Picture of How To Build A Simple But Powerful Flyback Driver
Tired of little purple sparks? Want bigger hotter sparks? Then try: 

The ZVS Flyback Driver

It is probably the most powerful and efficient flyback transformer driver that was fairly recently invented by Vladmiro Mazilli. It uses resonant zero voltage switching (also know as ZVS) to drive the flyback transformer. This means the MOSFET's are designed to switch (on or off) when the voltage across them becomes zero.

Because the MOSFET's switches when there is no voltage across them, it will generate very little heat, the only source of heat is caused by the MOSFET's internal resistance. Unlike the simple 555 timer flyback drivers, The ZVS flyback drivers will allow you to run your flyback transformers for much longer periods of time before the MOSFET's overheat. If you get really good MOSFET's, it might be even possible to run your ZVS flyback driver infinitely! (Or until the circuit is interrupted)

Video of it working! 

Step 1: The dangers of the ZVS flyback drivers

Picture of The dangers of the ZVS flyback drivers
Not only the ZVS flyback driver is powerful, but it is very dangerous. You can easily pump several hundreds of watts into the flyback transformer and the output current would be around 50mA to 200mA (or even more), which is way above the lethal rate which is 10mA.

Do NOT attempt to do this as your first flyback transformer driver project, I recommend you to start with using simple 555 timer flyback drivers before thinking about building an ZVS driver.

And finally, you are solely responsible for any harm to others or damage or any other problems that a ZVS driver may cause. The ZVS driver should be used for educational and research purpose only.

That is the end of my health and safety rant. :-)
AhmadM112 months ago

Finally I made it!

But something just feels not right.. The stream from flyback transformer always try to breach anything to find ground.. And mostly it did it in one way or another, every time I move the cathode away.. Once the stream lost, it's like going wild.. Sometimes I can see sparks outside the fuse case of the DC PSU..

I drive it from a 10A 36VDC PSU.. I doubled the 2W resistors value and increase the zener to 24V also two 270nf/400V caps in parallel as the final caps..

I've been questioning what could be wrong with the circuit.. Or is it just because the voltage too high for my entire circuit/case design? Because it still can reach my hand through my 50cm PVC chicken-stick.. I can feel it and I can clearly see a slight stream strike back to the PVC.. Kinda strange for me because a PVC should be a good insulator..

IC5 AhmadM1127 days ago

At high voltages dielectric breakdown occurs where electrons find their way across an insulator due to ionization. PVC dielectric breakdown voltage is around 40 Mv/m. If your design is definitive, you could also seal the entire thing with wax or submerge it in mineral oil

AhmadM11 IC57 days ago

OK.. Problem solved.. My chicken stick is a grey PVC pipe that made of pipe contains grey dye.. Even in a small measure, it's still more conductive compared to a white PVC pipe which contains no dye. It has been proven.

Anyway, the wax that seals the flyback still can't resist the spark leap from the HV pin. I want to choose the mineral oil, but the overall size would be too large. I just leave it as is until I find another solution..

And thank you very much for your advice..

move the power supply away from the driver and the driver away from the transformer (increase the length of the wires) that would work also try using insulating tape on your chicken stick.

For some reason I get both DC and Ac at the output also DC and AC in the input and I tried using a toroidal transformer since I didn't have any flyback transformers and it just heats up and the circuit only takes in 6 volts 5 amps even though my supply can give 20 volts 12.5 amps.

I had the same issue;

I found putting a nice big capacitor in paralell with the power supply did the trick, i'm pretty sure the issue is a large voltage drop when you initially power the circuit, preventing the FET's from being switched properly, the capacitor provides a little stability at the start, as the capacitor resists the rapid change in voltage.

Hope this helps

Alternatively use a more stable powersupply such as a computer PSU

My toroidal transformer just heats up and no voltage/current is registered at the output.

chiranth23 days ago

wat is the frequency of the out put? is there a way of increasing or decreasing the frequency of this circuit output?

_Totoro_ made it!1 year ago

Great driver and 'ible! barely gets warm at 12v coming out of a PC PSU and really nice arcs, modifying a Microwave Transformer soon for 24v for longer arcs. Fiddling with the capacitor value helps a lot to get the best out of your flyback. I ended up with an arrangement of 6 caps (1µf 275v), 3 pairs in parallel then those 3 pairs in series to achieve 0.66µf capacitance that has a rating of 825v which meant less capacitor heat and easier to modify the frequency with different arrangements, this the is the calculator i used for the capacitor arrangements http://kaizerpowerelectronics.dk/calculators/mmc-calculator/


How does your PC PSU not have current protection?

bypass the optocoupler, simply solder a diode in the optotransistor side (the input side).

Optotransistor? Also, my driver outputs 20 volts AC between the centre wire and surrounding wire at the end of the circuit but when I connect the flyback transformer primary coils, it registers as 0 voltage on the output and 6 volts AC on the input. This is when i bought a power supply that provides 12 volts, 12.5 amps.

It's relatively easy. Computer PSU internal circuit usually divided into two section, input and output. The optocoupler is the bridge between them. Just solder the two optocoupler's pins inside the input section together and you'll get full power written on the PSU case (give or take 10%).


Thanks :D


BenderSanchez2 months ago

What is the voltage of this thing roughly?

Vp=Pi*Vin or 3.14*12=37.68Vp


mkjunior2 years ago

built this circuit and when i first plugged in a 9v battery, i could hear the high pitch from the flyback.. consequently though I didnt see any arcs and the high pitch tone changed when i tried touching the ground output from the flyback to the positive output. Randomly though the circuit suddenly worked and i saw some nice arcs, but a bit later the circuit was doing the same thing as before. does someone know whats happening?
you don't have enough current from a 9v to turn the driver on, you need at least 10 Ampere to satisfy the driver. hope this helps.

PSU power supplies should do the trick but modfiying them to shut of current protection is a pain.

Dude, that's easy, just look at the optocoupler, solder a diode in parallel with the output of the optocoupler and voilá, no more current limits.

Try a rechargeable drill battery, if tou don't want to buy lead acids
TK1756721 year ago

Thinking of building this and i wanted to use a computer PSU but i wanted to ask: if i just connect it won't it try to draw the map amps the PSU can give and and possible damage the PSU or will it be fine? would i have to limit it in some way?

I tried using a PSU, it provides approximately the current required but I think there is something wrong with my circuit.

Nope current limiting is the problem, the PSU shuts down when too much current is drawn from it.

I was fortunate to get an X-box power supply that was fried. blown trace on the input and some blown caps and some soda residue... fixed it up. 17A at 12v (can be pushed to over 25A before overcurrent blows but it starts to warm up. upgraded to copper heat sinks and better fan.) makes a nice ham radio power supply. (20 or so amp at less than %50 duty cycle.)

for flyback driving i get the best arc at 1+1 turn :P need to mess with induction heating.

mcrenno219 months ago
Do the math to find your output voltage,
Output amps= .02-.7 amps
1:135 flyback ratio base on internal winding
turns 5+5 turns
input voltage ??? Depends on you,
my zvs
input 28v
output 63000v
I2 26mA
turns 6+6
20141110_190028.mp4(240x320) 10 KB

What did you use to power it?

For some reason, my PSU triggers the short circuit protection when I connect it to the circuit, how do i disable that?

shigeno213 months ago

is it possible for a hog stunner? how could i increase the current ?

Why would you want to stun a hog.....

it is my project for a backyard slaughter house i think a minimum amp to stun a hog is 1.25 amp can i use a microwave transformer rather than a flyback transformer of tv? can you help me thanks in advance.

