Tuesday, June 26, 2012

100,000 VOLTS! 2 FLYBACK ZVS!


MY WORK CONTINUES ON "Mostly Macros Imaging" but I will begin posting here again as long as this blog stays well.  I will just keep my new blog as a backup and transfer at least my main first post onto this one.  I have a lot of work to do.  I have been working on electronics and photos of my projects--I have built many in the past few months! I have taken 100s of photos which have not yet posted.  It is a lot of work and so it will take a while before I am ready to post them and I have this blog problem fixed.  There have also been some family issues that have been difficult in recent times--I will somehow transfer the posts and post many more pics of my electronics, including my TUBE (6L6 GC) flyback driver.  I am building my timer mosfet driver into a clean and small package as well.  I will update this blog as soon as I can starting with the posts done in my other blog.  I have also not contacted some of my friends lately, please forgive me for that I have a lot going on.

MOSTLY MACROS IS BACK--NEW BLOG ALSO CREATED 10-13-2012
The most important news here is that I got a call today saying this site was BACK on line!  After a serious crash and then blackout--I assumed that my blog was basically history.  I could not even access my Google account.  In turn I made a new blog called Mostly Macros Imaging which I may import or continue to use I am not sure.  I may just put a link into this site.  I will wait and see if this site remains stable.  It is very possible that Goggle simply had an error that they did not tell me about which may have had something to do with the anti-virus program that claimed many blogs were fake. I do not know, but if this site keeps stable--I will continue to post.  I had figured that all these years of work and pictures were gone.  It all came back and it looks like Google got the problem fixed!  It will take me time but I will at least post a link or move the articles from my new site into this one.  I am not sure how I am going to handle this yet.

--old news--
NORTON ANTIVIRUS SERIOUS NOTE:  I plan to put more electronics in my site--and articles--as well as new photos.  However I was shocked to see that blogspot experienced a SERIOUS PROBLEM WITH NORTON.  It says that my blog and most other blogs as well are "counterfeit" or something to that effect.  With a huge warning and some people even say they cannot access there site at all.  I had to shutoff Norton.  This is a BIG DEAL effecting 1000s of bloggers.   We are mad a NORTON and hopefully they will have the problem fixed soon.  They are apologizing--for what may be a serious problem which they claim was fixed but keeps happening for me at least.  I am sure that means they will fix it soon.  They say it was a total error-- blogs are very safe.  Unless you click on a link--you can't get a virus by going to one.



WARNING!  DO NOT attempt to build ANY high voltage devices unless you have experience in electronics and high voltage.  These devices can be unpredictable, far more complex then they look on paper and of course, very dangerous.   These pictures and basic schematics can be found on the internet commonly and are for educational purposes only.  I am an electronics technician with over 20 years experience.  Attempting to build a high voltage circuit without the help of an experienced technician could be dangerous or deadly.  Other hazards exist with high voltage as well.  I will not be held responsible for any use of the knowledge posted on this site. It is up to you to be safe and smart with any experiments you conduct.

LOOKING FOR OLD TUBE TV SETS--HIGH VOLTAGE--MY GOAL-UPDATED 10-13-2012
I have not been posting pics because I have been working.  Working on some really AWESOME circuit power supplies.  One is my variation on a simple but effective 40-50Kv (40-50,000 volt) oscillator which uses a flyback or LOPT transformer from an old color TV or computer monitor (the bigger the better) to produce high voltage.  Sometimes very high voltage, a large flyback from a large tube TV can produce as much as 50kv if it is driven right.  This can be used to run experiments, drive plasma generators and many other things such as singing arcs and Jacobs ladders.  You can also build circuits that will double or even triple voltages such as voltage multipliers and Marx generators to simulate lightning.  So to merge my two great interests of electronics and photography I built three main kinds of power supplies for extensive testing. Each has it's advantages and drawbacks.  The first one is a relatively simple 1 transistor Hartley oscillator (HO) circuit that requires a transistor you will almost certainly find in the TV you pulled the flyback out of.   It is rated for high voltage, so unlike many of the schematics on line which call for a tortured 2N3055--you won't have burn out issues if you treat the circuit right.  The 1 HV NPN H.O. transistor circuit can handle the current and voltages used since these transistors are rated for at least 1000volts! The Hartley circuit can handle input DC voltages as high as 24volts or so, going higher may burn out the transistor without serious modifications to the circuit.  Attempts at running it as high as 35volts destroyed the transistor instantly even with current limiting measures.  The flyback is driven to do several things in a TV, it runs the horizontal control for the magnetic yoke as well as generates the high voltage for the tube.  It even often provides the filament voltages needed!  It's the heart of a TV and does lots of stuff.  With the right circuit however, it also makes a great HV power supply.   You can order these HV Horizontal control transistors on line, and they are far more efficient then a 2N3055 in this kind of circuit.  These can be very efficient circuits if you get the resonance right as they operate using a feedback winding.  However, generally speaking they would not be my first choice for highest voltage outputs or amperage. They are however quick and easy to put together with just a few parts and alligator clips.  You will want to use a good heat sync.  See my schematic for part numbers.  I could get VERY technical about all of these circuits as I have been experimenting with them in depth for most of this year.  The articles on my new Blog "Mostly Macros Imaging" (I still don't know when/how I will make them visible on this blog but they soon will be) give a bit more depth to some of the experiments I have been doing. One of them explaining how I built my own flyback able to produce about 10kv and the complexities of coil/transformer winding.  I have learned a great deal about designing high voltage generator circuits with my final goal being to build a 500kv-1million volt Tesla coil.

