Introduction: Easy SSTC, Slayer Exciter on Steroids!

Picture of Easy SSTC, Slayer Exciter on Steroids!

In this instructable, I'll show you how to build a REALLY powerful version of the slayer exciter circuit! This design is powerful enough to be considered an SSTC, or Solid State Tesla Coil! It can throw really hot electrical arcs of plasma over 3 inches long, and has the capability to be modulated! By modulating the circuit with a square wave with a frequency of around 60Hz and 10% duty cycle, you can achieve sparks that look like a small Vacuum tube tesla coil, and also greatly reduce power consumption!

If you prefer to watch my video tutorial, or just see what this thing is capible of, watch the video below:

Step 1: The Schematics & Plans!

Picture of The Schematics & Plans!

Compared to the normal Slayer exciter circuit, this circuit has some major changes. The biggest one that drove the rest of the design was switching out the normal BJT NPN transistor for a MOSFET. I used 2 IRFP250 MOSFETs in parallel to improve the current handling capability and thermal characteristics compared to the comparatively wimpy MJT3055. However, using FETs presented an issue with the gate-drive, as the gate could no longer be driven directly by the feedback. (Most likely due to a impedance-matching issue with the gate acting like a capacitive load) To fix this, I simply used one of the very many DS0026 MOSFET driver inverted buffers I had in the parts bin.

I also added a resonant tank capacitor across the primary to make use of the EMF flyback and help the circuit achieve resonance, and a 10K --- 100K resistor across the input and output pins of the DS0026 to increase stability and reliability of the oscillation. Since the input to the DS0026 is susceptible to the uncontrolled voltage transients from the feedback, I also added a few 1N4148 diodes to shunt voltages that go 0.6V above or below the supply rail. If these are not used, the DS0026 will die within seconds of operation.

Step 2: Choosing a Suitable Power Supply

Picture of Choosing a Suitable Power Supply

To power this circuit, there are many limitations on the type of power supply that can be used. For starters, Linear or unregulated power supplies MUST be used. Most modern Switch Mode Power Supplies (SMPS) will often not work as inrush current and other current peaks will cause them to go into foldback current limiting mode, which basically means that they turn the output off most of the way as a form of short circuit protection until you reset power to them or when the load is disconnected. Therefore unless they are modified/hacked, they will not be suitable. and as for the small little wall bricks, FORGET about those. Even the older unregulated transformer based ones are simply not big enough.


Now to achieve the results I did, you are going to need one beefy power supply. in my video, I used a few heavy transformer based power supplies configured to deliver between 30 and 50V. One of the transformer power supplies used was the 12V 10A beast shown in the picture, and this power supply was in series with another, smaller 12V 4A unregulated power supply, which was in series with yet another 24V 2A transformer. Under no load, I was achieving about 50V. However, under heavy load (peaks as high as 8A), the voltage would sag to 35V. and the smallest transformer would overheat, so I had to figure out how to make the circuit not draw so much current.

My solution was to only power the circuit 10% or so of the time. I did this by using a 555 timer to turn ON and OFF the power to the DS0026 very quickly. A small NPN transistor was connected on the HIGH side of the DS0026 so that the the 555 can directly control the voltage on the supply rail for the DS0026. To power the modulated circuit, you will need at least a 12V 4A power supply, but to achieve the same results as I did in my video, however you will need 50V 2A.


At voltages higher than 15V, however, you need to consider that you will either need to use separate power supplies with a common ground (it is OK to use a small 12V wall wart for this supply), or use some sort of voltage regulator or buck converter to step main supply voltage down to 12V. I learned the HARD way 4 minutes into the video that a 7812 is NOT suitable to regulate a 50V supply. Killing my one and only 7812, I ended up using a dodgy Zener Diode Shunt Regulator. This solution is not ideal, and certainly not the way I implemented it. Only use this method if you are desperate like I was at the time. Regardless if that is the solution you plan to use, take a look at the last picture for the schematic.

Step 3: Prototype the First Circuit on the Breadboard

Picture of Prototype the First Circuit on the Breadboard

There is not a lot to say here, Just build up the circuit on a breadboard, connect the power, and see if it works! If not, troubleshoot and see what is wrong.

