SERIOUSLY -- DO NOT attempt to work with ANY high voltage device without the supervision of an experienced person. I was nearly killed when I was 10 because I did not have such a person. If you can't read schematics without a cheat sheet, and or if you don't feel you know what you are doing--then you should not be doing it without help! Electricity can KILL. And even the power in this jar-capacitor (above) is enough to kill. High voltage is fun but it is no joke. The many applications it has are great, but it can cause severe burns, permanent nerve damage, and death. I am showing these things for example and demonstration purposes only. I have been working with electronics seriously for over 20 years. I am trained and licensed so I know what I am doing. DO NOT attempt to play with electricity. The field is vast and complicated. So in order to learn you either need to get a good mentor (such as a amateur radio operator), go to school, or both. ESPECIALLY when it comes to high voltage, as things happen with these kinds of voltages that require extra knowledge and understanding. BE CAREFUL. 30 volts can kill under the wrong conditions. If you are a kid getting into electronics, I recommend you start out with a low voltage experiment kit of some kind. Many awesome kits can be found at Radio Shack and as they did for me, will bring you weeks or even years of enjoyment as well as teach you the basics needed to get to a level where you can be safe working with high voltage gear. Remember too--it's not just you. Fire is a serious hazard with nearly any project. And a carelessly left on or plugged in piece of gear can cause serious harm to a child or pet that comes in contact with it. Think about your experiment in depth before you do it and take no unnecessary risks. While it is possible to be self educated in any field, most people including myself need years learning from some kind of teacher to seriously know electronics, it is a very complex and deep subject with many branches. BE CAREFUL! I am not responsible for what anyone does with the ideas or information I post on this blog. Attempt all experiments or projects at your OWN RISK.
My passion for electronics has been with me longer then my serious interest in photography. I have studied it on and off for most of my entire life. This has allowed me to become a licensed Technician class amateur radio operator and build many really awesome devices. This is a dangerous one--It is simple but can produce high current levels at high voltage. Here, at least 50kv, 50,000 volts passes between a jumper lead and the top of this high voltage capacitor I made at home (above picture-blue arcs).
This is the most dangerous experiment I have done in recent times. It is so dangerous I won't post an article on how to complete it on line. I will say put simply, it's a storage capacitor system that again generate a very high voltage for a moment which is also at a very high current level-as many as 20 or 30 amps! So many amps here that the entire thing lights up with sparks for a moment when filmed at high speed. This cannot be seen with the naked human eye.
This is nearly 100kv, or 100,000volts. If you ever wondered what it would look like to arc an x-ray tube transformer--this is more or less it. The arc here is about 70mm or 7cm long but it will begin to arc before that. My largest arc from this HV supply was 12cm. That's at LEAST 120kv (120,000volts). I developed this just for fun because I saw way too many small arcs out there! I wanted to build my version of the ultimate ZVS and also build one that could handle 2 flybacks in series without oil. I succeeded! It's fun to impress friends and relatives with this intimidating spark. I plan to try to make my own plasma displays. And it may soon be the largest "singing arc" I have ever seen! I use it mainly as a sort of beginning run for my future Tesla coil and for making interesting and amazing arcs as well as lighting florescent lights several feet away--people are really amazed by this. I always wanted that old "mad-scientist" movie look to some of my pictures--I can finally do that with an ark that looks really cool and will make a heck of a Jacobs ladder as well. There are things to consider however--arcing high voltage can produce Ozone gas which stinks but is not toxic. Also, it produces LOTS of EM. It would be illegal to hook an antenna of any kind to this device since that would make it a spark-gap transmitter. Even small arcs create broad-band transmissions that can cause serious interference with aircraft navigation and other things. If you live near an airport, you may not be able to build or work with Tesla coils unless you have a Faraday cage to put the arc and it's components in. Take care in construction and perform tests to make sure it does not cause problems with TV/radio.