1.25 amps, how many volts, what is the power in watts?

hmm around 220-250V so i think it will have a 275-320W from a minimum of 1.25A

Mains current unless you are hunting then lithium batteries connected to an inverter, this is hundreds of thousands of volts.

dillonxti11 months ago
I need a version where you don't need zener diodes and you can use the wall voltage to power it
I meant I may need a version where you don't need zener diodes and you can power it straight from the wall voltage

Dude,i''ll give you a hint, if you just want to power up your flyback you can modify a power supply, just fking remove the original transformer, find the primary winding using a multimeter, and weld the old pcb to your transformer. Weld a simple diode (IN4007 or other) in parallel with the output of the optocoupler to assure that the driver will work in maximum charge, and voilá.

It took me 20 minutes to weld the whole thing and make the new turns on the primary of the flyback. **i used 100 turns.

I actually made it work without the diodes and transformer my autospell kept putting need instead of made so yeah it did that to me twice

Could you send us a schematic?

the circuit on the left is my schematic the one on the right is the original -video of it driving a Tesla coil: https://youtu.be/s_HP_is5m_E

Thanks, got the instructable circuit to work though, the flyback transformer is

BenderSanchez2 months ago

Nice instruct able but I am facing some issues, my mosfets and inductor just heat up and it does nothing else, is there something wrong with the circuit or the mosfets or the inductor or the flyback transformer? Any valid help would be of great use :D

My flyback transformer is spoilt, its still outputing 18-19 volts AC

Yeah that was the only problem.

ybaggi10 months ago

Very cool.

do these arcs and sparks have any useful domestic or industrial application?

or is this all just for fun?

Making ozone

And what is Ozon good or useful for?

Disinfecting fruits/vegetables, but you have to dissolve it in water first, its also a strong oxidising agent but it is a free radical so try not to breathe it in too much.

z0tx4 years ago
I'm trying to build one of these, and this tutorial is excellent, I have one question: Will a couple of batteries in series be suitable for the power supply?

Yeah he used it himself

AhmadM113 months ago

Is this crcuit can be used as a power supply for electrolysis? Regarding the "visible" amperage that seen in the process when it melts a metal..

Actually I've made a circuit similar to this driver with couple adjustments like 3 turns(not five) in the feedback coil and dual parallel common 274J-400V-MPP as the final capacitor (Pardon my english)

fatevian2 years ago
Hi everybody!
Someone can clear me a doubt?
It works if I put a HV diode to rectify? Do you think it's possible with this circuit, to supply high voltage to magnetron oven? What do you think?The current is strong enough to break down the barrier of diode?Thanks.
I doubt it. The voltage is too high and current is too low. MOTs output much more current than this. Also, most microwaves are around 1000 watts, and this ZVS only has 400 watt input.
a good zvs can resonate a good thousand or two amps at 300 volts well at least that is what mine did with wall voltage
danmellow1 year ago

osum stuff mate... nailed it

i found my Fathers old TV repair stuff in the shop the other day, and i've found several caps that are in there that are in there that are around 40+/- Mfd

dudes1 year ago
get the irfp250's from taydaelectronics.com. they are only $1:50 each. and very low shipping
dudes1 year ago
any idea on the voltage that this puts out? after the flyback.

Can somebody explain me what comes out of that 3 terminals? (where the coils are attached). How much current or voltage? what kind of wave? why two different coils are needed?

is there a way to make it not lethal

Some common safety rules/procedures I have read are: Keep one hand in your pocket whenever the device is powered on. Always wear safety glasses. Place the device as far from the edge of your bench as you can and still handle it (In case it slips off the edge when powered up.) Keep an extinguisher rated for electrical fires nearby. Do NOT place the circuit anywhere near metal flashing or framing, etc. Put it on a dry insulating surface. Put yourself on similar material (Eg. rubber mat, plywood sheet.)

When possible use opto-isolators to connect low-voltage signal lines to the rest of circuitry, esp. when you are touching the low voltage controls. Separate the high and low voltage circuit components with a grounded metal cage or barrier of some sort. Obviously, the cage has to be large enough so that it's walls are not going to short out to the HV inside it. For HV outputs use wire rated for twice the voltage you are delivering with it. (All capacitors should be rated similarly; they can explode dramatically.) Take into consideration the current rating for the gauge wire you are using; you don't want the wire to melt or catch fire. Don't use cheap auto ignition wire for this purpose. Use genuine HV wire that has thick insulation. Silicone insulation should be more flexible than PVC. If you must handle the HV wires, use with rods of wood, rubber, plastic etc. Don't trust ordinary screwdrivers and pliers, no matter how much rubber coating is used on the handles. Use common sense. With these requirements in mind check everything twice before powering up.

I make no promises that this list is complete. Use common sense.

turn it off ?

Wow I just checked this comment and it was a long time ago. Even if it is lethal I am still going to build it as long as I have the time, money, IRFP250 MOSFET's and the inductor.
dillonxti1 year ago

I made something similar to this schematic

vknezevic1 year ago

I have wondered how to plug in rectified 220V without burning out gates of mosfet. Then I found solution, wich is described on http://www.joretronik.de/Oszillatoren/Oszillatoren...

somewhere on middle of page. People complaining that can't use more than 70v, and with solution on upper page cann be used any voltage

dillonxti1 year ago

use these Infineon 17n80c3

hohenheime1 year ago
How can I tweak the circuit to avoid putting too much amps on the MOSFETs, I couldn't find better than irfp450 (14A)
I don't mean to be jumping your case, but I must advise all people who try this schematic. Any of you recall the color code provided for a 10k ohm resistor? It is listed as orange/brown/black. This is not a 10k ohm color code, as I checked it on a calculator, and looked at the color/digit significance. This color code would actually be for a 31 ohm resistor. DO NOT USE this resistor if you are seeking a 10k ohm.

The actual color code for 10k ohms is of the same colors, but it is actually supposed to be in the order of BROWN/BLACK/ORANGE!

Thankfully, I recognized this prior to taking out the resistors needed from a TV motherboard. Do not worry about the 470 ohm color code provided, as the publisher has it listed correctly.

You're welcome.

MadDoctor Whitson
I recall how you were wanting to know why the negative terminal gets hotter than the positive when arcing. I don't know if anyone has answered this for you yet, but I will provide my input according to my comprehension of current direction.

First, you must understand that all the electrons come from the negative terminal of the circuit, and the high voltage positive terminal acts much like an electron vacuum. This is because all positive wires lack electrons, and when they come in contact with a negative, or ground wire, the electrons are sucked out from its resource.

Negative/Ground wires can't shock you, as the electrons can't flow into any conductor unless it lacks electrons - like a live wire.

Due to the negative/ground terminal possessing so many electrons, and the live terminal having virtually none, the terminal with the most electrons will get the hottest, as there is more electron friction in it. The live terminal doesn't get very hot, because any electrons to make their way into it are quickly "sucked" away, thus the live terminal still lacks electrons, and this lack in electrons results in very little friction.

Seemingly, everybody thinks the current flows from the live wire, when it is actually in reverse. It somewhat bothers me why schematics aren't designed in reverse as well. Due to this, I once drew a Tesla coil schematic in reverse.
Cormaxzyz1 year ago
What is the amp hour rating on the batteries you use to power this? Also do the batteries have to match (that is, same manufacturer and same ratings)? I'm asking because I've already burnt out a 5 amp hour battery with a few high-current experiments and I don't want to burn out any more!
Techno12132 years ago
Hello! I recently took apart a microwave and i didnt get a transformer, i got this. It came with no capacitor. How do i power it?
13, 1:55 PM.jpg13, 1:55 PM.jpg13, 1:55 PM.jpg13, 1:55 PM.jpg
This Is a flyback MOT. you can use the zvs on this kind
There is a transformer on there, it's the thing with the curved black piece going over the coil. You have to take it out.

This driver will not work for your transformer, it's not a flyback and isn't designed for high frequencies.