I recommend to start working on the power supply section first, in my case, that's building up the Zener diode voltage regulator. Make sure that can deliver 12V or so, and at least 100mA. Using a wall adaptor for this instead is fine, just make sure you pay attention to polarity and that the negative of that supply is connected to the common for the entire circuit. Use a large filter capacitor of least 1000uF as well as some smaller film or ceramic capacitors for better filtering of higher frequency components.

Once you verify the power supply regulation part of the circuit is working, you can move on to building up the DS0026 section and testing it. Once you make it, you can test it by connecting a LED to one of the outputs of the DS0026 and ground (paying attention to the LED polarity) and connect the input of the same buffer to ground and Vcc. The LED should light up when the input is grounded.

Step 4: Optional: Now Add the 555 Interrupter Portion!

Picture of Optional: Now Add the 555 Interrupter Portion!

Now just modify the circuit by adding the transistor between the power rail for the DS0026 MOSFET inverted buffer driver and the 555 circuitry to drive that transistor. Simple enough, right? (make sure there are no filter capacitors across the DS0026 itself, that defeats the whole purpose of modulating power to it on and off, since the capacitor will just smooth that out. But do keep the capacitors on the power rails themselves.)

Step 5: Testing, Troubleshooting, and Pictures!!!

Picture of Testing, Troubleshooting, and Pictures!!!

The golden rule of troubleshooting electronics is Thou Shalt test voltages, according to Dave from the EEVblog! So make sure that the power supply's you are using are healthy and working as they should. Then make sure that the 12V output of the regulator or separate supply is also powering the circuit correctly. If you are using a regulated power supply, make sure you are not triggering some sort of short-circuit or overload protection. Many modern power supplies use foldback current limiting meaning that if the circuit pulls more than a certain amount of current for even a split second, the output voltage will drop to a tiny fraction of what it was before, and stop the functioning of this circuit.


Triple check all your connections are secure and good, and that you did not goof up anything. If you choose to use slightly different parts, make note of those assumptions and make sure they are not whats causing the problems by trying the parts that I used.


If you are using the 555 interrupted version of the circuit, make sure that the 555 is oscillating correctly. If you have an oscilloscope and a 10X probe, probe the output of the 555 while power is applied to just it, and make sure that it is in fact oscillating correctly. If you choose to use different parts for this, make sure that you are getting a square wave with a low duty cycle and about 10Hz-500Hz. If not, using a speaker connected to the output of the 555, you should hear some sharp annoying buzzing noise.

Try reversing the polarity of the primary coil, or the number of turns to see if that makes a difference. Again make sure connections are solid. I have spent over half a day collectively with simple mistakes like these. Even in my video I pointed out in an annotation that the polarity drawn in the picture is wrong! I did not have enough time left over to fix the mistake.


Make sure the tank capacitor is close to 500pF, do not assume that it is if you do not understand how to read values for capacitors. If the value is too low, the circuit will not work very well and will not give you spectacular results. Similarly if it is too high, then again the circuit will not work very well. There are some defining characteristics of the functioning of the circuit that you can really only learn by practice and building/messing with this circuit yourself.


If things are still not working, than it is likely you can killed some parts. I would recommend replacing the MOSFET(s), the DS0026, the NPN transistor, and the 555 with new ones, or testing the parts in question to see if they still work. You may find that the DS0026 and the 555 died, as I did at least 10 times in my development of this circuit. It is really easy to let out the magic smoke, but half the time when chips die, they do not show any physical signs of failure.


Hopefully by now your build is working, and you can achieve the same results as I have! All of the pictures are simply frames of the video, the last one having been modified by overlaying multiple frames to build up the spark density (so it looks more realistic) and reduce noise.


devin19177 (author)2017-03-02

Hi Max,
How do I make that thing musical? I wanted to play music or use a funktion generator app to tune the frequency but i have no clue how to do that :( can u pls help me with that?

thomas30 (author)devin191772017-09-06

Look at electroboom's videos

x81 (author)2017-08-17

What can i use instead of ds0026?? Can u give me some models please?

sandim15 (author)2017-05-16

followed your instructions to the letter and all that happened was the fist cap blew and there doesn't seem to be any power actually going to the coil could you tell me where i could have possibly went wrong?