But I do not just plan to build it, like these other circuits, I plan to understand it's design and take part in that design entirely.  So I started off here with the most basic HV circuits and then moved on to the ZVS--a great circuit for lots of applications and many would argue, the best.  It's biggest limit being that when it is used with re-cycled TV flybacks, it cannot be grounded to earth.  The 2 phase pulse system is very efficient but makes it impossible to put a grounded load on the circuit or even a lot of mass without serious kickback.  Using oil may be the key to fixing this problem--I am now working on that and just began using it very effectively.  Mineral oil is the key to all your un-wanted arc problems!  Most recently the synthetic drive circuit which is a 555 timer or other chip that drives a power mosfet has grabbed my attention.  It is not as efficient as a ZVS but can produce close to ZVS power outputs and has a very wide list of applications.  The same circuit can be used to control a motor, drive a flyback (or even 2 if done right), even drive an old 110 to 20V line transformer backwards to produce 110V again--making an Inverter.  I was able to build my own inverter this way powerful enough to light a large CFL and even a 60W incandescent light-bulb!  I was also able to get it's frequency so close to 60hz I got a clock radio to keep time! Although I admit I would need filters and more stability to get it to really keep time well since cheap clock radios have poor oscillators for keeping time and require a true AC very clean sign wave. But it does work, just keeps time a bit fast and of course the radio works fine.  Learning the abilities of each circuit and how they work as I go along has been a fun and amazing process.  I knew about these circuits but this is the first time I have really put energy into building them and studying them carefully.  I am not without HV experience and of course have a good background in general electronics--but I have never jumped into high voltage this deeply until now.  No matter what you know on paper or in theory, nothing is like actually building the circuit yourself and learning it's possibilities, pitfalls, and options first hand.  This is what makes you truly knowledgeable about a subject.  Hands on experience is very important with all learning.  However when it comes to high voltage--often the operative words are "hands off"!  The main thing slowing my Tesla coil down right now is money--my budget is very low so getting the things required is difficult and will take me at least another year, possibly more.  Looking up things on line as I go I have also dispelled a number of myths--yes you CAN hook 2 flybacks in series. However--you may not be able to unless you use a ZVS since frequency and isolation is a factor in doing this.  And the biggest problem of all with flybacks in series is the HV diodes which are usually impossible to remove.  After you get to about 100kv--the diodes run the risk of being destroyed.  So unfortunately I cannot hook 3 or 4 flybacks in series--DC flybacks anyway--without most likely blowing out one or more of the HV diodes in the flybacks.  One will fail and the flyback is useless.  This limit makes most large TV flybacks probably limited to about 80-100kv.  I learned this all too well when I got a 12cm arc going (at least 120kv!)--it looked a half a foot long!  It only lasted 30sec or so. I now use an idea I came up with a long time ago to protect circuits on all my high voltage drivers.  Just 1 50W 12V light bulb on (+) of your DC input will save you a lot of money and grief as well as show you what is going on in your circuit.  A car headlight insert or those lights you can buy at nearly any store work great.  This gives you a solid 4amps to work with before it lights up and starts to take some of the current away.  If it does--something is wrong, and since you can get 3 for $8 or so--these little bulbs are cheap compared to mosfets lost due to ZVS meltdown!  Even if you power supply voltage is 50V--you can use just 1.  Going higher I might run 2 in series, but even if it does turn all the way on your bulb will act as a fail-safe and visible fuse.  Great for trouble shooting.  Desk lamps and other devices use these little 12v 50W bulbs--they often come with a small reflector built in.  If you want more power you can get 100W by putting 2 in parallel.  They have saved me a lot of money and effort in trouble shooting and I will mention them more later.  One of two flybacks in the ZVS failed when I bypassed my current limiting.  After testing the flyback in a number of ways (even building a resonance jar that will produce a voltage in any coil placed in it) I found the only thing that made sense for it's failure were those pesky diodes and that one of them just shorted inside the flyback once it reached it's peak voltage or got too hot.  I miss the days of tube rectifier HV.  You got an AC or DC flyback and it was YOUR CHOICE when you took the TV apart.  I sure wish I could find more of those today!  That circuit is later--first--check this out. 


"Plasma wall"
A WORD ON SO CALLED "MILLION VOLT" STUN-GUNS-- the companies lie!
This is a Jacob's ladder making a plasma wall--pretty cool!  However--we are not even getting started with arc size.  This is about 40kv.  About 40,000 volts.  Most large flybacks can be pushed to 35-40,000volts without damage.  The same more or less--as most stun-guns and Tasers.  Which also use HV didoes and capacitors to produce a "punch".  I have bought about 6 stun guns over the past 15 years from several different companies and tested them.  Now days, they are saying they have as much as "7 million volts"!  Police, security--and everyone else--should know that this is a LIE!  For reasons I can only speculate they lied after they actually lowered the voltage from nearly 60-100kv in some units to about 40-50kv in most quality units now.  These companies decided to do this after complaints created by "kickback" which was impossible to control due to those large voltages arcing so easily.  You got shocked at the same time you shocked anything else.  Not cool!  Lower voltage however does NOT mean the stun-gun will be less effective against an attacker.  Actually using less voltage and higher current at a good pulse rate is a better idea--and this is why all pretty much all TASERS are 50,000volts.  However, how could they go from saying 100,000volts to 40,000volts!? It sounds bad. People would ask "where can I get the high voltage" when they really need to think about current, voltage, and frequency--as these matter far more then voltage.  But most people think that voltage is everything.  Not true at all. You can get 500,000volts from a Snuggie or blanket in the dryer!  IT does not kill you because it's current is very low.  So I guess a need to counteract useless fear over lower voltage prompted by bad kickback problems with the higher voltage models--they just started lying sometime in the late 1990s or so.  This is simple--and I need only say it once but everyone should know this--the best STUN GUNS you get will only give you about 50,000volts--even if it says "7,000,000volts".  The same (usually less) as you get from a police Taser. So cops should NOT be arresting people because they are selling or having these "million volt" super-stun-guns.  They are not any worse then they were before, no new magic has made it possible to get millions of volts and there is no reason to even try.  I own several of these stun-guns and I tested them myself.  I have been stunned with them as well, so I know!  I have also been a security guard. So trust me when I say from an electronics standpoint--they are just trying to sell bigger and better models and the only way to get to people is to tell them they have "millions of volts" now.  Tests show that often these new even very expensive stun-guns put out only about 30-50,000volts.  Giving a comparable shock and CURRENT to that of a police TASER.   This is important--since this issue has caused arrests when cops thought that you could make or they are selling "super stun-guns" that are thousands of times more powerful!  The only way to make a "super-stun gun" is to build it yourself and it would have to be very clever.  For millions of volts--something about the size of a small bag or briefcase holding large capacitors, voltage multipliers and a driver like a ZVS.  It takes serious technical knowledge to do that.  The parts for ANYTHING that can make millions of volts cost hundreds or even thousands of dollars--so doing it is very difficult and requires usually a very large coil like a 3 foot or more TESLA coil hooked up to very serious vacuum capacitors.  So lets get that MYTH about "million volt" stun-guns--out of the way!  It just is not practical or possible in such a small package.  Not at any useful current level anyway.  Most smaller, cheaper or 9v powered stun-guns I am sad to say, will only give you a hard-buzz and are not likely to knock out anyone let alone repel a mad and angry attacker.  If you get one--and I do carry one myself--get a rechargeable powerful one--and it may say "7 million volts" but it's really about 40 or 50,000volts which is the same as the police units.   Why they chose to possibly harm business with this lie I am not sure.  I recently saw an episode of a show like Cops about this- the cops were afraid of these units and talking about them as if they were very dangerous.  I can't stand it when people are not informed. It is simply a lie to sell more units.  And the lower currents they usually put out are less then police TASERS.  Some of the lower priced models are ok, and will disable someone if put in the chest or neck area.   However--make sure you test it on your leg--and do not buy a DOUBLE UNIT--they tend to go into high-frequency oscillation and loose there kick if both units come into contact with something.  This is no good!   The rechargeable ones seem to be the best--but I can promise you that none of them are a million volts.  Lower still in current, over a million volts is produced when you take tape off a scotch tape roll!  This amperage is so low it takes special gear to measure it and you don't feel anything.  But it can fry sensitive electronic parts.   Many problems would exist with a million volts in a box that small in a viable form--for one thing the diodes need to be larger to handle voltages like that, the coil has to be big enough to produce it at any viable current--and voltage multiplication capacitors at those ratings are very expensive--even in China!  So if you get one--be sure to buy an expensive unit and know that it's only about 50,000volts.  40-50kV is all you need--at the right amperage--to bring someone down.  The electric chair uses only about 2000 volts (at very high current) to kill someone.  So why all the hype about higher voltages?  Current is what kills or harms.  If you live in a state where they are legal, you also might want to brag only about your stun-gun being 50kv--and not have the sticker on it that says is "millions of volts".  Some cops might think it's illegal.  This is all so stupid, since it's really the current and frequency of stun guns and TASERS that bring people down, stun, hurt or could kill--NOT the voltage.  Even so, although it is possible the flybacks in some produce up to 100,000volts or so--arching several inches, it's really not a good idea to attempt to use that kind of voltage in such a small package with cheap parts and tiny batteries.  I knew this all along but even so ordered several different units and tested the voltages just to be sure--I was right.  The highest voltage I have ever seen from a Stun-gun was far less then what my ZVS produces--at far less current.  Way less then half the current.  To sum this up, they decreased the voltage in recent years in order to prevent problems with higher voltage systems in small packages--kickback getting to you.  So I guess they had to compensate by saying the voltage was higher to make people think they are more powerful.  They did increase the current in some units to better levels.  Notice how the prongs in recent years on most stun-guns have gotten closer together?    There is no need to make laws or be afraid of these things--they are very useful for repelling attackers without harming them permanently and should be legal in every state.  Voltage lies continue to keep this from happening in some states.