Very high voltage can be roughly measured in a simple way. When an arc begins between two points for every 1mm reached the arc has about 1000 volts or 1kv. This however only tells you roughly how many volts you have. So if you have an ark this size, say it starts "cracking" at 75cm--you for sure have at least 75,000 volts. Many stun-gun companies have made outrages claims about voltage that I put to the test. In recent years they have come up with new designs to reduce "kickback". This required reducing the voltage. That is actually not a problem at all, since the good models traded voltage for current. However they did not want to say that the new models were less volts then the old ones! So they usually lie, and thus many stun-gun companies (Not TASERS) claim to be capable of "millions" of volts. This was just a ploy to make them sound more powerful. My tests showed they range from 30-60kv. Most quality models are around 50kv just like a police TASER. Police should not be overly afraid of these devices as shown on some police shows--the TASER they probably carry is almost certainly more powerful then even a "7 million volt" stun gun". Electricity is about the CURRENT (measured in amps and milliamps), how many milliamps (ma) the electricity is at. You can get over 100kv from a blanket! However, it won't even knock you down. This is because the amperage, the current, is very very low. It's a bit like a small fire-hose and a pressure water gun. Both may shoot water just as far, but the fire hose pushes 100s of times more water out then the water gun. I used to have a stun-gun that definitely approached 100kv but I cannot find them anymore. This does not mean it will be less effective, as the 40-50kv has far more "knock down power" if done right--then the old higher voltage models that would not only shock an attacker but shock you as well! Most of the new ones are built better. Generally on line, you get what you pay for if you go to a Stun-gun site. Kickback through the batteries, switches and even plastic is why the voltage had to be lowered--the ones that are really high often would shock the person using it at the same time as the attacker, not as much, but this still rendered it nearly useless.. I doubt you could build a useful 200,000 volt stun-gun. It is just not piratical to build something that produces 100,000 volts or more in a very small package! Most people are under the false assumption that voltage is what hurts and can kill. Current and frequency are two other very important factors, the most important being current (ma). A similar "kickback" situation happens with this ZVS I built. The high voltage goes back into the DC supply which thankfully arks to the metal chassis and close wires rather then totaling parts and destroying itself. But this is not good, if your ZVS has arcs you don't want, you need to fix it or parts will fail far faster. This ZVS definitely pushes the limits of TV flyback technology. It is not possible for me to earth ground it despite a large series of MOVs and snubbers. It seems to be impossible to ground TV flybacks tied in series without overloading the entire system if it is a ZVS. A recent test damaged this unit when I was making arcs. I was able to repair it, but I will not try ground it again! The voltage jumped so high it arced into the primary insulation in about a second. It was rated for hundreds of volts. I hoped that if I could ground the DC low voltage and the HV things would be stable, but as with my 555-Mosfet system--the voltage output increases with an Earth ground (that is good and has a different effect for the 555-mosfet system--more power and almost no kickback!). Interestingly, the 555-mostfet system actually had to be earth grounded if I did not run it off batteries. Where the ZVS can't be as it is a two phase resonant circuit (I use the term "phase" loosely here as a pulsed DC term). Two mosfets power each side of the same primary coil with a center tap in a basically "push-pull" cycle. The 555-mosfet system has only 1 line to the coil other then the ground, one phase to one side of the primary and the other to ground.. This makes it possible to earth ground it nicely, including AC/DC flybacks. However 555-mosfet systems can get hot very quickly and are not as efficient as ZVS systems. The single phase synthetic aspect of it makes it very stable when grounded to earth with a 3 prong outlet. This lets it run ignition coils and just about any kind of transformer without kickback problems! There is never any kickback noticeable, even when drawing large arcs! I am working on a way to build a 555 driven dual flyback system. I already have done it, but with just 1 mosfet running both flybacks the voltage gain was only about 10kv over the max output of 1 flyback--not worth it. I am almost sure the flybacks will have to be in oil if I really get it going, say with more mosfets. With the ZVS, no matter what I do, some of the power arcs back into the cores of the flybacks and wires. The only way to keep a TV flyback ZVS stable is to power it off batteries or not ground any part of the HV or low volt DC while I keep things balanced with insulation. I also cannot hook it to any large objects that would become a floating ground themselves.