-max- (author)sandim152017-05-16

What is your depth of knowledge with electricity and electronics? This circuit although it looks simple on paper, it is actually amazingly difficult to get it to work well without really understanding how it works, how to optimize it, etc. You might want to head over to youtube and brush up on some electronics tutorials. I myself have posted a couple totalling 30 minutes. Here is a short list of some things I feel would benefit you:

* voltage / current / power / resistance / energy / ohms law / watts law,

* complex impedance of capacitors and inductors

* the concept of resonant or natural frequency

* Parasitic properties of components and construction methods (like different coil designs and such)

That is a lot, I hope it does not discourage you.


"following my instructions to the letter" is actually not going to get you far with this very fiddly circuit. although that should honestly get you a working result. What assumptions did you make? Any substituted components? I need details to give you better advice.


I assume you blew a capacitor which occurs when it is overloaded (more current through it that it's ratining would allow) or overvolted (you exceeded the Working voltage or WV rating of the capacitor) or got the polarity backward (if it's an electrolytic: the shittiest type of capacitor)

sandim15 (author)2017-05-15

hi max what ca i use instead of a 555 transister?

-max- (author)sandim152017-05-15

Assuming that you are referring to the popular astable multivibrator configuration; Only if you:

a) Get one that can oscillate well into the hundreds or thousands of KHz, depending on the construction of the secondary coil and topload (CMOS variants are faster I believe, but you need to take care with the construction to avoid parasitic loading effects on the output of the 555 timer and buffer the output with additional BJT buffer drivers.)

b) Are willing to precisely tune it to the resonant frequency of the secondary (the oscillation frequency of the 555 as well as the resonant frequency of the LC tank circuit between the primary and capacitors directly in parallel with it. And It's hard enough to tune one thing manually.

~OR~ develop a custom 555 circuit that utilizes feedback to create a oscillator that can track the resonant frequency of the secondary LC system.

On_i0n (author)2016-07-28

Hi Max,

I use separate power supply to power the mosfet driver (I'm French and I haven't found the DS0026 for sale in Europe so I use a TC426). When I powered the mosfet driver on 12V the current in the ic was 10 to 20mA. After that I increased gradually the power in the circuit (mosfet+primary coil). At approximately 18V the current has increased to the limiting value of my power supply (3.1A) wisch has produced a strange humming. The current in my ic was at 310mA so I turned off the power supply. My mosfet (irfp460) is not dead, because it switches on when I touch the gate. Unfortunately, my TC426 is now constantly very hot (and I measured 200mA on vdd) so I think it burned but I don't know why (I use 1n4148 diodes but now I don't know if they work)... I still have another TC426 and an ICL7667 but I am afraid about burning them :/
My power supply is an ELC AL936N. Any suggestions?
thank you in advance :)

-max- (author)On_i0n2016-07-28

You can also alternatively try making your own MOSFET buffer driver with a couple of transistors. Use 2 (a NPN and PNP) transistors in the emitter follower configuration with the base's connected together and the emitters connected together. The emitters go to the MOSFET gate, and the base is fed from the feedback pin. Due to the nature of PNP and NPN transistors, protection diodes are not critically necessary, as the PN junctions will do the trick. The transistors are acting as emitter followers, so the NPN collector is connected to Vcc and the collector of the PNP is connected to ground.

MarkP26 made it! (author)-max-2017-03-17

Oh dude... Why didn't I think of that when I ran out of driver chips? Typically lazy me just jumped online, threw more drivers on the card, and waited for the mailman to bring me a present. Duhhhh. Funny you mention the 0026's being in your "antique parts bin" down below. I went through my last couple on this project as well, and when I went to order more they were discontinued at both Digi and Mouser. I did notice that Jameco had them in stock but there were lots of lower priced, more robust options at DigiKey or Mouser, so I went that route. I think I ended up using a MC34151? Anyway, I just thought your comment was funny... "Antique parts bin" . Love it!

