LOOKING FOR OLD TUBE TV SETS--HIGH VOLTAGE--MY GOAL-UPDATED 10-13-2012
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.
THE AWESOME ZVS! (Zero Voltage Switching) driver-->
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.