(More pictures coming soon)
I am trying to overcome these problems to find the best supply for powering a 300-500kv+ Tesla coil I plan to build when I can afford it. Generating voltages this high is a complex science with many problems to solve that are very similar to radio frequency devices. Putting the flybacks in mineral oil may allow them to become more stable but I doubt it would solve the problem of kickback totally. If you build a flyback system or ZVS of any kind understand that your dealing with far more complex factors then low voltages. The voltages produced may also exceed what the flyback diodes can handle and destroy them that way. A flyback I was using died from the overload so I since refuse to remove the (50W) 12V car headlight (you can use halogen bulbs or 12V 50W bulbs from nearly many stores) to protect the circuit components and also give a visual warning if something is overloaded. Since this ZVS system runs on 22 or 44DC volts--a dead short may blow the bulb like a fuse--but that is far better then blowing both mosfets! It took me days of experimentation just to figure out how to modify the ZVS to work with 2 flybacks and solve the problems. I was compelled to figure it out as I read on line that it was "impossible" to connect DC flybacks in series and so I wanted to prove them wrong and get more real-world experience before I start on the Tesla coil which is my current goal for all this high voltage stuff. For Example, I had to completely coat the bottom of them with hot-glue so that the 2nd flyback does not arc. Don't arc a ZVS like this for a long time. As I say I also recommend always using one or two 50W 12v light bulbs in parallel to protect your mosfets should anything go wrong, this also acts as a second fuse and trust me, saves you lots of money in parts while cutting down very little on actual output. If you don't--if one mosfet goes it will short and probably fry, taking the other mosfet and possibly other parts with it! You can also see your current draw by how much the light bulbs light-which should not be very much. A quick way to know something is wrong and what might be wrong. I also have a fuse on the 120vac mains--this is VERY important. If you don't use a ballast bulb like 12v 50w bulbs-- you will blow a lot of parts before you get it right! I bought a pack of 3 at a Safeway store for less then $10 and now use them in all my HV supply experiments. I also use current limit resistors to further keep things cool and not overloaded. The large power mosfets (IRFP250) do not get very hot so only small heat syncs are needed. This is a great supply for plasma experiments and amazing your friends as well as getting photos of awesome arcs and there effects. Smaller versions could power lasers and other very difficult and advanced projects. I can adjust it from about 20kv to nearly 100kv with 4 different settings on the DC supply that I built to power it. It costs about $400-500 to buy a supply that can do the same thing on line. I can't afford that. Being a licensed amateur radio operator and an amateur scientist, it has been a lot of fun since I have been seriously interested in electronics for more then 20 years. Of all the 100s of projects I have built, this is surely one of the most interesting and fun.
IT CAN BE DONE--like an article said somewhere you can't hook 2 flybacks in series, I also found one that said you can't build your own flyback! I challenged that too. I built a flyback. It's not quite as powerful as most TV flybacks, but it's AC output makes it great for arcs and plasma displays. The above picture is what NOT to do! This was an early attempt I tried to show why you can't just lump on wire. Sloppy coils might work to some degree in mineral oil, but messy windings don't work well and enameled wire has no insulation to high voltage so immediately it will start arching to itself in a normal environment. I never found out what this transformer could put out. So I re-cycled the ferrite core and wound one the right way. To prevent internal arcing you put layer upon layer, each wound the same direction and in the same way. After each layer you lay the wire across and make the next winding with a layer of electrical tape or better. Use double sided tape to keep tiny magnet wire neat and stick to the coil. It takes time, and concentration but it can be done. Laminate each layer with Teflon non-conductive tape or electrical tape, 1 or even 2 layers. Put as many turns down as you can at first--then work your way up. This one has about 12 layers. Starting at about 30-40 turns the last layer only has about 15-20 turns. Each one has a few less and is covered entirely with tape so that arcing is prevented. BE SURE to use some double sided scotch tape or folded scotch tape to stretch across where you wind each layer and wind it tightly. This will give you an edge when winding by hand very small wire. It won't come lose as easy and it will be far more easy to guide the wire on as it will stick to the tape and stay in one place. If you do it right and you have big enough core--you could build a very large flyback this way. Possibly up to 50kv or more! However, it may take 30-40 layers for that many volts. Just as long as the insulation is good enough--to go higher then some voltages you need to submerge the coil in mineral oil.