Anyway, I just wanted to say thanks. This is a great project. I designed my small sstc using this project and your youtube tuts as inspiration, although I have to admit I used a combo of yours and electroboom's topload designs <see photo>. It's a pair of 2.5" drive platters (one over one under) and a hand wound 12ga bare copper coil bent 'round into a torrid of sorts. Honestly I think 2 3.5" drive platters worked just as well, I just think this looks cool. :-) Thanks again for the inspiration. Keep up the good work!

Ok, I'm off to breadboard a gate driver now. Oh, do you think the old standard 2222, and one of it's p-n counterparts (maybe a bc638?. I have some of them in the bin.) would work for this? I'm assuming they should, or am I missing something?

Note: Photo is prior to changing over to the Mosfet based driver. At this stage it was basically a standard slayer circuit using a TIP35C running at 30-ish volts. It actually worked really well for being a whimpy little single transistor design. It gave about 1/2" arcs and 3/4" plasma jets on the spinner.

On_i0n (author)-max-2016-07-29

The transistor driver is probably more robust, I'm going to make one, thanks ;)

-max- (author)On_i0n2016-07-28

It's hard to say, I killed all my DS0026's working with this circuit, too. And I have no plan to buy them. (I only used that chip because I had them in my antique junk bins.) Look up the datasheet and have a glance at the Absolute Maximum Ratings for your device, it will list all the things that, if you exceed, will result in the magic smoke.

MARMUTBOY (author)2017-03-11

Ow, ok thanks MAX ;D

MARMUTBOY (author)2017-03-11

for its power supply I used 5 ampere 15 v does not spoil everything ?? and whether they are efficient if I use the 5 ampere ??

-max- (author)MARMUTBOY2017-03-11

I think you might benifit from watching my 2 Tutorial Tuesday videos to get a better grasp on voltage and current.

In short, when you use a low impedance source (where the output voltage does not sag much with increasing current draw) then the load gets to decide the current draw.

The slayer exciter will draw more current when you apply more voltage to the input, and the power consumption increases substantally. You may find that your circuit attempts to draw greater than 5A, and your power supply may decrease the output voltage to almost nothing to protect itself. Depends on the supply.

pradumank1 (author)2017-02-03

Can I use 12 v ATX PSU to power this stuff up

PrimožS2 (author)2017-01-12

My MOSFETs get very hot in the first few seconds of running, so i just unplug the power supply. I'm using 2 paralleld IRFP450s. What should i do?

-max- (author)PrimožS22017-01-13

You should totally refer to my youtube tutorial and ask there! ;)



jk. Assuming you tried everything in the tutorial section (DO THIS PLEASE) then there is a good chance your MOSFETs are dead or your driver is dead. Build up a basic test circuits and troubleshoot each component. Silicon tends to fail easily, so diodes, transistors, chips, etc.

Plenty of tutorials of how to test transistors and MOSFETs, The DS0026 or equivalent chip should produce an inverted output on an osciloscope compared to the input. The output should be able to drive a load with static voltages present on the input.


You should have a read through this to understand why parallel MOSFETs is NOT a good idea if you don't know what you're doing.

Basically the gist is that because no 2 MOSFETs are identical, one will conduct way more current than the other when ON and especially in the linear region of operation. You need current sharing resistors on their drain and gate for reasons explained in that application note.


p.s. If you plan to do much more electronics you gotta learn to read up on this stuff! It can get intense, I know. Look into picking up a copy of the Art of Electronics. It has almost everything you would need to know in it!

rah187 (author)2017-01-11

Great project! Actually, I have attempted to do this project once before, but the problem was the power supply. I would like to avoid buying a commercial power supply, and would much rather build one myself. Can I just use a few large, salvaged transformers?

PlasmaGuy101 (author)2016-12-19

Could I use an FGH60N60SMD IGBT instead of the IRFP250N mosfet?