There are plenty of MOT tutorials out there.
jasshopper1 year ago
could i use irf460 instead of irf250?
astrikos2 years ago
this is a graph from the same circuit but now the 1microfarad MKP capacitor is replaced by a ceramic 10nanofarad trying to achieve higher frequencies

as you can see the half cycle is 1microsecond which means 500khz frequency

the problem now is that I do not get high voltage on the flyback

as far as I know the ferrite core goes up to 2MHz, may the problem be the capacitor which can not handle big currents so I will try a more powerfull capacitor

the diode may be another problem because it's not ultrafast

the FET is ok according to the datasheet for this frequency
XTL astrikos2 years ago
Its a resonant tank you are making with the coil inductance and capacitor. You are searching for the resonant frequency so just driving it faster doesn't mean it wil be more efficient. You need to balance the two out and drive it a frequency where the coil becomes resonant. Efficiency means the power will get through.
astrikos XTL2 years ago
I wanted to get high frequency and high voltage, not necessarily high power. I found out that this magnetic core works up to 160khz which is the frequency of the modern flybacks for big screens.
Mattef2 years ago
I think the reason why the negative terminal gets so hot, is that positive charged ions (Nitrogene+ and Oxygen+) are accelerated to it. The positive terminal gets bombed with electrons, but because they are less heavier, they don't generate much heat. Nitrogene and Oxygen are much heavier, so the "friction" (cross section) between the metal is even greater.
XTL2 years ago
The same driver can be used to heat any metal you put in the red wire loop (replacing the ferrite core flyback transformer). The cap value and number of turns (less) will need tuning to get the metal to heat up . The metal acts as a poor transformer core and resists the change in energy flow thereby disspating the wasted energy as heat. Generally a bad idea unless you want to heat metal up in an induction furnace.
XTL2 years ago
IRFP250 = 250V, 23Amps, RDS=140mOhm, Gatecharge(GC)=140nC
IRFP254 = 200V, 30Amps, RDS=85mOhm, GC=140nC
IRF540=100V, 33 Amps, RDS=44mOhm, GC=71nC
The 540 has a much lower voltage and might have had a problem switching, but its also likely the the Gatecharge (which is much lower) means you need a different tuned network. Try diff cap values.
arai102 years ago
Hey! thanks for this tutorial.i have almost completed the flyback circuit.But i don't have a suitable 15V,10A PSU.Can i get 15V,10A from the mains only by using a transformer ,bridge rectifier and smoothing capacitor,please suggest me the circuit.Your help would be highly appreciated.
Use a computer power supply. They have over current protection, short-circuit protection & various other things. they can be easy to come by. don't bother with transformers for your power supply... cause you need at least 10 amps for this circuit. I have yet to come across a wall transformer that's rated at 12V @ 10amps. PC power supplies easily have at least 20 amps... not to mention various voltages... ( +3.3, +5, +12, -12V )
qwertyboy5 years ago
You can get the MOSFET's from Digikey for $2 each. Doesn't sound like that much money.

You could also consider going to texas instruments for samples. Don't order a crazy load of them tho. I've ordered many samples from TI & they're awesome. Priority shipping. Best of all, it's free!
Plasmana (author)  qwertyboy5 years ago
If you are going to make them go pop a lot, then it can get pricey.. :)
LOL, yeah, just be careful not to let the magic smoke out
Plasmana (author)  qwertyboy5 years ago
Yes, it is hard not to.. :)
a2262633 years ago
How do I find which pins are the inputs to the primary coil on the flyback?
This site (http://lifters.online.fr/lifters/labhvps/tht.htm) says "With a simple ohmeter this is very simple, you will find easily the primary inputs because the coil resistance is about 1 ohm"

I bought a new flyback a couple of weeks ago. My flyback has 10 pins. I got these results:

Pins ..... Resistance
1 + 5 .... 2 ohms
1 + 9 .... 1.8 ohms
5 + 9 .... 0.9 ohms

2 + 8 .... 0.9 ohms

3 + 4 .... 0.8 ohms
3 + 6 .... 0.8 ohms
4 + 6 .... 0.6 ohms
All the other combinations (i.e; pins 1 + 3) produced no resistance, so that means that pins 1 + 3 are not connected. Conversely, this means that pins 1+5+9 are connected; pins 2+8 are connected; pins 3+4+6 are connected; and pin 7 and pin 10 are not connected to any other pins.

The first problem is that many of these gave me a resistance close to 1 ohm, so I still don't know which pins to use for the primary coil.
The second problem is that a flyback should have two sets of connected pins; pins that connect to the primary coil, and pins the connect to the secondary coil. However, I seem to have 3 sets of connected pins (or five sets, depending on how you count). Does this mean something is disconnected inside my flyback?

I didn't know what to do, so I just went ahead and connected it to the CFL circuit. I tried pins 5+9, 2+8, and 3+4 as the pins to the primary coil, along with every combination of the 4 pins on the CFL circuit, but did not get a single arc for any of them. Does this mean that my brand-new flyback is bad?
I had the same issue... IMO. don't bother with the flyback primaries. Just wind your own primary coils onto the ferrite core. once you have your ZVS circuit build & connected to your newly wound primaries, very carefully sweep your HV lead by all the other pins... you'll know when you found the pin for the secondary. You'll see a nice stream of HV. I like to solder a wire onto the secondary pin & do what ever then... Just be sure you discharge the coils!! being zapped by HV isn't fun lmao
build an easy circuit, such as mine http://www.youtube.com/watch?v=-rSm4IHb01s&feature=plcp and find the pins by arcing.
aadz932 years ago
Hey I have some stw88n65m5 mosfets which are rated at 650v at 84 A max will these work?
Lol yes, those are more then enough, as long as they are mounted on a heat sink & are N-channel fets as the schematic calls for, it will work lol. I had used many different kinds of fets before. The worst that will happen, is they'll pop into smoke... ( witch in that case, you'd better have a fuse, or a PC power supply. or you're asking for an electrical fire lmao )
Will these work? They're a dollar and eighty cents each!
astrikos2 years ago
A great caution to be taken.

When you start up the oscillator and before arching you should hear the 10khz sound.

If not then the oscillator has not started up and this means that on of the FETs is constantly ON and it will heat up to destruction within seconds.

This type of oscillator for some reason does not always starts up so you must stop the power supply immediately and start it again. This happens more often when you give low voltages, for example if you power it with 5 volts it's very difficult to get it oscillating but it is possible.

I managed to melt the case of the FET although I used heat sinks within seconds but the FET is OK.

I will device some method to be sure that the circuit will oscillate 100% if it is powered up.
astrikos2 years ago
this is the arching between the ground of the flyback and the high voltage output

the distance at which an arc can start-up strongly depends on the shape and the capacity of the electrodes

as you can see I have used two wood screws for not damaging the pins when they reach incadescence. between the tips of screws the arc starts nearly in contact only. between the bodies of the screws the arc starts at about 1cm.

I will use various other geometries as well as the Wimshurst machine electrodes which are spheres.

Conserning the sound you may hear when not arching, this happens beacause as you can see from the graphs the frequency reduces to one-fifth of the one when arching, which means that goes down to 10KHz, this frequency goes back to the power supply making the power supply to vibrate in this frequency which is an acoustic one.

I suggest that you don't run the ZVS without arching or anyway loading it some way.
a small correction, the 10KHz vibration and sound comes from the primary of the flyback, that is the two 5-turn coils and not from the power sypply, this is good beacause it means the choke toroid coil blocks the AC signal from going back to the voltage source.
astrikos2 years ago
yesterday I completed the permanent implementation of the Vladimir Mazili ZVS.

I attach two photos and two oscilloscope graphs of the two FETs. I used both channels of the oscilloscope, one for each drain of the FETs.

The low frequency and higher voltage graph is valid when there is no load/no arching on the flyback

When the flyback arches then the frequency increases and the voltage drops as you can see on the respective graph.

The destortion while the FETs go on and of may have to do with the diodes, I will try faster ones than the FR207.
astrikos2 years ago
yesterday I completed the permanent implementation of the Vladimir Mazili ZVS.