Be sure each winding has a cover of electrical tape that totally covers it up. All the way to the side. This stacks them like batteries, so they won't arc to each other. Then you just have to use hot glue to make sure the ground (which will be the inside lead which is the first wire from the bottom winding) and the hot lead--don't come too close to each other or the core. Of course wind you coil around a plastic tube that fits into your flyback core. This could be a chapstick container or something. It is critical to insulate the coil from the core to prevent arks. I used the core of a dead TV flyback I had. The core comes apart easy but be careful as they are about as fragile as glass and too much knocking or even force can cause them to crack to peaces. When done, replace the metal bar or just use tape to secure it and hot-glue the rest. Hot glue does not even show conductive effects at 100kv! I have found it invaluable in working with high voltage projects. Here I had not even finished putting a HV line on it yet, your ground lead can be any old trustworthy wire--and for an AC flyback should be grounded to your power supply and Earth ground if you have a 3 prong outlet and are running on AC power. The upper hot lead then should be hot-glued carefully and securely somewhere on top of the last winding--that's the one with the most HV--so it won't arc. I chose right in the middle. Cover it all in hot glue and it will be insulated. Then use hot glue to keep the tape in place and from possibly arcing out of the last few windings. DO NOT connect the core to ground or HV. And use a HV wire rated for the voltage you think your flyback is. It's best to go high--such as good ignition cable or other HV cable. This way you won't have problems with possible burns through the wire. The core should float since any potential might cause arks to fly out of the sides of the coil if you don't have enough tape and hot glue. No enameled wire should be exposed, and pay close attention to the winding process. All coils must go the same direction and NOT back and forth, just one way. Right or left every time on every layer. Then I used some good wire that can handle high voltage for my high voltage output. For this small one, my first one, I only needed 15kv--but I still get leakage. So I should have used full 20kv cable or more. Ignition cable is great for this too. This is a simple idea but it's difficult to get done. They used to layer flybacks like this back in the 1950s and dip each layer in an insulating solution. Tape and hot-glue will work fine.
I had a Russian Magic eye tube that did not work :( Magic eye tubes are small tubes that used to be used in radios and audio gear to show tuning. They glow green and work just like a tiny CRT. Phosphors convert low power cathode rays into light. The filament no longer would heat up in this one so I thought what the heck do I have to lose? I hooked it up cold cathode and to my amazement it came on almost as good as if it were being ran with a hot cathode and all the right connections! It was also just as bright. I was amazed that I could even get it to respond, although not as well, to the grid. It definitely works this way. I really did not think I could get a magic eye to work cold cathode!
A SERIOUS NOTE HERE ON X-RAYS and high voltage in vacuum and radio tubes: At voltages below 15kv X-ray radiation is not really a worry since any produced will be high UV or "soft" x-rays and probably unable to even penetrate the glass of the tube. HOWEVER at only 20kv you run the risk of producing DANGEROUS X-RAYS. And don't get any ideas, they are NOT enough to take pictures or expose film. Such experiments are extremely dangerous and I have seen too many fools try to do this, it ends in a wasted effort, fried tube and possibly worse. NEVER attempt to produce X-rays or operate tubes that are marked as x-ray producing tubes. Without the right and very complex specific shielding you will get very sick, burned or even cancer. Look on line for what these burns do! I bought a Geiger counter as part of my gear to make sure none of my experiments generate dangerous levels of x-rays or dangerous radiation (ionizing radiation). This is a good idea for anyone working with tubes, tube lasers and high voltage for any reason. Even though I knew I was only at about 8kv with this tube, I checked with my RADEX Geiger counter. But since this type of tube is probably not lead glass and most radio tubes are not, I wanted to be sure. Be aware that when working with many flybacks and tubes if you try putting high voltage directly into them for any reason. If you are using a tube HV rectifier, make sure it's in tolerances and check for radiation. If you detect any--you should stop using the tube immediately! Never arc high voltage into vacuum tubes or radio tubes. This leads to fast and permanent damage to the tube and could be very dangerous. Tubes are rare, most are not made anymore, you should never waste them. And high voltages in flybacks will blow up filaments and destroy grids. It does not look cool and it happens very fast, just an instant dead tube. I once tried to use an old radio type 76 as a plasma display tube, and found nothing happened except an arc bit right through the glass and shocked me! Today that tube would be worth $20! They are usually not designed to handle more then a couple hundred volts. Not only that, the filament was ruined and the tube was now filled with regular air. The same thing happened to me with DC fly-backs and florescent light bulbs and other small potential arc-display tubes. You can't make a plasma a display out of a vacuum tube- what goes on would not be visible human eyes so no "cool" video either! NEON and other gas regulator tubes make great and safe plasma displays however--be sure to use a large resistor (1-2meg) as a current limit (then just wrap the high voltage wire onto the tube and often they will light up). Some people mistake old TV rectifier tubes for "X-ray tubes" as there is a warning on them. They are actually made of lead doped glass and do produce a small amount of rays so often they are shielded inside the TV. Not enough to expose film--just be dangerous if you spend too much time near them. This is why your mom said don't sit too close to the TV (if your old enough to remember that)! If you are using tubes with high voltage for whatever reason--it is important to be aware of possible x-ray issues and it's a good idea to get a Geiger counter (no mater how rare or unlikely it's good to be sure). Although expensive ($170+)--they are always a good peace of gear to have and know how to use (this takes some learning) in your home lab. Most plasma displays and nitrogen filled light-bulbs, mercury vapor lights & florescent bulbs or neon bulbs generally do not produce harmful x-rays. It never hurts to test every type of plasma display and tube you use--if you pick something up DON'T USE IT. Keep your counter a foot or two away from the source to prevent false readings from HV.