OrlandoZetaP (author)2016-10-01

What are the measures of the coil? and what is the thickness of the copper wire around it? I would also like to know what you used to the top. Thank you very much for the tutorial!

m4nb34rp19 (author)2016-06-26

Hey Max,

Finally getting round to this circuit - brute power supply it is! those other ones I've been messing with are fine for smaller normal circuits but the slayer circuit has let smoke out of four psu circuits now, interestingly, the old workhorse psu i originally used is still cruising along at 25VDC but i'm moving on. I built full bridge rectifier and will use that on the hi voltage side, only problem(?) is I have 73VDC at the output. I have IRF540N MOSFETs, do you think these will be ok? I think they're ok for 100V but not sure about the driver chip getting excess feedback voltage given that i have 73VDC feeding it. Should i increase the value of R3 or will that still be ok do you think?

Just re-watched your video of this thing, OMG the sound it makes when the interrupter is added to it is just awesome! Sounds like such a beast, I can't wait to get this going :)

-max- (author)m4nb34rp192016-06-26

Thanks! :)

No, IRFP540 MOSFETs are not close to good enough. :( This circuit will kill IRFP250N transistors at half that voltage. Consider picking up a few FDP33N25 MOSFETs, they are similarly spec'ed to the IRFP250N but half the cost at reputable electronic distributors like mouser or digikey (about $1.44 @ Mouser in 10's)

You have to remember when driving inductive loads like the primary of the tesla coil that you will get high voltage kickback that can be orders of magnitude greater than the supply voltage. My 24V flyback driver has up to 400V back EMF transient spikes on it without methods employed for snubbing.

Hopefully you don't plan on using a zener diode voltage regulator to take 70V down to 12V, cause that would be very VERY inefficient, and quite dumb, really. Might as well use an oven heating element for the resistor and zener diodes the size of bolts mounted on a car radiator for cooling, or you use a proper switching regulator. Any 12V wall adaptor would work.

I determined R3 experimentally, I do not know how it's value should change with respect to input voltage. Really when developing the circuit I found literally any value between 1 megaohm and 1k worked. I do not think it is that critical. It simply offers a slight bit of negative feedback which slightly reduces the gain I think.

m4nb34rp19 (author)-max-2016-06-26

Cool, I'll look into some of those, cheers for that. Will they handle 73VDC in your opinion? Are there any bigger or better ones you know of that would suit given the extra volts? If it means spending a little bit extra, and using extras in parallel so it doesn't go pop i'm thinking it's probably worth it, wife always gets upset with me when circuits explode or make flames on the kitchen bench, and there's been a couple lately :)

Yeah definitely wasn't planning on doing that, got a separate psu for the 12v side, I think is good for 2A, (not that it'll need that much but is nice little DC brick power pack so should be ok for the low side, wired it into my big power supply so is able to be one wall plug)

Do you think 73VDC is too much? The transformer is supposed to be 50V but i suspect its rating might be at 230V (and here it can be anywhere from 230VAC-250VAC at the wall and i have 250V at this place). I lived at place where it was 225V a few years back, just depends on the area. but i'm guessing (without doing the calculations) thats where the extra is coming from, the reason i bought that one was because it was big 3A or 6A if you use both outputs in parallel and 50V! (and on special) lol turns out I got a bonus model i guess haha :) now left wondering if it's too much.

I was gonna test the high voltage side on my trusty old 25VDC psu first before throwing the other one at it just in case anything goes wrong anyway just to be safe and to not blow it up :) so if all else fails i'll still be able to run it, just not at it's full potential

-max- (author)m4nb34rp192016-06-27

Let me guess: It is rated for a output of 50V AC, I can tell you that it is indeed very close to that, and is actually 51.6Vac, well within 5% tolerance. I will let you figure out why the rectified output is considerably higher. (hint: RMS vs peak voltage. Google that one.)

m4nb34rp19 (author)-max-2016-06-28

Ah of course, your hint takes me back to physics class (Root Mean Square), won't need google for that one (this time haha). RMS didn't even occur to me lol.

-max- (author)m4nb34rp192016-06-28

Yup! Although in reality in is not even exactly sqrt(2) higher because that assumes perfect diodes, no ripple, and a perfectly sinusoidal AC power (not modified AC). A single rectifier diode can drop anywhere from 0.4V to 1V depending on the current through it (sometimes modeled as a fixed voltage drop of exactly 0.65V regardless of current, which is close but not quite.) So if you use a full bridge rectifier, then There are 2 of those diode drop voltages because in each cycle after rectification the current has to flow through 2 diodes. You can trace out how the current flows pretty easily to see this yourself.