I attach two photos and two oscilloscope graphs of the two FETs. I used both channels of the oscilloscope, one for each drain of the FETs.

The low frequency and higher voltage graph is valid when there is no load/no arching on the flyback

When the flyback arches then the frequency increases and the voltage drops as you can see on the respective graph.

The destortion while the FETs go on and of may have to do with the diodes, I will try faster ones than the FR207.
astrikos2 years ago
As you can see on the graph, while the voltage goes down we have a distortion, this is probably due to not so good biasing of the FETs, that is the voltage divider of the two resistors needs optimisation, I will go on with tests measuring both FETs and changing the diodes to faster ones.

Even this "simple" circuit has a realm of parametres, practice is much more than theory

Just think that this circuit in theory does not oscillate!!!!
astrikos2 years ago
I will return with more photos, my camer ran out of batteries, and with more theoritical analysis.

My power source is an old AT computer supply from which I get the 12volts (yellow-black cables)

Certainly you should not run your oscillator without some kind of load on the flyback or without arching, the energy is stored in the circuit and I guess it will explode. The soynd that you can hear is some part of the circuit that oscillates in a frequency that you can hear.

I attach the image from the USB oscilloscope DSO-2090, this is the graph of the potential between the ground(source) and the drain of the one of the FETs.

As we can see the one FET is ON for about 10 microsecnods(100KHz) so a full cycle is 50KHz.

The voltage width of the oscillation is about 25 volts that is two times the source voltage.
astrikos2 years ago
this is the photograph
astrikos2 years ago
this is my implementation

it's 100% solder free

the flyback is a very old transformer and you can see the its box, I found at the local store for 2 euros

the whole project cost about 15 euros

the FET are IRF540N pin1 gate, pin2 drain, pin3 source

I didn't yet checked the frequency

the capacitor is MKP visaton 1microfarad
the fast diodes are FR207 alternatively you can use BY299 or the SF and HER series

FR207 switches in less than 500 nanoseconds according to the data sheet while UF4007 gives 75nanoseconds max. For our frequencies 500ns is ok

All these in Greece
I am bad at soldering and I put it together but I got no results. I made the inductor by winding 20 turns of 16 AWG magnet wire around a ferrite toroid and I made my own power supply by connecting the output of a 28 volt transformer to a 600 volt bridge rectifyer and the output to a 40 volt 34000 uF electrolytic capacitor. I tested the power supply and it works just fine. I am pretty sure that all of the components are connected but when i turn it on the transformer hums and one of the MOSFET's gets hot but when I try to draw arcs I get no arc. I did 5+5 turns on the flyback for the primary and it is not copper. Wheni turn on the the driver I get no sound except the 60 hertz him from the power supply transformer. Sorry don't have any images I did not take any but I can tell you I am really bad at soldering and that might be the problem or if MOSFET's are heat sensitive I may have cooked one soldering wires or heat shrinking it. Please respond soon I need help I Amos jealous of the people wo have awesome ZVS flyback drivers.
white.tiger2 years ago
its because the atoms at the negative terminal need to release some of its energy, in the form of heat, in order to allow some of its electron to jump to the positive terminal.
I got the IRFP250 MOSFET's and all the stuff except the power supply and the inductor which I will get later. But I have a question regarding the 0.68 uF capacitor my question is will a Mylar capacitor work because it is the only cap that I could get that was not an electrolytic capacitor.
iThinkBig2 years ago
would it be possible to use this as an ignition source for a pyro system?
What were the specs on the inductor
What value of inductor did you use. Also where can I get the IRFP250 MOSFET's

chen06762 years ago
hi everyone. I would like to know how much power is supplied to the primary 5+5 turns coil. is there anyway I could measure it ?
did you try a high power multimeter? I know someone who did it using this method
yes I run it up to 70 VDC @20Amp and not happen anything on ZVS my driver, but it makes flyback tv 29" burn out haha, nice instructables five star
put the flyback in oil and ground the negative pin. That should do it
Say I want to drive this at 100V, would two STY34NB50's work? and what other components would I need to change to accompany them?
will this mosfet work? http://html.alldatasheet.com/html-pdf/410677/JSMC/3DD1556-O-A-N-D/104/1/3DD1556-O-A-N-D.html it was right next to the flyback i pulled off on tv..... let meknow!
Hi i changed the look of the schematics can you say are the MOSFETS corectly in place ? Or maybe i forgot something. The small dits doesnt matter i will follow your and other information. Thanks in advance. Besides this instracteble was very helpful ;)
zvs - Copy.png
if no one has told you, your modified schematic is correct.
dalmond13 years ago
I made this today, works great, But I do have one problem, I have built many other flyback drivers, and they thing I find with this one is my flyback doesn't arc by it's self, it's more like a MOT in the fact that I have to create a Small arc before a bigger one will be produced upon opening up the sparkgap, what have I done wrong or is this the way it is ment to work ?

Cheers all for any input you provide :)
iTixle3 years ago
In the parts list you gave one of the items is 12 volt zener diodes. When you say 12 volt, is this referring to the breakdown voltage?
Higgs Boson3 years ago
Where did you get your flyback and what type is it exactly? Would a computer monitor flyback work, or a widely available models for newer CRT TVs? Which one's do you think work best?
rliu53 years ago
How do you tell what the voltage of the zener diode is ? I'm scraping everything to build this.
rliu53 years ago
How would a BUK455200A or a IRF640 work ? Took them both out of a computer monitor.
Jimmeh303 years ago
Is there a link to a schematic for this modification??
Jimmeh303 years ago
Virtip, has it right with regard to why the NEG terminal gets hot, the easiest way to wrap your head around (IMO) is to read up on tig welding.

The answer's regarding accelerated Ion flow are the more correct answers tho, given the HV field being generated.

Quick question tho, I built one of these with IRF450's, fired it up and got nothing. I now know that the input inductor I wound is FAR too large but, are you supposed to remove the air gap from the core of the flyback? or does it need the air gap to "fire"

grunff3 years ago
I built one of these, and it worked great for a few minutes at 24v, with nice 6-7cm arcs. Then both the IRFP250s failed catastrophically. Initially I thought perhaps the capacitor had gone open-circuit, causing the failure. But the capacitor is fine. Given that I was only running at 24v and ~8A, I'm puzzled as to why this happened. Any thoughts?
Darian s3 years ago
Could you use two different MOSFET's as long they have the correct specs
laserjocky3 years ago
I built and modified this circuit to get the most I could out of it. I'm using IRFP260s, I removed the zeners (any particular reason for those?), and I found that a 0.32uF cap works best for me (I tried many). I also found that placing a diode immediately before the (non-flyback) inductor increases the distance the initial spark can jump. The sparks aren't as long as when I hook the flyback to a simple square wave driver, but the spark is definitely hotter. When I simulate this circuit, it seems that once the circuit is operating, the current draw is very small, so I'm just curious how important it is to have a high current source. I'm using a 24V 0.8A ATX mod with decent results. It's almost non-functional at 12V 10A. How important are the high speed diodes? I'm using standard 1N4007s. Any suggestions for getting this thing working better?
Ok, I've got this thing working really well now. I determined that high speed diodes don't matter at all. There is no noticeable difference between switching diodes and standard 1N4007s at these speeds. I continue to have problems with huge current draw at startup, and I determined this is due to a lack of initial perturbations in the LC loop. The LC loop needs to have a pre-existing oscillation for the MOSFETS to drive a resonance. Shorting one of the MOSFET gates to ground briefly fixes the problem, but I need to determine a simple way of doing this automatically.

