate magnet wires, and I soldered them together to continue winding it. In fact, the top quarter of it is not even the same color, and some of it isn't even the same gauge!!!

However, it is NOT good practice to do that. YES, it will be fine, but it will look sloppy, it will be 'leaky' (sharp, exposed metal at the junction will cause corona and leak away the electrons). If you want the best peak performance, try to avoid doing that.

It is a good idea to coat the entire coil in enamel after finishing it, this will help increase the dielectric strength of the coil and "seal up" areas that have been joined. I added additional electrical tape on some areas to do the same job.
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.

-max- (author)  akashs201 month ago
Just keep troubleshooting it until it works. It took me weeks and several attempts at rebuilding the circuit to figure it out myself what problems I had when I made this myself. Without info on your circuit and setup, all I can do is refer you to the troubleshooting page.
akashs20 -max-1 month ago

transistor = TIP31C Resistor = 47000 ohms Diodes = UF4007

my circuit heats up but when i connect it to the coil, it turns cold. Don't know whats wrong

-max- (author)  akashs201 month ago

"my circuit heats up but when i connect it to the coil, it turns cold. Don't know whats wrong" Based on that description, it sounds like you wired it incorrectly. Almost like you connected the coil between the base of the transistor and ground.

-max- (author)  akashs201 month ago

Get rid of the diodes, they are not necessary and I find they often cause problems. Test or replace your transistor to verify it has not burned out. Increase or decrease the number of turns on the primary, or reverse the polarity of the primary to see if that is the issue. 47k sounds a little high. Try 4.7k.

akashs20 -max-1 month ago


See whats wrong in it

-max- (author)  akashs201 month ago

Have you removed the diodes like I said? Also check that you wired the transsitor correctly.

JasonP17 made it!2 months ago

Well Took me a minute to get it right and tuned, but my 1st Slayer exciter ..

Wrapped on a CD spindle,#30awg wire 250t s, 5t p .. 9v battery setup.. (not very powerful but works..)

#2 / 3 & 4 all work well with this circuit.

using 3 TIP29c transistors (had them in my box) paralleled

#2 ~~ #30awg wire, 540t s, 3t flat spiral primary, 1.5" former

#3 ~~ #30awg wire 720t s, 4t primary (horizontal setup for playing with Tesla's magnifying transmitter setup). 1.5" former

#4 ~~ #40 awg wire (complete pain in the arse to wind without errors)

2000t secondary, 20t primary Bifilar wound, 1.5" former.

#5 ~~ #40awg wire 750t s, 8t primary, 3" former..

I gave #1 to my nephew (10y/o) to play with and get excited as it only runs on batteries.

Overall, good tutorial! I really want to throw sparks though... I made the fat one into a sgtc, would not breakout on its own but 4" lightning when getting ground probe close to topload breakout point .. :/

JasonP17 JasonP172 months ago

Also for those looking for small easy toploads, Soda cans work well, and can be taped together for larger loads..

-max- (author)  JasonP172 months ago

If you REALLY want to throw some large sparks of at least 4 inches, and avoid the noisy SGTC, I recommend this circuit, if you have the parts already laying around.

This is actually where the development of the original slayer exciter circuit has led me. I initially replaced the NPN transistor with a MOSFET, since they are better suited for switching applications*, and it was in a easy package type (TO-247) to mount, and already mounted to a large heatsink. I suspect because the input has some significant enough input capacitance, has a really high input impedance, and since MOSFETs need a relatively high gate voltage to turn on, the standard circuit didn't work.

My next thought was to use a comparator as a buffer, but I did not have any of those, then I found some even better dedicated MOSFET driver chips, designed for that very purpose! I used the DS0026, which is what I had on-hand! Some messing around to make the oscillation stable and strong, I came up with the first design below in the pictures. I was able to power this without issue up to 50V.

In the 2nd version, I simply added a "interrupter" to PWM the power rail of the DS0026 so that way the RMS power draw was less, and since I am no longer loaded down my transformer, the voltage has risen to 40-50V across the power rails. Consequently when the circuit kicks on and runs for the short duration, I get incredible arc length!!!!!

The interrupter that I choose was simple a astable 555 since practically that is the easiest oscillator for me to make work and breadboard up quickly. I'm driving an emitter follower transistor which turns on and off the DS0026 which in turn mean that the circuit only works 10-20% of the time, allowing some down time for the capacitor to charge back up and gives the small poor transformer and MOSFET a break. The duty cycle is of course 10-20%, while the frequicy is about 10Hz-100Hz depending on the capacitor.

Solid State Tesla Coil Slayer Exciter rev 2.pngSolid State Tesla Coil Slayer Exciter.png

i bought all the parts and im going to start building now. its going to be powered off 170 vdc, so i should have a 10 inch spark.

-max- (author)  PlasmaGuy1012 months ago

170V!? I barely had any success at 50V. I predict that this circuit will just blow up everything and possibly blow a circuit breaker. Start at 12V for this circuit and work your way up to 24V, 36V, 48V, etc.

At voltages higher than 36V, you will NEED to replace the "12V regulator" made with a zener diode and some resistors with a switch-mode regulator or DC to DC converter. Also you will NEED to get much higher power transistors, I have blown all of my IRFP250's, so my plans for making a video of the circuit are delayed.

ok, i have a big 21-42 volt 5amp psu that i can power it with. the irfp250 is rated at 200v so why won't it work at 170vdc?

-max- (author)  PlasmaGuy1011 month ago

Is the PSU a SMPS (Switch Mode Power Supply)? one of the lighter smaller ones (with tons of circuitry and lots of small transformers, inductors, and capacitors) Or is it a linear type (the simple kind usually made up of one huge heavy iron core transformer and a few diodes and huge capacitors.)?

You may run into issues with "foldback current limiting" and "short-circuit protection" sh*t kicking in and abruptly causing the output of the power supply to shut off. I have been using a modified (hacked) xbox power supply which is a SMPS but all that protection has been bypassed with some mod wires.

its just a huge 42v transformer with a rectifier and 65v 33000uf smoothing capacitor

-max- (author)  PlasmaGuy1011 month ago

Good! You shouldn't have any issues with it! With that you should be able to get very similar results to me. What chip are you using as a substitute for the DS0026?

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