Now if you really want to make this circuit efficient, you can try to set up the LC tank circuit at close to the resonant frequency of the circuit to achieve class E operation! It is not easy and requires an osciloscope for tuning, but it is possible. Try to get the transistor gate to go high exactly when the instantaneous voltage due to the ringing oscillation gets very close to 0V, this will allow ZVS switching or soft switching. Because the MOSFET switches when there is no voltage across it, it is very efficient. This is simalar to how the ZVS flyback driver works, which relies on a royer oscilator to acheive the same soft switching in each MOSFET.

-max- (author)m4nb34rp192016-06-27

I would consider using something like a variac and slowly cranking up the voltage to that level to see if it would work, but variacs are not the cheapest. (they are wonderful things to have around, however.) I used a maximum of 50V on my circuit and I rarely ever did pop IRFP250's. So I recommend you use a better transistor for higher voltages, like the IRFP460. But with bigger MOSFETs usually comes higher gate charge / gate capacitance making the gate drive circuit more difficult. Check out this site, this guy clearly knows his stuff!:

m4nb34rp19 (author)-max-2016-06-27

I was thinking these look pretty good IPW90R1K2C3 but not sure, is pretty cheap and is rated at 900V with same resistance as the FDP33N25 was thinking could parallel a couple of them perhaps?

-max- (author)m4nb34rp192016-06-27

Actually that one has a resistance of almost an ohm, 0.91 ohms. The FDP33N25 has a rating of 91 milliohms, or 0.091 ohms, an order of magnitude better. You can see that the one you posted is only rated up to 5.1A due to that (very high) on state resistance. You will find that it there are compromises between all the ratings of the MOSFETs, including on state resistance vs Vds vs gate charge vs price. It is not easy to find a good one, and good ones are not cheap.

m4nb34rp19 (author)-max-2016-06-27

Oh, so it is! My mistake, I thought the FDP33N25 had 0.91ohms, cheers for that i was way off! Thought the price was too good to be what i was after! lol :)

So, I kept looking and found these which more closely match the specs of the FDP33N25 (other than the price, which is why i'll get some FDP33N25s aswell i think)

STP34NM60N and STW34NM60N

I think those are pretty close, you're not wrong about the price going up to get ones that tick all the boxes! (all the boxes i knew to look for anyway) do you think either of those would do the job with around 70V?

Thankyou for your advice so far, it's much appreciated - I'd have a bunch of popped mosfets now and a bunch of money up in magic smoke without it!

Reposted this with correct links

m4nb34rp19 (author)m4nb34rp192016-06-27

Something is making both tlinks the same, not sure whats going on there. here's the correct link to STP34NM60N

Sorry about that!

-max- (author)m4nb34rp192016-06-27

Still the same transistor, just in a different package style: smaller TO-220 vs larger TO-247. TO220 is easier to deal with IMHO, but TO247 generally has better thermal specs.

m4nb34rp19 (author)-max-2016-06-27

Cool thanks for that, so do you reckon either of those two would do the job? I certainly won't hold you to it mate, just with you're experience and knowledge, you're opinion matters in the choice i make (you've already steered me away from some bad choices!) and hopefully when i get it working these posts will help someone else get some home-made lightning happening, and of course i'll post some pics :)

I also just found this one, which is a few bucks cheaper and looks similar in spec IPP60R099C6 is TO-220 but still looks like the specs are good (to me anyway) would no doubt need big heatsink and fan, probably run two in parallel of whatever i use too (I may purchase some of each if you reckon they look ok, in case i get some go bang - I'm under no illusion of this being straight forward so i won't be getting upset if they do, hopefully learn something so is all good)

Again, thankyou for your help!

m4nb34rp19 (author)2016-06-27

mistakes in link - reposted

-max- (author)2016-06-27

Mouser has that transistor for half the cost, however you do have to pay like $7 for the shipping, so I guess it does not save much unless you buy about 10 or 100. Mouser and digikey also have much larger selections, and a "paramaterized search" which allows you to select what ratings you need and all the MOSFETs that fit those ratings will appear!!! Then just list them based on price and vollia! That's how I discovered the 33N25! (Also generally speaking the first couple or so letters in front of the part number indicates what manufacturer made the device. LM is texas instruments,LT is Linear Technology,ST is STMicroelectronics, FT is Fairchild Semi, etc.)

