WARNING!: Working with electricity is dangerous, all information found on my site is for educational purpose and I accept no responsibility for others actions using the information found on this site.
Read this document about safety! http://www.pupman.com/safety.htm
Introduction
The Mazilli ZVS flyback driver is wellknown throughout the high voltage community for its simplicity and ability to deliver 20-50kV at high currents for a flyback transformer.
I build this circuit almost a year ago on a veroboard, but it kept blowing the thin traces due to high currents flowing. I eventually put the project in a box and forgot all about it.
Inspired by the point to point soldered designs Myke from the 4hv.org forums often uses, I tried to make something in that manner, not as pretty as his work though.
Considerations
The MOSFETs used need a voltage rating about 4 times higher than the supply voltage and a on-resistance below 150mΩ
5 + 5 primary windings are suitable for voltages between 10 to 40 VDC, at higher voltages additional windings will be needed. Experiment with the number of windings to improve performance. Too few windings will result in excessive heating and too many will result in reduced power output.
A MMC is made from 6 capacitors to avoid excessive heating in a single capacitor.
This driver will push as much power as it can, so be sure to use flybacks that can handle the abuse if you want it to live.
Specifications
| Voltage supply | 35 VDC from a rewound microwave oven transformer. |
| MMC | 0.66 uF from series string of 3x 2 275VAC MKP X2 capacitors in parallel . |
| Power consumption | 400 W. |
| Longest arc | 100 – 110 mm long white arcs |
Schematic
Construction
15th may 2009
I have now rebuild the driver using 2.5mm² / 14AWG wire for a good current ability, larger heat sinks and a MMC to avoid as much heating as possible.
Sparks
16th may 2009
I found 4 different flybacks from my collection, among these are a 1980’s Bang & Ollufsen television flyback. A small flyback from a photocopier. A flyback from a 1990′s portable television, it is without screen and focus resistor networks. A flyback with rectifier tube from a black & white 1950′s television.
The pictures with long arcs about the size of 100 – 110 mm was made with the 1980′s Bang & Ollufsen flyback transformer.
Conclusion
It was well worth it to rebuild this driver. It can now handle long runtimes with little heating despite pushing out around 400 W of power!
hi,
I am a physics student with some experience with electronics. I have ordered parts for the ZVS
driver you are using.
I have a question about the toroidal inductor. I have some ferrite toroids laying around I pulled from computer
monitors while getting their flybacks. I don’t know how to look up their characteristics to calculate the inductance. In the past I tried using a bridge and Oscope, but that has not worked well for me.
Is there a rule of thumb that will get me moderate enough accuracy to make a good circuit ?
The flyback I have choosen puts out a strong arc with my 555 driver. More so than another larger looking FB.
My MMC kinda sucks since I didn’t figure what to buy until after I spent some money, so I need to break (use) what I have first; 50, 2KV ceramic 0.01uF caps, 10 series = 1nF with a max of 5nF.
As well, I don’t have 2W resistors but do have 1W resistor….hoping that will work enough to get started
especially since I can only draw 5 A from my supply.
I’d love to make my own power supply. I have tried to make a small one for practice but the loading is confusing me. I started with 35 Vpp and by the time it as rectified and had a large cap in parallel, it was down to 3 VDC. I would prefer to make it regulated. I had an electronics lab which built a Wilson mirror and a BJT voltage. Do you have a link to a good schematic or can I use yours ?
thanks for reading all this…
cheers,
wbg
Hey wbg
I would advice you to get one of those real cheap LCR meters off of Ebay, they have a good accuracy compared to their very low cost. A LCR meter in invaluable in electronics anyway, you need it!
Salvage some MKP X2 capacitors from a pc power supply or anything else that uses them for input filtering, if you have no money to spend on these very common and cheap capacitors, your MMC is far from enough with only 1nF.
Get a variac for a “cheap” variable supply, a variac will take any abuse up to 300% of its current rating for short runs of a few minutes, with a nice lab power supply you will risc damaging it powering up circuits like these that can have some heavily back EMF through the circuit.
Kind regards
Mads
Pingback: Video of My High Voltage ZVS Flyback Driver - Laser Pointer Forums - Discuss Lasers & Laser Pointers
Hello
I am an engineer working in the maintenance of machines for laser
I want to know if you have a high-volt flybacks transformer, such as in the image
it is used in 80w laeer power supply
How much is the price
Please reply as soon as the maximum
hello!
why fast diode use?
tanks
hello!
why fast diode use in orginal mazili zvs driver ?
tanks
hi
how use Schottky diode Substitute fast diode ?
Hi, could I substitute the IRFP250N’s for IRF540? I do not think there is too much of a difference between them but just though I would double check.
Thanks,
Alex.
Hi Alex
You can use the IRF540, but only at lower voltages, about half, than you could with the IRFP250N
Kind regards
Mads
Thanks.
One more thing, is the large MMC vital? or can I use a smaller arrangement of odd value caps to make 0.68uF or perhaps even a single cap just for now?
Thanks.
You can use anywhere between 0,1 to 1,5 and properly other values too, but depending on voltage ratings, capacitance etc they will generate a great deal of heat loss, which i why I made that arrangement.