I will be making an Instructable of my modified design once I have everything nice and automatic, referencing this one of course.

what if you used a capacitor across the power supply that will hold whatever voltage
I just built a high capacitance mains rectifier circuit to go with my variac. It can handle about 8 amps continuously. I still don't have the right zeners, but as long as I don't go above 30V (maximum Vgs) it should be fine. After running it for about a minute, the copper plates I soldered onto the HV wires got so hot they desoldered. I'll be building a robust version of this soon, and I'll post my results. I'm still using the regular diodes, and still not sure if fast ones really make that much of a difference.
Aj963 years ago
How many turns, did you put on your transformer?
guruji13 years ago
I've built this with a 0.68uf cap. I would like to how much voltage and frequency is getting out? I'm using it on a 12v battery.
Any help please?
Inducktion4 years ago
Ehh. I built this, and for a power supply i tried using a bulky alarm system transformer. I rectified and filtered the power from the transformer, but its not working. The transformer is rated at 16 volts AC, at 26 VA, which i assume means 26 amps. When i plug it into the ZVS driver, the mosfets start to heat up, and the transformer heats up too, but nothing happens. I read the voltage going to the ZVS, and its only about 6 DC volts. I read the amps being drawn as well, and it starts at around 5.6, and slowly goes down, (not fast, slowwww).

When i dont have it plugged into the ZVS, the transformer puts out 27 volts DC. I don't get what the dealio is. I'm using a bridge rectifier and a 1500 uf 250 volt capacitor as the filter. And i know the driver works, because when i used several C and D cell batteries in series, the flyback starts working and makes tiny arcs. But when i use the transformer, the above happens, and the flyback doesnt even make any noise, at all.

Any advice, or problems with this? I even opened the transformer up, and all it is is just a vanilla transformer. Iron core. It heated up pretty quickly when i did plug it in.
26VA = 26 volt-amps (the AC equivalent of watts). A 16 volt 26VA transformer is rated at approx. 1.6 amps.

I'd either use a bigger transformer or a lead-acid battery (away from the circuit, you don't want your arc igniting battery gases). If using a battery such as that, put a fuse at the battery end of the leads as they can put out HUNDREDS of amps.
Unless my math is wrong, your not getting 26 amps, your getting 1.625 amps.
When dealing with electricity, guns, or high explosives, assuming can be dangerous. VA or Volt Amperage is the result of multilplying the amperage by the Voltage. Conversly to find amperage you simply divide the VA by the voltage to get amperage. If i am wrong I am sure it will be pointed out.
ahhhhhh. Okay. Thank you for that explanation sir. :D
Hm. Weird. I just recieved two lead acid batteries, 12 volts each, and i tried running it. Several of the traces on the board popped, and the wires get rather toasty, as well as the fets. The flyback still runs, but the sparks are rather minimal, very small. I've tried different inductors, that changes the performance alot sometimes. But, the question remains, why are my fets heating up so much, and why isnt my flyback running as well as it should be?

Do i need thicker lead wires?
you didnt hook up the batteries backwards did you? :P
also, try a 10 and 5 turn on the flyback instead of 5 and 5
26VA transformer means roughly 26Watts transformer... Which means that the amperage you can get from that is roughly 26w/16volt=2.16A... this kind of project needs almost 10A to be driven,so your transfrmer is definetly inadequate
aclark173 years ago
OK So I used 560 ohm resistors because thats all I have.. Not sure it would make this not work. But I spent forever putting it all together, and I hit the switch and nothing!!

However, my power supply makes a faint high frequency sound, and when I move the wires wrapped around the flyback core it changes the frequency. Also these wires get warm, almost hot, (not too hot), I suspect it may be working just fine, but my flyback is damaged from earlier experiments. Does this sound about right?

Im obviously getting the field effect going, but the flyback is just not responding. Perhaps I blew an internal diode? I have only one other flyback at the moment, but I thought I would ask anyway, in case someone has the same opinion :)
OK nevermind, I tested the flyback (duh) and it seems like its busted, Infinite resistance between the input pins when it should be reading about 0.8 ohms.

Tested my other flyback and got 0.8 ohms. I can confirm at least that the flyback driver circuit is working, however it doesnt seem much better than others I have built, but that could be because of the inductor (I switched to troubleshoot) or because of the windings on the flyback (theyre not wound 5+5, its an old setup) so when I correct these issues Ill try again, but this flyback is odd, it has a second smaller flyback (maybe a step down?) looking thing attached and it functions as the 0v pin, and theres about 8 pins on it. So Im also going to get another or several other flybacks and see whats up with that as well!
how much does it cost to build?????????????????????????
Well if youre getting your flybacks from TV sets, probably nothing. I found almost all the components for this from the same TV, flyback, capacitors of all varieties, many higher wattage resistors, they even have some transistors and mosfets, but youre better off buying those, I found them at the Tayda electronics website for $1.16 a piece.

All wires, inductors, and that stuff can also be found in the TV, as well as heatsinks for your FETs
i replaced each 470 ohm resitstor with two 270 ohm ones and it runs fine at 48 v

i found that most flybacks from CRT displays only last 5 - 10 min before failing
so i bought a DIODELESS flyback from amazing1.com , i used "PVM400" , i removed the stock primary and replaced it with the one described in the zvs plan and it worked perfectly , created 6-7 inch flaming arcs and nothing was overheating or complaining, and since it was diodeless it made lots of corona , a great alternative to traditional tesla coil

thanks plasmana for posting these plans :)
moris_zen3 years ago
At last I managed to get it going ... two issues
1. U cant connect a low rising PS (I connected it to a lab PS but the rise of voltage is too slow to get it started so had to switch in series)
2. I get sparks on the flyback internal legs many times until I manage to get the real HC on the output .. need to isolate them or something ...

I alos placed a very good heat sink on the two FETs with a fan but .. lol ... they don't heat up at all , even with fan off.
Any suggestions ?
nice circuit it worked great!
i just thought i might add that you can buy flybacks from www.amazing1.com
" FLYMIS" 3 miscellaneous FBT's $14.99
But more importantly they sell high quality, high power flybacks ( much more durable than the t.v ones) WITHOUT the hv output diode , so you can do more interesting stuff with them like power plasma displays

i just ordered "FLYPVM400" and will connect it to this circuit
other sizes and voltages are available

Umniscient3 years ago
Will the IRF510 work instead?
No. The D-S voltage and max current rating is too low on them. Use 200v and 15amp minimum MOSFET's.
jzhan3 years ago
How do the IRFP260N transistors fare?
Alex1M6 jzhan3 years ago
They work fine.
What is the model number of this flyback you are using? thanks!
solysol53 years ago
Hey I followed this tutorial but for some reason, mine cuts off after about 1 minute of operation. Any ideas? P.S. I'm running it from an old PSP-1000 Charger giving 5Volts at 2 Amps. Thanks
actually i use a 18v 5 amp laptop charger, use chargers for tvs and laptops and things they usually have some good wattage
shuhia solysol53 years ago
XD man you need at least 12 volt and 10amperage to run the Zvs. Tips, modify a microwave transformer or use your car battery charger !
R.A.T.M3 years ago
what is the poupus of feed back
skrubol3 years ago
Are you rectifying the output? As this is a transformer, it's output should be pure AC, therefore no positive or negative.
Normally on a DC arc the positive will get much hotter than the negative (at least 4x more heat I believe.) Plasma cutters always have the work piece at + polarity, and tig as well. Arc (Stic, SMAW) can run either way depending on what you're doing (whether you want to melt the base more, or add more filler,) and I believe Mig/wirefeed is usually workpiece - (electrode positive.)
shuhia3 years ago
Today, I managed to get my zvs working, with a washing machine capacitor: rated at

6uf , 360vac

I dont know what role the capacitor is playing but it works :)

I get super arcs with two irfp260 and if you guys can help me with rectifying I can run it with 41 amps...
shuhia3 years ago
I forgot to mention that im going to use a Toroid transformer, rated at 12vac 500va.