 This ark is about 1 and a half inches long and was produced by a relatively simple system of using a large Color TV fly-back coil.  Tube TVs require high voltage to produce an electron beam to light up your screen and draw and image on it.  This voltage varies, but most fly-backs can produce more then the TV uses.  So you can get about 35,000 volts out of even a small one.  Fly-backs are far better then ignition coils for raw voltage.  Ignition coils force you to ground one end to the input and are already in oil.  This is good, but upper insulation makes it very difficult to push them as hard as you want.  They are also built for low frequency and higher current making them more dangerous to humans. The low frequency part makes using them for plasma displays very painful! Typically you only get about 10-30kv out of an ignition coil before it starts arcing through it's insulation.  You could put one in oil and probably get 100kv out of it if you pushed it hard enough, but there is a danger of damaging it or melting the wires.  They are very good for anything you want to have arcing all the time as they were built to handle shorting out at high voltage and high current.  It takes some interesting circuits to drive them and I don't want to get even more technical here--if you want info email me or look it up on line, a 555 timer system with a large power mosfet would be a great choice.  They are small Tesla coils but cannot be run at high frequency so they are not much fun for plasma displays.  Like flybacks, despite ignition coils being low frequency--they are built for a DC and they will NOT operate at AC line voltages/frequency--like 60hz. They require a higher frequency.   Flybacks are a great choice for lots of things but the older the better. If you can order an AC flyback on line or get one from a really old all-tube TV--you got it made.  Often these connected to a large tube which rectified the voltage into DC.  SO this cap is your output rather then a suction cup for the tube.  Ground was often just the chassis.  These AC flybacks are an awesome find, a few companies also still make them.  The new ones have diodes embedded in there coils.  This makes the newer ones (made after the 70s or so) only good for some applications.  Since the diodes cannot be removed. However, the older all-tube TVs and some other TVs use a tube as a rectifier or external diode, this small tube will have a cap on it and be connected to the fly-back--this means you are lucky and found an AC fly-back!  Keep it and treat it with respect and care!  They are hard to find now days and great for making plasma displays and other stuff.  IT is nearly impossible to remove the diodes from most modern fly-backs.  However, arcs and many projects can be produced even with them in place and for some projects the DC is preferable to AC.  I use the arcs for photos and plan to post many more now that I have the power systems built.  This is one of the first schematics I drew of my 1 transistor Hartley design.  It came from an internet design which I modified to include a better transistor and use the flyback's internal windings rather then winding your own external ones.  There are some very serious reasons why you should NEVER break off those pins on the bottom of your flyback or cover them up!  The arcing can be controlled by using hot-glue or better yet MINERAL OIL.  Just submerge the entire thing in it, and run leads out of the jar it's in with hotglue to seal it up as much as possible.  Good Tupperware containers work for this, I will show this later.  This lets you run flybacks as high as they can go without any arcing that is not wanted and do things like run them in series.  My new power supplies have flybacks in oil just to make it more easy to control and use.