It will also change the resonant fequency of the circuit, so experiment with different values and see what performance you get
Thanks, Sorry to keep bugging you with questions like this but I like to make sure I am getting suitable components before I buy them.
For the inductor is this a suitable one http://uk.farnell.com/jsp/search/productdetail.jsp?sku=1704108 note that it IS a 2 pin inductor and the picture is just for illustration.
~Thanks.
Make your own, its cheaper and can withstand higher current.
If you use a good ferrite core you can get away with as few turns as I, if its a yellow iron powder core from a atx psu f.ex. you need 70-100 turns I think.
Thanks, So the inductor on that page is not suitable for this type of purpose?
The problem with making my own is that I do not have an LCR meter to measure the inductance of a homemade inductor.
I think I can get hold of an old ATX power supply from a relative who I will ask if they will let me have it sometime during the week. I can also salvage the heatsink and cooling fan from it.
Alex.
Alex
You should buy one of these: http://cgi.ebay.co.uk/LCR-RCL-INDUCTANCE-CAPACITANCE-RESISTANCE-METER-/230583855533?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item35afde69ad
Its a cheap hong kong LCR meter, but to the money and amateur use its accurate more than enough
I have this exact meter and it have served me well, tested up against my fluke meter there is really no difference.
What I meant by making your own is that you learn something about inductance, tedious winding work and getting parts for free, if we wanted we could buy it all, but where is the fun (or where are all my money!) in that?
I have now got the parts and have come up against something I can not find any answers for on the internet, the pin-out of the two IRFP250NPBF MOSFET’s I have purchased.
Which pin in the gate, drain and source?
Thanks,
Alex.
There is a pinout at page 8 of this datasheet for the part.
http://pdf1.alldatasheet.com/datasheet-pdf/view/197997/IRF/IRFP250NPBF.html
Thanks, I figured it out in the end and have got it up and running.
[youtube http://www.youtube.com/watch?v=ZTa8OnbYn7g&w=560&h=349
Congratulations, that is a fine output you have there, not too current heavy, so might be useful for some high voltage applications that does not require a large current.
Try to up the voltage and you will get some really fat bright arcs
I just tried it on 24v. Wow! It made a big difference, much hotter, thicker and longer arcs. My chicken stick electrode sparked like a sparkler if I let it get hot enough.
I should have a video up in the next day or so as I am going to wait until it gets dark and film some arcs with the lights off.
Alex.
Video of my ZVS driver running on 24v input is uploaded now.
I am looking forward to see it on 36V
Hi Mads, You have a really nice setup there
i will try to buy some better mosfets because mines just dies IRFZ44N and other that are non suitable for this application so my question is if i can use: IRFP240 or IRFP450 or IRFP9240PBF don’t know which(IRF450 is my choice because of the price) please let me know which of them is the best for the job.
Regards Cip
Hello
Can be used IRFP460PBF?
Diode MUR860 ZVS circuit?
I await your return
Thanks Ricardo
Hello Ricardo
I can understand from your parts in question that you want to run at higher voltages, it can be done but you might run into some practical problems like…
1) If you run the circuit from a variable power supply, you will initially draw too much current at low voltage and your components might not be able to handle that.
2) You need some voltage overhead for your MOSFETs to survive, using the IRFP250N MOSFET rated for 200 Volt, I would say that about 40 Volt is good safe limit. Thus for the IRFP460BF it would be around 100 Volt input, maybe even less.
3) Higher voltage also means that you will be running a higher Volt/turn for your primary coil wound on the flyback transformers core, this will eventually fail if its too high, you should use 8+8 windings or more. More windings will also mean reduced power output, but your MOSFETs will survive instead.
In the end there might not be a big difference in the output from going for high voltage as you have to take your precautions to insure its safety.
Hi Mads.
YouTube have recently gave me monetisation features which enables me to make money from adverts on my videos.
I have enabled them on a few of my videos already but though I would get your permission first before I enable them on the video I have embedded in my comment above. Since I followed your component list in the schematic to make this circuit I feel I should ask first before I enable adverts since you came up with what components to use.
Just let me know in the comments here, I will not be offended in any way if you do not want me to enable adverts on the video I uploaded above.
Thanks,
Alex.
Hi Alex
Its is infact Vladimiro Mazilli that deserves all the thanks for this design, just a heads up on ads, it takes years to get a payment when you are just a private person
Kind regards
Mads
Thanks for the reply. I will leave the revenue sharing for that video turned off then, or at-least until if the video ever became very popular (which I doubt it ever will).
Oh I know that it was designed by Vladimiro Mazzilli and I have given him credit in the description. (Any idea what year he came up with it?).
Regards,
Alex.
can is use the 2N3055 instead of IRF250at same 20vDC please reply me i am about to do this because this circuits gives good performance rather than other circuit i am waiting for your reply…….
No you can not, if you look at the datasheets for the 2N3055 transistor and the IRFP250 MOSFET you will see that there are considerably differences in their specifications and they are not even the same type of transistor.
I finally got round to trying mine out on 36v input,
http://www.youtube.com/watch?v=XhOqcNS6RKY
lol I originally had the same problem as you did on that photocopier flyback, my primary coil wire was too thin and started smoking!
Hey Alex
Good results you got there
Keep experimenting!
Kind regards
Mads