Any tips how to rectife it to dc since its a sine wave?
shuhia3 years ago
Is the capacitor optional? Becuase I they are expensive in Sweden!
shuhia3 years ago
Guys, I managed to get same arcs with a 555 timer circuit with pots. The only thing you need is to get 10 turns on the ferrite core with thick copper wire and a powerful car battery!
Alex1M6 shuhia3 years ago
What MOSFET did you use? All of my 555 drivers don't last long before either the MOSFET or 555 chip dies and I never got arcs like I do with my ZVS driver.

This is the type of arcs I get from my 555 drivers; BTW it is audio modulated.

shuhia Alex1M63 years ago
I use à Irfp260 mosfet, feeding it With 6 amps and 12v. The 555 timers circuit r1 is rated 10k and r2 1k. The arcs gives the worst sound you ever can imagine.
Alex1M6 shuhia3 years ago
Change R1 and R2 to 10K pots and you can then adjust it to an arc that is reasonably silent.
Does it matter which way I wrap the wire on the inductor?
doepy4 years ago
my theroy the ground gets so hot is that the hv is drawn towards it therfore the the heat goes with it
Alex1M6 doepy4 years ago
No, as electrons are negatively charged particles that travel from negative to positive. It actually gets hot becuase the positive ions are attracted to the negatively charged ground wire and bombard it, ions have much more physical mass than electrons which is why the HV electrode does not get (as) hot as the ground electrode.
Alex1M64 years ago
Hmm for some reason you have to be logged in to see embed videos, here is a link http://www.youtube.com/watch?v=2G6N2hvRx1w
Alex1M64 years ago
Great instructable! Here are my results;

knoxarama5 years ago
how would this work for a tesla coil power source?
here is my little one i made: http://www.youtube.com/watch?v=LUEPpR8uKIY
its run off a pretty much dead 12v battery...
It should work pretty well.
jhutton4 years ago
hey, so i did everything said here and i got about .5mm spark. so i decided to put 10 windings on the flyback ferrit core and 5 with the other. and it ended up working. so just if anyone has the same problem, thats all you gotta do.
jhutton4 years ago
if i use a power adaptor, what kind of amps range should i be aiming for?
very cool im getting a flyback soon
jj.inc4 years ago
So is winding your own coil around that core an alternative to finding the pins on the normal core. does it still output dc if you do this, and how does it effect efficiency compared to the original windings
Im not shure about ac dc but it you with lets say you "play" with 12v all the time and you try to find the best number of turns for the best arc then yes it is much better then trying and find the origunal coil because there are usualy 3 coils 1:hv 2:low v 3:not shure but i think that low v. and the low v 2 coil has pins for other number of windings. SO.... THE BEST WIND YOUR OWN !!!
Pyrofan4 years ago
how weak could you make one thats not lethal or is that not possible and how much would it be total? Thanks!
could i use a IRFP450.
somethings wrong, when i turned it on it made the high pitch sound like you said but none of the terminals gave me any results, i tested it with two different transformers and i believe the do work
its because it is a pulsing voltage and you meter wont read it unless you switch it to AC, even then it might not read it because it is too fast.
maybe the terminals are not close enough
or it cold be to close to ground
1august114 years ago
Ya that's not dangerous at all
You're right. It isn't. Neither is swimming in a child's pool, nor is walking down the street. Which is why safety precautions must be taken at all times and never operate without another person around. He/She's known as the "Shock Guardian"
nakarti4 years ago
After reading the multitude related links in Wikipedia, it seems the ion accelerator is the best explanation of the negative terminal heating up more, with the electron stream crossing the shortest path...
Another wicked or using modern jargon SICK! HV Circuit.

I made a terrible school boy error though--I was working off a schematic not a wiring diagram ---those FETS are robust or maybe I'm just Lucky..........
I could have cheated and used flying leads but I boarded it instead Boo Whoo......

I started with a 16VDC@12A power Supp and had 1" Fat Arc Ylw /Violet then put a Batt Charger 12Vdc@6A in series impressive 28V and an impressive Plasma wicked jacobbs Ladder :-o
Another wicked/ and using a modern word SICK! HV Circuit-

I did make a school boy error thought-wiring it from a schematic and not a wiring diag----those fets are robust or just maybe I'am lucky........?- I could have cheated by using flying leads but boarded it boo who! 1" arc at 16v-12A then I pluged 12v-6A batt charger in series --makes fast jacobbs ladder -----Saves trying to hunt for micro transformers to make plasma flames :-0

_BiG_4 years ago
Why get hotter the negative electrode? The answer is quite simple: when the air breaks down the molecules separate and produce free electrons and positive ions. These particles are accelerated by the high voltage field. The electrons run towards the positive pole and the ions run towards the negative pole. The ions are more than ten thousands heavier than electrons and can give much more energy to the electrode when impact. This energy is become heat.
ARJOON4 years ago
What will happen if i use a 10uf 400v~ mkp capacitor instead of the 0.68uf one.
virtip4 years ago
i cant give you an exact explenation as to why the negative electrode gets hotter than the positive, but i do have an example.
on a dc welder, the handle used to weld with is commonly made as the negative electrode, not becuase the welding handle gets hot, but becuase the handle stays cool and the positive electrode (the piece being welded) gets hot as hell,
the inverse is true when the polarity is switched.
and as to not doing this your first time, im going to go with this project for my first flyback driver becuase i think i have all of the necessary parts, except for the MOSFETs, i have two computer monitor boards (flybacks harvested), a large scanner power supply (circa 1980's), and the parts from two microwave ovens. think i may have found some MOSFETs in the scanner power supply, but im not an expert at identifying MOSFETs and searches on the part numbers on the cases turn up random pdf garbage that i have no hope of wading thru. help?
part numbers are:

Toshiba C5339 (monitor control boards)
Are you madd?
Very nice!
Am liking the vid - the bulb is particularly cool.

On a complete tangent, you have the same multimeter as me I notice - did you ever get it to read capacitance successfully? Reading capacitors with mine has never worked - it is either broken or I am doing something stupid?

Thanks for the ible. Any advice for using it to make an induction heater?
grenadier4 years ago

For those that don't understand the schematic: http://teravolt.org/ZVS_1.htm
Hey, i managed to make the ZVS driver, and i got some smallish sparks out of it...When i measured the ferrite core, on the day you weren't at BOCES though, it was something like 2.5 mH, not inbetween 47 uH or 200 uH. ...I reduced the turns, alot, and that helped a little, but do i need to maybe use a better power supply, other than that SMPS you gave me, which, by the way, clicks alot when i connect it up? (Like it's short circuiting or something).

I ordered two lead acid batterys from radioshack since I pocketed alot of money over christmas. 12 volts at 1.6 amp hours. Only 16 dollars each so i figured why not. :P
It clicks because you're drawing too many amps from it. It's a protected supply. The zvs needs currents in excess of like 10A.

You should've also gotten the batteries online.  1.6Ah will last all of 5 minutes. I suggest getting you $$ back and buying these.    http://cgi.ebay.com/UB1280-F2-12V-8Ah-APC-SUVS420-700R2BX120-DL700-Battery-/110595500805?pt=US_Batteries&hash=item19c0016b05
Is there a power supply i could actually make, specifically for the ZVS driver so i don't have to lug around big batteries, and can just use a smaller plug in the wall sort of thing?
Not really. You could use a modified microwave oven transformer but that's still heavy. I suppose you could get a 22v 8ah lipo pack. It'd only weigh a bout 2 pounds. They cost about $200 though.
Can i use batteries as my power supply?
It just depends on the voltage and amp hours of the batteries. But yeah you can.
Forgive me, for I am a noob in high-voltage electronics
But, what might this be used for?
The flyback driver is mostly just for fun, although it does have some smallish uses, like a high voltage power supply, or a Jacob's ladder.