Here is the schematic.  Sorry about the light, I draw my schematics in pencil and don't have the software to make them on computer yet.  I have been hand drawing them for 20 years so I'm used to it.  This was my prototype basic schematic right out of my notebook--lacking lots of details or really nice drawings--so forgive the possible things left out but I assure you if you follow it it will work.  I found that you need at least 5W-10W resistors for the 220ohms and be sure to get a high voltage transistor from an old TV--you will clearly see it, usually it' marked with it's contacts and most of them are NPNs.  It will be connected directly to the fly-back in the TV which is drives.  So it's only natural to build the driver out of the transistor from the same TV!  Just because part of a TV died, does not mean the rest of it is.  Dead fly-backs and driver transistors are relatively rare.  The driver transistors are so difficult to turn on it takes less then a 10k to turn it on!  Once this circuit is going, hooking it to a power 20W 8ohm resistor is a REALLY good idea so that if anything is wrong you wont' fry everything.  Then use a good supply, regulated or high amperage--to run it.  Don't run it above 24-26volts.  I HAVE TRIED and trust me the transistor will fry unless you re-design the entire circuit.  Be SURE to use a heat sync and remember--the wires in the secondary (high voltage winding) of a fly-back are thinner then a human hair!  if they break or short--that's it. So don't arc it into oblivion if you want to keep it going. Check temperatures and only run large hot arcs for a short time.  You will have to find the leads here--this kind of circuit does not work very well with an external winding done yourself.  The hardest part about building this circuit is probably finding the right leads to use.  You need the primary coil--usually off by itself shown on the bottom left--and then you need the feedback coil--one of the other coils in a fly-back that will work as one.  This makes for some great output. You can wind your own--but as I say it's better to use the fly-back's windings as they are setup really well for this kind of driver. You just need to locate them by experimentation.  Polarity of BOTH sets is very important and must be right, so use a large resistor to find out if your circuit is working and find the leads without damaging anything--like a 50ohm, and an EMF meter--and then alligator leads to see when it starts to oscillate and produce a bit of high voltage. If the secondary is wrong a tiny high voltage may come up--be sure to test both directions while in a test mode (using a 50ohm series resistor) Then kick up the voltage and remove the 50ohm current limiter. You will either hear a sound and get almost nothing--or get lots of high voltage and hear a sound.  If you hear a sound and get no high voltage--reverse BOTH of the primary coils polarity and you should get things running.  The high voltage should hiss and then draw and ark--you will also need to short out the two pins usually close to the focus module.  This is a large coil that is connected to the secondary and thus must be hooked up.  This is true with every flyback I have seen.  In fact you find ground by seeing what pins arc together first at the lowest power input, short them and then solder on a wire and that's your HV (-) .  As far as using homemade coils--for feedback they will work fine in fact playing with this you could get to the resonant frequency of the flyback and produce a really high output--but wind the whole thing?  It works, but not very well.  If you wound A LOT of turns on it maybe--but it's best to use the fly-backs built in coils for this one.   Kickback volts will happen depending on your load and setup--use a 10k and 0.1uF cap for that in several places and or large MOVs. There are other ways but this transistor is so tough that you can operate it for a short time with the leads arching from emitter to base to collector!  I've seen it!  You will want to KEEP ALL ELECTRONICS including your phone and laptop--AWAY FROM THIS CIRCUIT and any other parts you intend to ever use again. IT produces a very active electrostatic field due to the low frequency oscillation it makes.   So it can fry things at a distance.  Don't get your digital camera or laptop too close!  Once is all it takes.

THE AWESOME ZVS!  (Zero Voltage Switching) driver-->

Several names are attached to this circuit which in itself is also pretty simple if your not a beginner.  This circuit was apparently designed by Vladmiro Mazilli according to the internet. It is basically just a push-pull mosfet oscillator with a lot of advantages and uses.  There are several versions including the one shown here which is my take on it.  I changed several component values and added a 2nd fly-back in series--breaking what many on line said was impossible.  And this is not just an effect due to 2 identical or lucky fly-backs--I have tried this now with 2 other fly-backs and it works just as well!  The ZVS may be the most powerful, versatile and trust-able, circuit for high voltage production.  Great for lots of stuff.  It produces lots of current, and lots of voltage from a fly-back or as I have proven is possible--two.  On this circuit you want to keep things to about 22-40volts and no more unless you change values.  At that voltage range you will have a lot of fun!  I found that hooking 2 fly-backs in series is just a matter of frequency and making sure that your ZVS is setup for it.  There is only 1 ZVS driving both fly-backs the ballast 12V 50W lamp which is in my schematic--I will add here soon.  I will put my schematic up in full later when I have it properly photographed.   As you can see, power is just pumped into the flyback with a coil of wire, 3x3 or 4x4 turns should be fine. Keep leads short and neat, despite what my circuit looks like!  See my finished supply--the CD-707 for a full system that works well.  This one is the prototype only.  The capacitor MUST be directly connected in the system.  In other words--if one wire is 1in going to one drain, and the other is 3 inches--it may not work!  One must experiment and build a clean circuit if you want it to be stable. Depending on lots of factors including your DC supply voltage and frequency--more turns might NOT be better.  I find 3x3 to be more then sufficient at AWG #22 hookup wire. Just be sure to use large insulated wire, it will get hot even if you do.  One flyback homemade winding is center tapped and goes into an RFC.  Be sure to chose a powerful one (2amps+), a 100mH I got at Radio Shack worked fine.  This choke the drain capacitor and the resonant frequency of the coils you use direct the operating frequency which can be quite high.  Unlike other kinds of driver's--the ZVS automatically will tend to operate towards the high end of a coils resonant frequency and pulls little current when nothing is being used.  It's a very efficient circuit.  It also does not create very much low frequency static/harmonics and does not use any part of the flybacks own primary except the ground end of the high voltage--so connecting them in series is easy since the homemade primary coils are isolated from the flybacks windings electrically.  Use a strong wire with good insulation and put in an oil filled tub as a separate unit to contain the HV DC electrical field for best results.  Out of oil they are limited to the flyback's insulation capability.  Regular mineral oil available at almost any drug store will work. Kickbacks can burn through this insulation so be sure to use hot glue at the bottom to cover the core so that arcs do not get into it and thus make it through your insulation on the primary wire if you are not going to use oil