Arush Bansal (author)2016-06-03

I couldn't find the DS0026 FET Driver for the circuit. Could you suggest some other equivalent FET Driver that would prpbably work for the circuit.

-max- (author)Arush Bansal2016-06-27

In the comments I have answered this question many times before, look for one of my replies showing how to use NPN and PNP transisors as a push pull totem pole circuit.

GabrielA55 (author)2015-11-08

Hey man. If I want to make a musical tesla coil with this SSTC ? How can I do it ? Can you help me ? Please .

-max- (author)GabrielA552015-11-08

Not really, since I have not made a musical one yet. However, electroBOOM from youtube has. His is almost as powerful as mine, and is capible of being musical.

pdutra (author)-max-2016-01-03

I can put an audio signal in the transistor base and use the coil as a musical coil instead of using the 555?

-max- (author)pdutra2016-01-03

you probably could, I thought about doing that myself. However audio fidelity will be at the sake of the MOSFET linearity. Also the MOSFET will be driven with a amplitude modulated signal if you do that. However, I'm sure you replace the 555 with a monophonic squarewave audio synth. That way you could do some basic MIDI playback.

FadyK (author)-max-2016-06-01

I tried it and it worked perfectly. my mosfet is also strangely cold, works a bit over ambient temps(with a heat sink).

I've used an arduino to provide musical tones to Q2(replaced with tip41c).

FadyK (author)GabrielA552016-06-01

ٍEasy way to make it musical, same schematic but instead of using a triple 5 modulator, you can put any musical source, speakers output with an amplifier would work fine.

I used an Arduino and loaded up some RTTL musical tones on it, then wired the output pin to the transistor (Q2). it worked like a charm.

m4nb34rp19 (author)2016-05-06

Just ordered those ICL7667's so i'll let you know soon if they're a good replacement for the ds0026 (well, as i don't have a ds0026 to compare with, i'll just let you know if it works well or not). Also caved in after my third cooked power board, don't know whats causing it and i don't care anymore, ordered a 50VDC 3A power supply board kit to run off my transformer so i have some adjustment for the voltage. Depending on postage times, should have some pics soon!! I'll make sure my old psu is ok while i wait so i may test this with 25V if i'm still waiting, should get the ICL7667's before the rest of it so at least i can build this while i wait. Delays man, driving me crazy! i'll probably try get the 555 section bread boarded and running this weekend. at least i have a few of them spare if i cook them :)

-max- (author)m4nb34rp192016-05-06

Yeah, a suitable power supply is important, and that is why I mentioned that a many less beefy switchmode power supplies are generally either too electrically fragile or too "smart" for their own good. I was able to get away with powering this circuit without problems with what is proving to be a very rugged 24V/4A --- 48V/2A switching power supply. It seems to be a sort of hit or miss deal with them. I used an xBox power supply (12V 12A) for my flyback driver circuit, and it was too smart for it's own good. Luckily it was not hard to hack it to disable all safety short circuit protection features. For obvious reasons I do not recommend that however.


If you are ordering a kit, I should point out that linear regulators, while comparatively simple to design and build, can be very inefficient when the difference between input and output voltage is large.