Or you could go with another route and make it into an induction heater?
natsud14 years ago
hi first off im very new to electronics and dont know much about how things work i do know enough that i know when not to touch stuff like the HV stuff and how to be careful i tried to build this circuit (the original mazzilli schematic one) i couldnt find the irfp250 mosfet so i tried with irf540 ive went thru and quadrouple checked my circuit for mistakes but i cant get it to work ive noticed that when i turn on the touch my battery with the positive wire i get one ok spark but everything gets hot and no continous spark but if i rake my wire back and fourth on my battery terminal i can get several sparks . i looked up the datasheet for the irfp250 and it looks to me like it has a zener diode built in to it is that right? and the irf540 has a regular diode would this be the problem if so how could i get past this? so i gues my question is will the irf540 not work in this circuit im using just one 12v car battery sorry so long of message
www.digikey.com They have virtually every component known to man (or woman). You can request a free catalog by going here: http://dkc1.digikey.com/us/en/pdf/Current.html?WT.z_homepage_link=hp_CatalogButton There are options for downloading in PDF form, CD-ROM, and Mail Order-Please note this can take a bit to get to you, so be patient. I recommend the PDF version as it has searchable options.  But they do have two different options available.  (The mail catalog is HUGE, and unless you're like me and enjoy flipping through 2776 pages of components, it may be more difficult to navigate.

Another option would be to purchase directly from the web.  They have part specs.  Try googling "irfp250 purchase".

Hope this helps.  BTW, what are your plans for this flyback, if you don't mind me asking...
i just built it to see if i actually could build it i know it was simple but im new to electronics and im just building things that i think might be easy and neat i just used this as a jacobs ladder i actually dont know what else i could use it for thanks for the reply
There are many uses for a zvs/flyback! (Especially if the arcs look that powerful) You could hook it up to a resistor capacitor spark gap multiplier (I think it's marx multiplier) or make a tesla coil to name a few. try googling "high voltage projects" or something of the sort.
i googled it and i made it into an induction heater actually very simple change over just take off the flback and i made lika a 7 wrap coil of thickish wire soldered a wire in the approximat center of thecoil and rehooked it up just as if it were a flyback also added another capacitor after i tested it once cause one just gets to hot look what it did to this knife only took like a minute or so pretty fast i thought for such a simple project
Very nice, looks really hot, but the video is a bit lower quality, heh.
Just have to say again. Good job, man. I've been back to revisit the video to show fellow students and family members many times since I discovered it. Thank you for doing this project, and for posting the information so we can all learn from each other.
Very cool! Any thoughts on making this into an instructable? I would definitely like to give it a shot. Was going to build a Jacob's Ladder, but those seem so cliche. Any idea of the voltage output that would cause this powerful induction?
I just tried this, all you have to do is use high gauge wire in the same coil configuration, preferably pretty high gauge to account for the missing inductance of the flyback core, and put your work piece inside as in his video.
Nice job dude! I never though of using it that way!
i just found a thing called zvs induction heater would this be something i could use this for would i just take the hv out and attach copper to it and wrap a few turns the attach directly back to ground of the flyback? thanks
natsud1 natsud14 years ago
i got it to work finally at first the problem was that i had the tabs connected directly to my single heat sink but i didnt know that was the problem so i tried changeing my flyback windings what i di was i started in the center with two wires and wound outward in the same direction i thought that was what 5+5 turns meant which actually made the two windings backward from each other i think it would have been easier to understand if it said a 10 turns center tapped anyway and when i insulated my mosfets i didnt fix my windings back to where they were all in the same direction but i changed it and now it works and it works very well im useing 24 volts (two 12v "ups"batteries in series)and i get a starting arc of prolly 1 inch and pull it to around 3 inch this is much better than the 555 timer arcs i got whic were small and annoying sound the zvs arcs are nice white "flamey" looking and no whining sound comes form it also my mosfets dont even get warm at all thank you for going thru it step by step awesome i'ble
Hi there. I tried my ZVS driver that I made a couple of weeks ago now and I connected it up to a 12v SLA and I turned it on, but I got no arcs at all. I checked the direction of the windings, they were fine and the inductor and MOSFETs got warm, but still no output. Can someone PLEASE help me? Please? I'm so desperate to get this working...
dgcoffma4 years ago
thermionic emission
will this work with AC power
Plasmana (author)  Jimmy Proton5 years ago
AC power? Please elaborate
could i plug this into my wall (120VAC)
Plasmana (author)  Jimmy Proton5 years ago
They are other types flyback drivers that will run well off the mains. Here is one of the schematic (source) I found after searching on google.
so even if you do run it off the mains it still has to use DC you just need a Bridge rectifier
Yeah, a bridge rectifier and a smoothing capacitor would have to be used. Although, there is another half-bridge flyback driver that runs of mains, however the schematic is in Czechoslovakian, I think (LOL!). here's the link: http://www.danyk.wz.cz/igbt_2.html
i never even had any luck the the regular schematic, i find it complicated
You mean the ZVS?
yes, the only thing i used different was instead of a .68uF cap i used 0.48uF. it sounded like it was working...
"It sounded like it was working." What do you mean by that?
it made that high pitch noise.
And no arcs? If so, that probably means something is wrong with the winding connections...
maybe, i seem to have broken all of my cores, i tried gluing one back together with epoxy putty but i dont think it works, i also tried a a 555 circuit and that didn't work, WHAT DOES work it the 2n3055.
That is really weird. I definitely think you should replace your flyback transformer and treat the next one with more care. That should do it!
well i tried it with two and at the time they both worked
That is a very peculiar case... I'm terribly sorry but you might have to ask someone else. I hope I was helpful though lol!
well im probably going to make a PCB for it but thanks.
Actually he could run your design off of mains as well, but he'd have to include a transformer to lower the voltage. The scheme you've found uses some low voltage too (look for the +16V pin) to power the IC and drive the transistors.
p8ntball374 years ago
will this work well for the capacitor?
ARJOON4 years ago
my s3park3s are only 2 to 3cm long us3ing the 555 timer driver with an irfp 450.
Darwinfish4 years ago
I have a stupid question. Can this circuit be audio modulated to build a singing arc?
will these work as good coils?
Plasmana (author)  Jimmy Proton5 years ago
Yep, they look good! I can't tell from the picture, but I hope you are using enameled wire.. :)
yeah they are enamel, i am and it did work, i was just having a lot of problems cuz it was the first time i ever made one but when i finaly got it working it had a very small spark just cuz of the type it is so im going to make one of these with it. you have the most amazing instructables ever!!!
I made this using a 12v 1.5 Ah Dewalt Drill Battery, and when I powered it up, It worked, but the arc was tiny. About half a millimeter(no exaggeration). any help?
is it maybe not enough power?
I know that the xformer is good, because i made a small transistor driver and i got arcs about 2-3 inches long, and stun-gun like sparks(LOUD) about 4 inches long.
what kind of flyback are you using, is it the big one with the internal capacitor, thoes wont work very well.
its the big one
yeah those kind are pretty useless, most TVs have the kind you need
i cant find a regular one with just the core with the wire, only the big ones
i went to a TV repair shop and asked for a flyback and they game me the one i wanted for free, you can also do this at neon sign shops
at neon sign shops for NSTs, or flybacks?
for NSTs
ARJOON Plasmana4 years ago
will irfp50 work. found 5 in a very old photocopier but i also found a pcb with a flyback transformer with different outputs , it works with a 24vdc input
i -7.2kv
ii +5.5kv
iii -170v
iv +410v
v -615v
vi -290v

i will be using the +410v for my coilgun capacitor charger.