EM SERIOUS NOTE: As I already mentioned, arcs and high voltages produce RF energy in the EM spectrum. This is not dangerous to people--except if you touch the hot lead of an AC flyback and feel an RF burn! HOWEVER it can be very dangerous to passing aircraft and other services. I know some people would love to make a spark gap transmitter. :( I would like to be able to build the same radio set from the days of Titanic--but as far as transmitters go, spark gap transmitters put out too many frequencies to be filtered and thus were quickly outlawed everywhere back in the 1920s when tube oscillators replaced them as a means for far more conversations to take place at once and the use of higher frequencies. We must respect the electromagnetic spectrum as these arcs can cause massive interference on TVs and other devices. I live in an area where someone's ionic-air filter (that's my best guess) makes working 10meters almost impossible! This is very irritating and technically illegal. I don't know where they are, but that's my guess what it is since it's on most of the time. Many of those produce small arcs and harmonics over a very wide bandwidth that sounds like noise. Never put an antenna on a arc or spark gap and keep leads to them short. Spark gap transmitters might look cool but there are plenty of other ways to make awesome projects and transmit clean signals legally. Aircraft use many AM and low frequency systems that could be seriously effected by spark gaps if your arc is connected wrong. Always be aware of how much electrical and other interference you may be putting out. You don't want to jam up everybody's TV/radio even in a digital age this happens. The FCC will break down your door if you mess up an aircraft Nav. beckon signal. Don't put long leads on stuff that will arc and take care when experimenting and test for all forms of emissions you might suspect could be a problem, use a shortwave all band radio and an EMF meter to see how much energy you are giving off and how far it can travel. Proper tests are very important if you are going to experiment with electronics and other devices.
HIGH VOLTAGE CAN KILL! If you have a pacemaker you should NOT experiment with ANY of these devices or high voltage as it may be disrupted. ALSO flyback transformers can be very dangerous but probably will just give you a very painful shock or burn. NEON SIGN transformers and microwave oven transformer have there uses but they don't give you a seconded chance to remember that pain! A NST or MOT can kill a young man in good health instantly! BE EXTREMELY CAREFUL when working with high voltage and always unplug when not in use or working. Be very aware of capacitors--as they can also be deadly. Even a camera flash can hold enough of a charge to kill if it is big enough. I once blew a 100W light bulb with a capacitor from a medium camera flash. And I nearly died when I was only 9 years old doing my first experiments in electronics without knowing many of the basics. I got myself hooked to a 600 volt transformer that was inside an old electric fence system. It produced enough ma to kill someone! The fence itself used a buildup in a capacitor oscillator circuit to produce a higher voltage in pulses which made it safer. The 60hz direct output threw me across a room and left me unconscious for over 1min. I could not even move. It took me a day to recover. I was lucky because a friend pulled the plug, otherwise I'd have been killed due to a strange effect called being "hooked" when a charge at a lower frequency holds your body by moving your muscles (which are electric that's why they move when shocked--we all are powered by electricity!) Electricity is dangerous--just because a transformer is small and looks safe or low voltage does not mean anything. Be sure to be thorough about your work and tests to insure you live long enough to have fun experimenting! --or just sit back and look at my pictures. :)
(Image removed--really bad quality need to re-shoot--plans will be back soon with brighter images)