I have lots of advice but I can't put it all here.  The complete computer-drawn schematic for this will be shown later.  My version became different from the version I got off the internet and drew on my notebook, but that is a start and that will work for one flyback.  First off, if you get those $3 Chinese bread boards--remember--each terminal is not like in the USA!  The terminals for power on top and bottom are only connected together every 2 x 2.  So you have to put in jumpers or you might spend hours wondering why your circuit does nothing at all!  I tested every part and only when I'd tested everything did I figure this out!  The capacitor is around 0.22uf and remember it gets HOT! Use a large one HV AC cap. and short leads. Find the right one, at least 200v. 0.2-0.7uf  My biggest peace of advice is to get a large current limit device--like a car front headlight--the 12v 50W ballast bulb.  You can find them in many places that are small now days so they won't take up lots of space.  They pull about 2-5 amps--so your circuit won't even be very limited unless it has a problem.  This circuit needs some serious amps to get going--most on line articles say "lead acid batteries"--like car batteries-- laptop batteries would be great but they must be modified first.  Laptop batteries may overheat or switch off, possibly even blow fuses if used with this circuit.  I use a Variac that is fused and bridge rectified to give me a large choice of voltages but do not go too high!  Above about 40% or so could damage flybacks!  They die very fast.   As I say--this 12v ballast bulb saved me more then once--to make sure you don't destroy all your components when you have a failure.  Experimenting with a new circuit there always is one problem at least!--use a 12volt car head light or desk lamp 50w 12v and your good to go. If it glows at drawing an ark then it's at the right time and you will know when your circuit is running well, it will glow slightly like a radio tube in normal operation--even at 45volts.  If something is wrong, it will light up really bright or even blow out if your using really high voltage and no other current limit systems--I use a good 3ohm 25w resistor at least too--ceramic so it can stand higher levels to protect everything a bit more.  It is not only a valve to stop wires from melting (and at these amps needed they can!) but it will stop one burned out part from cascading into another and burning it out.   The whole thing would have gone up in smoke twice now had I not used this method.  If you really want to see it fly and possibly fry, and add about 2cm to you already insane 8-10cm arks--remove it for a moment.  But watch temperatures.   The 2W 470s should really be 5W.  I changed that to 1k as they overheat quickly.  Whoever designed this circuit should have realized that.  The Zeners are there to protect the mosfets from exceeding 20volts on the gate. Thus they can be as high as 18 volts or so.  I use 1N5353 There are lots of cool things about this circuit but it requires lots of power, so I built an 4 level power supply for it.  Here I have 4 settings from about 10kv to 100kv on the system in a relatively small box for this many required amps.  2 switches control the DC output.  (In this case I am not using a Variac) Current limitations should be used for high voltages over about 100kv (10cm sparks that START at 10cm NOT draw out to 10cm!) you run into problems that might fry smaller fly-backs.  Don't push things too far or too long, using one flyback, I would not exceed an operating voltage of about 24 volts.  I am not sure you can push more then 2 fly-backs at once.  If you could you might be able to get a foot long arc, but I am afraid that may not be possible due to limits of flyback construction due to those HV diodes.  For unwanted arching at the bottom--use hot-glue.  Or just submerge both of the fly-backs in transformer mineral oil.  It can be removed and it is nearly a perfect insulator, non-toxic and has no odor.  So it stops arching very well.  Hot glue is also a great insulator, I use hot glue all the time and it's really cheap.   I would NOT break off any leads to stop arks as someday you may want to use those flyback leads in another circuit and really regret it.  Start out at about 22volts, no more.  If you start too low the circuit may not start to oscillate on it's own.  Keep leads to the hart of the circuit--the capacitor across both Drains (0.22-0.7uF 224-704-capacitor code numbers ("XX4"=0.X)--short.  Many of these can be found in computer monitors and tube TVs.  This part must be in good shape and checked heat, the circuit will do nothing without it.  And be sure to use a heat sync on your Mosfets. I use IRFP250s and have gotten used to them.  There are several kinds with different prices and sizes, do not use smaller power mosfets without checking specs!  IRFP250, 260 and 460 all work well.  Mosfets are actually also STATIC SENSITIVE so make sure they don't get too close to the HV.  The diodes are  FAST diodes--you can order them on line.  400+volts or more. (example:UF4007 --NOT 1N4007!)



Here we go-- 100,000volts or more.  Better pictures to come as they are already on my alternate site.  It is difficult to tell without about 300 mega-ohms.  I am working on that to get really accurate high voltage measurements.  I currently can measure only up to about 40kv.  The output here is near maximum but it will put out a bit more if I pushed it too far which might fry a flyback.  Use 2 large (30+ inch tube TV) ones if your going to use 2.  Be sure to get a good idea of what you can do with 1 flyback first!  I got the idea to prove and see if it could be done since I read so many people on line saying it could not.  You just have to take some special precautions and do things right.  Problems have already happened once.  My arcs for a very short time reached nearly 15cm-cold start!--but one fly-back stopped.  It took me hours to figure it out but when I did I was surprised after seeing so many high current large arcs pulled on U-tube out of sometimes small flybacks.  I have heard of other people blowing up flybacks, but usually it's from charging them with the wrong kind of power (like a 12v transformer or even line current!) --or using a ZVS to push them way too far or just letting it arc to itself or the core.  Often these videos are done however, without a ruler or stuff to really show size, so I thought I would prove my 3-4 inch ark--with one.  

 Here is another picture.  The ark is less then 2 inches from the ruler.  Showing how long it is to some degree.  The picture below is even better.
 Here we see the ruler being shocked with two arcs, this is because as you might know--old style wood rulers have a metal rod at the end of them for drawing lines.  This metal was a quick find for the HV which made it there very fast at 100,000volts!  This would be a "super-stun-gun" but look at how large it is!  You could not fit it in your pocket!  You can't run something like this off 9V batteries for long. This thing pulls at least 2-5amps at 40volts with the car headlight as a current limit 12v 50W X2-- and 3ohm power resistor.  So the power draw is about 80W+--most probably 150-300W or more with less current limits.  As I say, be careful, even with current limits, running this for more then 1min or so is pushing the flybacks hard if arcing.  This is built for momentary things like photography, not Jacobs ladders and stuff--but you can build a ZVS for that which will do great.  I even put a relay on it for a small hand operated on-off control.  This lets me arc on or off for photos when I want. I can also hook a CDS cell up to the control board and have it turn on or off with lights.  A simple circuit could also turn it on or off with an IR remote although interference from the arcing makes that difficult to do.  RF control is possible if you use FM or UHF--as long as the arcing does not create too much RFI. Arcs this big are serious and really show power.  You can feel it.  I would not want to be shocked by this, it probably puts out 1ma at full voltage but if loaded ma will increase to as much as 50 or more at less volts but still 10s of thousands. That could be enough to kill if you got hit with the full current.  It is always good to have an isolated safe switch that requires you to push it in so that if you are shocked you will shutoff the device automatically.  Just be very careful around ANY high voltage and unlike these pictures--use some HV cable for hooking things up--as it quickly arcs through the insulation on these kind of leads.  You can get HV cable at auto parts stores.  Ignition wire cable works great.  A simple bifilar-wound toroidal transformer placed on power or one on each gate of the mosfets will modulate it and create a huge singing arc!  I am not sure how long things will hold up if current limits were taken off, temp is good, but the fly-backs are taking a lot of power.  I wanted a big spooky old movie arc, so I came up with a new kind of ZVS for what I needed.  I chose 2 fly-backs that use a small electrolytic capacitor and current limiters to produce less current put more volts--it works great.  This is the largest high voltage supply I have ever built (as of 2012) and I built it from scratch.  For an updated schematic--stay tuned to my site. UPDATE: And my other sites articles will soon be here.   I will also be adding more pics at higher resolution of the arks and things arching into stuff as well as the DC plasma and particle photos I built this for!