it is a 63Watt transformer marked on the red thing on the transformer that says danger
ARJOON5 years ago
can this driver charge capacitor bank for a coilgun? suppose i use another transformer that generates enough voltage to charge my cap bank
If I were you, I would NEVER try something like that; it gives out wayyyyy too much voltage than most capacitors can withstand. If you do use something like that you MUST find a way to know when yor capacitor(s) are charged or you are going to make your capacitor(s) explode. Unless you find capacitors that can withstand so much voltage(around 20kV)
no i just replace the transformer instead of the flyback transformer would it work
I don't think so, this is a fly-back driver and so it might not be able to drive other transformers... Anyway, what kind of tranformer are you using instead of a fly-back? I really don't know if it'll work for other transformers, BUT it's worth a try. Let me know if it works for you....
it didnot work however i could make my flyback transformer run on this driver it works great. I was able to change my voltage with voltage dividers but they all melted down, i think that the 555 timer ic driver will work for every transformers as the frequency can be changed using a pot
Voltage dividers on a fly-back? Thankfully you hands were away(I hope). I've only managed to increase only the voltage of my fly-back with a voltage doubler (from 20kV to somewhat 40kV)....
hopefully my hand were away,. after seeing the real power of a flyback transformer from a video on youtube i already new it could be fatal. so hands off. i recently found a big transformer in the junk. dumped by the CEB. It is about 1metre cube, the transformer oil container was damaged and the heat sinkers also. what can i do with it?????
leave it in the junk, the oil is carcinogenic!!
O.o that goes for the oil in AC capacitors?
i don't think so because there were pipes in it. nevermind i left it behind after knowing that the oil is carcinogenic no wonder why they dumped it
These things are HEAVY and kinda heat sensitive (without the cooling oil...) I have one sitting on my room and waiting to be used :(
If can LIFT it from the junk and use it without the oil, you'll probably burn the hell out of it....
CoolKoon5 years ago
Nice instructable! Let me ask you something though: how much frequency does this circuit of yours produce? According to my calculations it's supposed to be a few hundred kHz, but according to your video it's MUCH lower than that (I'd say almost as low as the the mains frequency). I base this on the fact that electricity at higher frequencies tends to behave in a different way as it does at lower frequencies (e.g. like the Tesla coils). So could you suggest a way that would crank up the frequency a bit?
Killa-X5 years ago
I like, Nice and simple, Never done it before!
robot7975 years ago
can this be hacked to use it as a plasma speaker that is what i like about the 555 it has a modulator build into it
I finally got mine working tonight. Great Instructible!
punkhead585 years ago
Unless you have a serious heart condition, 10mA is not usually enough to kill you. As a matter of fact, most non-lethal stun guns produce between 10mA and 15mA. I believe that you were referring to the lethal rate of .1A, which is 100mA, not 10. A current of this strength would be more likely to induce ventricular fibrillation, and stop your heart. However, people have died from 10mA currents passing through their heart, so I suppose it could happen, but it's not likely.
Plasmana (author)  punkhead585 years ago
They are many rules and regulations about what current can kill, I tend to stick to 10mA
Well, you can never be too careful. Getting electrocuted in the first place is not a good idea.
lol! electrocution is always fatal!. electric shocks can be tolerated if the current is below 30mA.
i think the negative gets so hot because the electrons flow from - to + (Ive tested it) and it hasn't had resistance with the air
Plasmana (author)  Jimmy Proton5 years ago
Yes.. The negative always seem to emit from the wide surface area on the wire (probably due to the electron repelling each other) but always come together and strike on one particular spot on the positive wire.
or maybe it has something to do with the lowered resistence of the heated metal. or was heated metal just a higher capatance? eh
maby it hits that particular spot on the positive wire is because electricity find the shortest path to complete the circuit and in the picture it seems its at the top of the terminal and you came from above with the negative, in other words that spot is the easiest path for the electricity to follow.
mk528155 years ago
I don't know much about electronics but what other types of MOSFET's will work and where could i order them from other than digikey. I made the simple 2N3055 driver and works fine but i want to build a new driver for more power.
noctres5 years ago
would FQA32N20C work for the MOSFET's? http://search.digikey.com/scripts/DkSearch/dksus.dll?site=us&lang=en&mpart=FQA32N20C
qwertyboy5 years ago
Rich text editor, PostCommentFormBODY_editor, press ALT 0 for help. Thanks for the awesome Instructable! I got mine up and running on the first try.

The Video:
qwertyboy5 years ago
I just ordered allv the parts from Digikey, so I should be getting mine up and running soon. For the power supply, I am using a rewound MOT with a 25 amp rectifier and filtering.
iBurn5 years ago
Quick kinda off-topic question, does your camera wig out when it gets near this, because my LCD screen just goes WHACK. Maybe just me though :P
Plasmana (author)  iBurn5 years ago
Im confused, what do you mean by "camera wig out" ?
iBurn Plasmana5 years ago
The LCD screen gets really grainy, and the RGB balance looks messed up
Plasmana (author)  iBurn5 years ago
No, not with my newer camera, it does happen with my older and crapier camera! :)
kencbk5 years ago
Nice work :) btw, will a irf740 mosfet 400v @ 10a? I'll be using 45v MOT power supply to run it
Plasmana (author)  kencbk5 years ago
They should do, though I recommend you give them large heat sinks as they will most likely generate an considerable amount of heat.
kencbk Plasmana5 years ago
thanks, your article helps alot. :) btw, i found this interesting video in youtube homebrew transistor (http://www.youtube.com/watch?v=w_znRopGtbE&feature=related ) nice video good explanation, worth trying it out thanks again
iBurn5 years ago
I read "2x small heatsink They won't be necessary if you are going to run your ZVS driver lower than 12v." and knew that you'd be using heatsinks ;)
Plasmana (author)  iBurn5 years ago
Haha yeah, I can't be bothered to take them off when Im using the ZVS driver at 12v when I know I am going to give it an higher input voltage. At 12v, the MOSFET's just never seem to warm up a tiny bit no mater how long I run it for. :)
iBurn Plasmana5 years ago
Try liquid cooling if you go really high, you'd submerge the MOSFET's in mineral oil, and maybe have a fan in the mineral oil just to keep it moving. Keep stuff nice and cold :)
Plasmana (author)  iBurn5 years ago
I could do that, but they are other drivers out there that will allow you to drive flyback transformers off the mains. :)
http://au.farnell.com/vishay-bc-components/bfc246816684/capacitor-0-68uf-250v/dp/1166123 http://au.farnell.com/vishay-roederstein/mkt1820468255/capacitor-mkt-680nf-250v-10/dp/1413770 which of these capacitors would be better for the 68uf 250v+
Plasmana (author)  HazzWold19935 years ago
The MKP capacitor ( http://au.farnell.com/vishay-roederstein/mkt1820468255/capacitor-mkt-680nf-250v-10/dp/1413770 )

Any MKP or MMC type capacitpors will work, other types of capacitor may blow. :)
great to see another hv instructable, nice work check out this thing if you havent seen it http://www.youtube.com/watch?v=655uZTywQ5I
Plasmana (author)  The 4th Doctor5 years ago
I Have seen it, I have my own verson of 'super flyback' driver, but the MOSFET get warm too quick. I am going to try build his verson soon.
eneergcam5 years ago
what could you use this for?
luudvig5 years ago
I got a bunch of "IRF640" MOSFET's lying around.. Would they work with this circuit?
Plasmana (author)  luudvig5 years ago
They will work for this driver, however, it will not work the best.
Xellers5 years ago
Nice job! You should try using a pair of those MOSFETs and the 6 batteries to test the PLL driver once it's ready to avoid spending money on big MOSFETs and a Variac before you know if it works =P
Plasmana (author)  Xellers5 years ago
 Yes.. I am thinking about testing it with cheap MOSFET's during summer holidays (I got college) when I finnish building it.
This is awesome. Much better than a basic transistor driver I have seen!
Plasmana (author)  the special terrorist5 years ago
 Yes, it is very simple to build :)
davydo25 years ago
Can this be modulated to creat audio?
Plasmana (author)  davydo25 years ago
 As far as I know, no.
Cybot Rules5 years ago
 Great instructable, planning to build it when i can order parts..