One further idea with this kit might be to use a fluorescent ballast and power the circuit directly off of AC mains. This would be a bit dangerous, and changes to the design of this circuit would be required. But it would be comparatively cheap to having to get an obscure power supply. I may attempt to redesign my circuit again and see if I can get it to be both more efficient and get it to safely and reliably run off of >50V. One immediate improvement necessary would be to use better suited MOSFETs. The IRFP250 is old and almost completely obsolete, and there are better MOSFETs on the market that have lower on state resistance and lower parasitic capacitances, which leads to faster switching times and lower power losses. However I am still researching which one would give the best compromise between all these factors and price. If I had a variac, I could wind the voltage up and up slowly and continuously to precisely determine what the breaking point is.

m4nb34rp19 (author)-max-2016-05-08

I have so many MOSFETs i could no doubt scavenge but i'll probably just buy some new ones so i know they're ok. any in particular you think may be worth a look at? (Is no big deal if i try one and it isn't suitable, i won't be blaming you! that's all part of the fun is seeing what works and sometimes what doesn't and how it changes things)

Interesting idea about the flouro balast, sounds like i'd wanna do my homework first though but that could also be an option if the psu saga continues after i get this kit (I'd already ordered it before i posted about it so I'll just cross my fingers lol), at least i'll be able to do other stuff with it if is no good for the coil so is all good :) but i'll still need some thing so yeah the flouro ballast is something i'll look into, that sounds like a good idea (after some reading of course, don't want to get zapped!)

-max- (author)m4nb34rp192016-05-06

Sounds good! When it comes to power supplies, it is kinda hit or miss, and hard to predict which ones will do the job, and which one's won't. For my flyback driver, I choose a xBox power supply because it is capable of delivering 12V and 12A. However I kept tripping the overcurrent/short circuit protection in it, so I had to hack the power supply and install a mod wire from an optocoupler directly to the 5V power rail through a resistor to ensure the safety chip inside could not function properly. For obvious reasons I do not recommend that. For this circuit, I picked up a 48V 2A switching power supply that seems to handle it fine. (this power supply does not have "foldback" current limiting, just normal current limiting.) I have not measured if the supply actually delivers the full 48V to it or not, however.


Since you ordered a power supply kit,I hope you did not choose a linear regulator based one. Linear regulators are very inefficient when the difference between input and output voltage is large, and they would need substantial cooling.


Also, IDK if you care, but over this summer, there is a (small) chance I *might* actually go commercial with my projects and sell kits that I put together. I will work to improve all the circuits to the best of my abilities, and sell all the parts and a printed PCB, documentation necessary for anyone to be able to build things that work possibly even better than in my videos! Currently I am redesigning my flyback singing arc plasma speaker as the first kit, and since my older SSTC videos are also really popular, I may be a second kit as well.

m4nb34rp19 (author)-max-2016-05-08

Cool, hell yeah i care! That would be pretty sweet, pencil me in for one when (if?) you do, I like building from scratch but isnt always ideal. If i could make a request to have places on the board that you can use some little pcb screw terminals for the bits that can go pop so is easily replaceable? i did this for the resistor and diode on my slayer circuit and was handy to either replace or experiment with different values. I should probably do it for the transistors too but something feels so dodgy about that :).

I have a feeling it is a linear psu, but cooling shouldn't be a problem, i got old gaming rig sitting there with water cooling which i'll scavenge if need be, is going in an old aluminium mini pc tower, if you could call it a tower, more like a large shoebox! but i'm putting heaps of fans in this too and big heat sinks so hopefully its all good, if not - water cooling, but hopefully not but if that doesn't work then brute psu it is! heres a link to the kit. If it works ok i'll let you know in case anyone else decides to go that path. I think my transformer is around 6A with 2x50VAC pairs which can be either parallel or series or two separate circuits which i like the idea of. Is why i ordered two kits, i hope they work haha! if not i'm sure i'll find another use for them. so is all good. but the inverter driver chips are on their way finally so i'll at least have 25VDC to play with when they arrive in the mean time, should at least be enough to test with.

I got some transistors for the totem pole emitter but i just haven't had time to fiddle with them yet, i'll probably get the driver chips before i get a chance to do anything with them :)

PoyrazR (author)2016-04-27

is totem pole work same with the ds0026? and when ım using totem pole ı must to change something incircuit or all things are same? (sorry for my bad engladn :P)

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More by -max-:Easy SSTC, Slayer Exciter On Steroids!How Electricity & Electronics Work: All you need to know guide to getting started(This instructable is dead.) Singing Arc Plasma Speaker project - revision 2.0!
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