This is the basic schematic I started from on line.  I drew it again fast--and have yet to complete and photograph a full version of my ZVS system.   My revision now includes a redesign of this circuit that allows for more power and a variable output.  The CD-303 and CD-707 homemade lab supplies. UPDATE: I have now drawn on computer my version of this circuit for running 2 flybacks and it will soon be posted here with more pics.  It differs in serious ways from this one, but the basic principle of a ZVS is the same.  You can get large and awesome arks with this circuit.   This is right out of my notebook.  There are also many on-line resources--just Google "ZVS driver" for those articles. Click to view schematic better. If you have any questions please feel free to ask.


And here is the prototype in full operation!

14 comments:

Unknown said...

Im a Highschool student, In a biotech group as the hardware engineer. i only have 1 flyback are you telling me i need to chain them together?

Gabe W. Beasley said...

Hi, I responded a bit late and if you got my first response I decided to re-do it. First of all, simply, the answer to your question is yes.

I think it's great that you are active in building electronics in high school. I saw your profile and noticed you built a plasma speaker. So I must assume you have some good working knowledge. If you can read schematics I have a number of them for 100kv supplies. However, this is not an easy thing to accomplish. A parallel connection between two flybacks simply increases amperage and NOT your voltage or initial arc length. I don't think you have any use for that in what you are trying to do here unless it's for a plasma speaker. If you want really high voltage from flybacks, it is good idea to take a look at my schematic of the ZVS circuit I modified. I also designed a variable version that can be built out of easy to order parts. However, everything from a wires that are too long to not having the flybacks isolated in mineral oil (available at most stores/pharmacies) can be a big problem. Few people try or succeed in connecting flybacks in a series system because of how much can go wrong and how difficult it is to control unwanted arcing. I came up with the oil solution to much of this on my own. The best way is to put them both in oil. It is possible to do about 80-100kv without it, but you have to be really careful due to the large electrostatic field produced. This can fry things like cellphones and can also damage or cause problems to your driver including serious arcing even if it's grounded. And your low voltage supply always should be. When flybacks are in oil, this field is almost neutralized due to the oil's very slight conductivity. It makes things a lot more neat--the oil is non toxic, unlike many transformer oils. It works well.

First off, think of this like 2 batteries. In series, the plus to the minus terminal. IN parallel the + to the + and - to -. Series of course, just + to - and then you have a combined voltage at + and - between the 2 flybacks or batteries. It would be best if you can find a teacher or instructor who has a serious knowledge to help you with this project in your area. Possibly someone at a local collage or ham radio club? This is not super easy stuff. High voltage is more unpredictable the higher it gets from a piratical perspective.

Gabe W. Beasley said...

Your first flyback may work with another, but I recommend that you order a couple of them from ebay. You can get them for as little as $12 most of the time. So if you can get the cash, buy 4 of them. Just so you don't have to worry about the inevitable--flybacks often don't have datasheets and are very easy to overload even if not being arced. There is no warning before they go and no way to fix them. The wire inside is as thin a human hair. Many things can go wrong. Never arc one for more then a few minutes if you really value it. They can handle a lot but when you get to what they can't, they go quick. Especially at voltages often used to power push-pull drivers like the ZVS. A PWM is another choice, but you will need a large mosfet. A full bridge driver or just a half wave single mosfet driver will work fine. It is pretty simple to build a PWM type driver with a 555 timer and mosfet that will get you what you need. Your going to need at least about 4amps of power at 24volts or so. You can use old laptop batteries, car batteries, or build a high current power supply if you want.

You will have to find the grounding PIN on the bottom of the flyback. It is best to use two identical flybacks. Often this is possible by ordering them through ebay. I should note here, you can buy 50-60kv very high voltage flybacks from several on-line companies, but they are expensive. The size does not matter much as long as they are not extremely small and as long as they are not more then about 30 years old. You must not get the type used in computer monitors--as those often use voltage multiplication rather then the coil to diode system that color TV units do. This can be a problem for series connect circuits. Ignore and remove all extra wires that are on it, (not the pins) those are NOT the main ground to the coil. Most people don't know that flybacks have several diodes in them. The high voltage is created with at least 3 coils in series, sometimes as many as 6--and between each coil to the next is a fast high voltage diode. I did not reflect that in my schematic as I did not want to confuse people thinking that extra diodes were needed. None are unless your using a really old flyback that is from the tube era. These produce mostly AC.

These diodes are only good for about 10kv-20kv each. But when in series, they can handle a great deal more. I have gotten 70kv out of a single flyback, but it quickly died. The max you want to ever pull is about 45-50kv. Which should arc 5cm or so (not drawn out! point to point.) if you live at or near sea level. 1.1mm=1000kv (arc size reference generally) At high altitudes arcs can go considerably further. Some flybacks have a really hard time going that high however, and there core will saturate before it's possible. Some are just not going to make it past 30-40kv. Most on ebay bought as NOS however, can. This project is too complex for me to fully explain here. There are so many things that can and do go wrong if your not really careful. IT is very easy to hook one flyback up, but using a number of them requires a lot more consideration and a good coil driver. There are a lot of variables.

Gabe W. Beasley said...

Ok, so first-- Locate the ground pin, fire up your flyback at low power, such as running it on 6-12volts. If you don't know which one it is you should find out. One of two things will happen, an arc may appear (as you begin to reach full power) between two pins. Usually that's what happens. Those two pins can be shorted together and this becomes your ground. That is the most easy way I can explain it. Or you will see nothing and you won't need to connect any pins together. However, without doing so if not in oil these pins may arc to the core or in unwanted areas. You can try to hot-glue them, but I don't recommend breaking them off. They will be useful if you learn how to use them eventually. To find actual ground pin-- Take a wire connected to NOTHING very carefully holding it with a plastic ruler (tape on or
something) and find the contact which produces the largest arc to the open and unconnected wire. It should only be about 2-5mm and really small. Once you have done this--you know the ground pin of the flyback. Make sure the hot lead is sticking out somewhere safe, it's elecrical field will allow a spark to be produced by your wire connected to nothing. Be sure everything is insulated and such. The other wires that seem to be ground are usually operated through variable resistors that will act to focus a CRT. Don't bother with those. Once you have found the ground wire, as you bring up the voltage--you will notice the arc. With a good power supply, I strongly recommend you don't go above 25volts into the flyback driver. It takes only 6 turns with a ZVS type driver #22AWG solid, DO NOT used enameled wire to make a primary on flybacks. You want lots of insulation. A cut up old extension cord will work fine. The primary you wind yourself. Also, never think that the core is grounded--most of them are not, if you use it as one--it may arc into the flyback eventually and destroy it. Flybacks will overload without warning. It is very easy to miscalculate or overdrive them. Once dead, that's it. The voltage get cut in half, cut off all together, go AC, or it will arc somewhere impossible to stop. That's why I say go to ebay and buy a few flybacks from a supplier that has the same type. They do not have to be large, just about 3 inches high and maybe 2in wide. You will want to use highly insulated wires to wind your own primary. You can get great results by using the primary built in--but I can't explain how to figure that out here would take too long. I hope this helps--as I say I can only offer you a basic outline. There are so many things to learn and things that can go wrong. But I've been successfully doing it for years. Once you get flybacks figured out they become easy to use with lots of uses. I recently built a working ion drive model powered by my variable supply. It runs at about 20kv. Be very careful. Two flybacks connected together can put you in the HOSPITAL or worse. Please take extreme care when working with high voltage. 100kv will arc more then 100mm up to about 4.5 inches.

Gabe W. Beasley said...

So if you can find the ground pin, build a good supply for low voltage with high current and then a driver, you should be able to put them in oil and connect the secondaries in series by soldering the hot lead (the large lead on top) to the ground of the next flyback. I have successfully done this recently with 4 flybacks using a 1000W driver I designed and built. It is capable of producing a 7 inch arc (in theory could produce up to 9inches+! but I don't want to blow the insulation. It thus generates about 200kv. It was very difficult to solve all the problems needed however it is now a stable part of my lab I use for all kinds of experiments. Checkout my YouTube videos. I'm under the channel "mostlymacros" there too. Your best bet for a driver is to use a ZVS since it is not that difficult to build and will generate a good high frequency that is self-resonant. Flybacks have a powdered iron core that makes it possible to run them with a wide range of high frequencies, but they do not work at very low frequencies. For example, trying to power one with 60hz would give you almost no output no matter how much you put in because the core is designed for high frequency. Eddy currents essentially short out low frequencies inside the core itself creating a "shorted" electromagnet. Too high frequency, such as several megahertz or too low won't work. However, you can run a flyback at very high frequencies. This has advantages. Our world today uses them everywhere. Switching power supplies use transformers very simlear to flybacks at lower voltages run all our plug-in tech today pretty much. They use the same idea. If they did not, you would need a box as large as your computer just to power it! A 60hz transformer would weigh about 15-30 pounds and be very large just to get the same amount of power you can get out of a small 1/10th of a pound powdered iron core operated at high frequency. This has to do with the flux density of the core. High frequencies are far more efficient in these types of transformers so you can have one only a couple of inches long and high but yet can run 500 or more watts through it. Without switching supplies, everything we have like a computer would need a second box nearly as large with a huge 60hz transformer in it just to generate the amperage needed to power your computer! 60hz however, is better for long distance transmission lines, so that's why we don't have a 500-5000hz line frequency. There are a lot of complex subjects to think about with this project, but if you can power one flyback and get a good large voltage out of it, you should be able to parasitically connect a 2nd in series or parallel--the primary side--so that you can run them together series on the secondary. Remember, PDC is what comes out of a single mosfet. Pulsed square wave (usually) DC. That is, it's not true AC. So polarity matters! Only a push pull circuit or full bridge driver will give you AC. A ZVS is one of these types of supplies. If you use PDC one polarity will give you a strong bias of current but very little voltage comparably on the flyback output. At the reverse polarity, high voltage as you want, but at lower current as there is a complex trade off I don't have room to explain here when you use PDC. Suffice to say it works well to power transformers and flybacks, but has it's drawbacks for some applications. I recommend you use a large mosfet for this. Your best bet would be the IRFP260 or IRFP460. These are two really good mosfets I use often. Make sure they have large heat syncs and check temperature all the time. If you get more then about 5cm arc when it starts, the flyback is probably right at it's limit of breakdown. It is often best to use some kind of ballast to take voltage away from the flyback(s)when it is under stress such as arcing. A large resistor, wire wound, like a .5-4ohm at 50-100w-- or you can just buy a 12v halogen bulbs that require 100W.

Gabe W. Beasley said...

They are not that expensive and you can get them at most stores. By putting these bulbs in series, you limit the flybacks current to about 4amps. They will glow brighter as you pull current but prevent the flyback from being destroyed. Be warned however, even if you do this, you can still run too many volts into it. My rule is to use a ballast and not generally run more then 25volts into a single flyback. I have often used x2 12v 50w halogen bulbs in parallel as a current ballast for flyback supplies but depending on how you are powering it, you still need to limit your voltage so that you don't end up damaging the flyback. It can be tricky, and may take many tries. As parts can fail and flybacks must be operated on the edge of overload to produce such high voltages.

Good luck--and I have a question, what are you going to do with this project??

Remember, running flybacks at these levels will be a large strain on the multiple diodes. This can be a real problem. If you want to do a singing arc with it, I would not use this kind of setup. The diodes in most flybacks can't handle that kind of current load for more then a few seconds. A singing arc is best accomplished with another transformer or a 2 or more flyback parallel supply for current. It is possible but as I say, they would not last long. You would be dissipating about 7amps (on your drive voltage side) through two flybacks in order to get a full plasma arc reaction needed to create the singing arc effect. This is an overload and if they did not overheat they would blow there diodes in a very short time. Anyway, as you can tell this is a complex subject. I have only touched on a few of the basics. With luck, you should be able to get a ZVS type supply to do this more easily then a PWM. Hope this helps, just be very careful--remember it only takes 30ma (0.030Amps) to get electrocuted! Don't take any chances.

G.Beasley (KF7DFP)

Gabe W. Beasley said...

Wow! I did not realize I had wrote a book in here--had to break it up into sections. I'm a fast typist, hope this helps more then my first comment. Good luck.

Unknown said...
This comment has been removed by the author.
Unknown said...

LoL thanks for responding in such detail. i just now got another flyback from a CTV i found, I also have 2 MOTs, Along with the Caps the microwaves had. I have a lot of stuff i just go out and salvage, i'm getting a duel channel 100mhz Oscilloscope for my birthday, when the school year starts i was going to study how wave length effects arcs of plasma, i was thinking of using a Solid state Tesla coil. I also work with the biotech group at my school which is where i do all my research. I did make the Plasma speaker, but it produced a large amount of Ozone, which i idiotically inhaled, which destroyed my lung tissue and ended up with me missing a week of school while i had bronchitis, so i have another factor to worry about.

Gabe W. Beasley said...

No problem, yeah I've had my issues with Ozone as well! IT is a highly corrosive gas. A good fan outside should prevent buildup. I am glad to hear you have a goal and plan to go somewhere with your interest. I feel compelled to warn you about MOTS. They usually produce around 2000 volts at about 2-3 amps. That is what I call "totally lethal voltage". In fact, that is the exact amount of current used in the electric chair for executions in some states!

MOTs are the most dangerous peace of technology you will find in a home. They are very high magnetic flux special transformers that will overheat even when idling and pull a lot of current as well. The secondary is connected only to the core itself and a hot lead which is a deceptively small wire. Also there are filament leads around middle of the core, only 2-3 turns are needed to produce the current for the filament. The amperage produced my MOT even when ballasted or ran at lower voltages is so high that it is very difficult to use for HV applications in a safe way. There are ways but far safer and less heavy alternatives. I recommend most people do not try to use them for anything simply because they are so incredibly dangerous. If you get electrocuted by a MOT, and it would be very easy for mistakes to be made-- there is no hospital and no second chances. IF you did somehow survive, it would be almost like being struck by a urban downed power line, permanent nerve damage and burns.

Many people don't realize just how dangerous these things are, look at a MOT in your mind like it is a pole transformer. The larger ones, if in oil, could handle your home's electrical needs for a time anyway! They are not at all safe for experimentation or high voltage production. Rectified or not, through the primitive single diode half wave converter most microwaves use with those caps or a full wave. Its just very dangerous and take it from me you don't want to take excess risks. I've gotten some very dangerous shocks over the years, but never from a MOT because largely except for a couple of crazy times, I avoided them for such uses. The caps could be useful for some of your work though. I see people being careless with MOTs too often on YouTube. You don't get second chances with them and it's easy to mess up. They also use a LOT of power even if not connected to anything.
-cont.

Gabe W. Beasley said...

I don't mean to preach, but I just wanted to make sure you know. Also building an open microwave gun as some do, adds even more danger, some guys do this and it is very dangerous as well as illegal due to the 900W 2.4Ghz transmitter created.

If you short a MOT to arc it, the amperage is so high a plasma fire can start which can also be very dangerous to your home's electrical system. I have seen this happen. Just be careful, they put out literally 100s of times more current then a flyback, Ignition coil, NST or even large Tesla coil.

A solid state Tesla coil (SSTC) is a great idea. Remember then RF situation you get--burns are common if care is not taken. I have built them myself. Mine could fry a ruler on each end just by arcing to the air! When looking at wave differences you may want other means. Possibly consider building some more traditional Tesla coil as well. There are a great deal of online plans and math resources you can use and that will tell you more about your project. -cont. next comment

Gabe W. Beasley said...

A safer transformer to use-- and one with more voltage to let you work with--is a NEON SIGN transformer. If you can scavenge one of those, 12 or 16,000 volts, you have a 30-60ma high voltage start to a Tesla coil. They can be deadly as well, but are far less likely to be then a MOT. MOTS are also difficult to connect in series and pull way too much power to run Tesla coils realistically. I have only used them under the most serious of controlled circumstances for voltage isolation and high current storage. You can get a good NST on Ebay but be sure you don't get a modern one with GFI, they make pre-made ones already built for Tesla coil construction. I just modified mine by removing it's GFI but that is a bit too hard to explain how to do here. I would then recommend beginning an SSTC but first be sure and learn some of the math about tuned circuits, resonance and inductance. This will help you greatly in building coils. There is no limit to the amount of power, or frequency (basically) you can put into an air core coil. But large voltages and currents are needed for them as they have no core to transmit magnetic flux. Thus, constraint produced by iron or ferrous cores do not apply. No saturation point happens. However, it is very difficult to produce enough power at lower frequencies to see any effect. SSTCs are tricky devices. Most of them operate between 400kc and 4Mhz. I would recommend you look into toroidal transformers. (characteristically donut shaped) Using a toroid, you can produce voltages at very high ranges of frequencies and very low with the same device. This may not be easy to find as many references online, but they are great for high voltage production at verifiable frequencies and schematics are available. If you want to study plasma arcs at different frequencies, the best thing I can think of is a toroid. since it can operate at a very wide range of frequencies as well and offers you a platform that allows for more efficient operation then any ferrous core or air core transformer. You will if a comprehensive study is to be done probably need an air core coil to get the widest range of results. Your pretty much limited to RF with an SSTC, since the mosfets and IGBTs used to drive them don't go much above a few Mhz, many, not above 1. With a ferrite toroid you could wind a very effective broad band coil that could produce a nice arc at frequencies from 100hz all the way up to many Mhz but your drive system will have to be suited to doing so. Anyway, if you have any questions go ahead an email me. I may not get back right away but I will try to soon. I don't post enough of my videos! I recently completed my 200,000 volt x4 series flyback system. I wanted to see if it was possible to push flybacks that far without killing the diodes, and I succeeded with a stable supply but it took a great deal of experimentation and engineering know how. I had to design a way to limit the diode current so that they are not fried. The output arcs loudly up to 18cm or more when I hit the resonant frequencies of my primary windings. IT pulls over 400W! The entire system is now on my YouTube channel "mostlymarcos". --have fun but please me careful, a MOT is like turning your house current back into the power up on the high voltage line that feeds your home!
They are made of special material in order to handle the currents involved. Just look at the primary and size of wire. So few windings makes them real power hogs. I would not hook one up for long and never attempt to short or arc it. Those shown on videos arced are ballasted. You will blow your circuit breaker very quickly as MOTs are a higher current transformer then they looks. They can be used however to make lower voltage by cutting them open and removing the high voltage winding. Then a 2 turn secondary with very large wire makes a great spot welder. --G.Beasley

Unknown said...

Do you have the schematics for the power supply you built? i think the abilitys it has would be of great use to what i want to research.

Also You can email me
Alexander.padgett@gmail.com

Unknown said...

Do you use mosfets to change the frequency