HV capacitor leakage? Answered

I have just built a high voltage glass capacitor for my Tesla coil at a 0.03uF 50KV rating and I have found that the leakage is quite high, the stored energy is almost completely gone in 15 seconds does anyone know how to resolve this?

Question by The MadScientist   |  last reply


???BBQ grill igniters???

All the outputs are labeled positive and arc to each other(very confusing)

Question by AlbinoMoose308   |  last reply


Charging HV capacitor banks

I noticed that recently a lot of users are looking on information on how to charge capacitor banks. Not going into the legal aspects here when it comes to coil guns, EMP's and similar applications... I do have a few options at my disposal depending on how fast the charging needs to be but for serious applications with high power levels, fast charge rates and so on it soon becomes very technical. The differences between the US mains power and the rest of the modern world only complicates things here. So I was wondering who already build some decent cap charger based on inverter technology and if these people are willing to share their info and schematics for reference - if you already have an instructable explaining it a link to it would help heaps. Considering the costs of high performance caps circuits with proper protection against overvoltage and with good current limiting properties would be prefered over simple circuits that could damage the caps. Thanks for your help!

Topic by Downunder35m 


Can I modify an electric gas lighter to charge to charge HV capacitors?

I need help for charging High voltage capacitors. I have an electric gas lighter and I require help to modify it so that I can charge High voltage capacitors for coilgun using it.Please help me.Thanx in advance

Question by Jayvis Vineet Gonsalves   |  last reply


Beer bottle capacitors? Answered

What is the average capacitance of a salt water beer bottle capacitor?

Question by The MadScientist   |  last reply


Microwave capacitors? Answered

Is it possible to put 25 microwave capacitors (2kv 1uF) in series and running 40kv through it without them failing?

Question by The MadScientist   |  last reply


Solid state Tesla coil circuit? Answered

In this SSTC circuit from Uzzors2K I am a bit confused were the 12V and ground actually connect to seeing that this is a AC circuit? Also seeing as the AC is immediately rectified (I think you can do it with a bridge rectifier) is it possible to power it off DC?

Question by The MadScientist   |  last reply



Frequency driver HV generator circuit Answered

Dear all... At this circuit please help me to know: - How many cycle (frequency)and duty cycle : time high and low  (percent) for  better driver this circuit. Sorry for more question.If I change other transformer (ferrite core)and driver by 555 timer, frequency  and duty cycle must   be modifier or not ?                                      Thank you in advance

Question by lam   |  last reply


Please give me a simple schematic for charging a HV capacitor for a coilgun

In India you don't get disposable cameras. Could you please give me a simple schematic for charging HV capacitors. I really wanna make a coilgun. THANKS IN ADVANCE!!

Question by Jayvis Vineet Gonsalves   |  last reply


How do I determine the primary turns needed for this PLL solid state Tesla coil? Answered

I have nearly completed my SSTC but I am unsure how many primary turns are needed, is it just an educated guess, or is it calculated? There are no specifics on this on the website http://uzzors2k.4hv.org/index.php?page=pllsstc1.

Question by The MadScientist   |  last reply


Would the HV source of a crackle plate work to charge a bank of HV capacitors?

My cousin has an old Crackle plate, like those funky sci-fi glass plates that have lighting that looks like electricity flowing through it, like you get at Spencer's. The edge of the glass broke, and I was wondering if I could use the HV source to charge a bank of electrolytic capacitors for a Marx bank.

Question by m0nk3yb01   |  last reply


HV power supply and ZVS switching? Answered

I am slightly running out of brain power here and get the feeling I am just running around in circles. Problem: I want to build a HV power supply delivering 10-15KV that is driven by a ZVS circuit - basically the same I used in my Induction Heating Ible. I also want to double the output voltage with a simple cascade. Goal: To get the most effiency without overheating things. Areas where my brain feels too empty from thinking: 1. I know for sure the primary of the transformer will operate at a resonant frequency but how does this affect the scendary coil, especially under load? My small scale tests showed quite severe changes in the frequency depending on the load put onto the primary... Also the output voltage shows "spikes" at certain frequencies, I assume this happens while both primary and secondary share some harmonic frequencies. 2. With a simple dide/capacitor cascade I would only get a DC output, to keep an AC output slightly more complex circuits are required. How does this affect the resonant frequency of the secondary winding? 3. Considering 1 and 2, is there a simple way of keeping both the primary and the secondary coil of the transformer in resonance regardless of the load?

Question by Downunder35m   |  last reply


how do you measure HV?

What's the best way to measure High voltage (I think my output is somewhere between 10kv and 50 kv)? Is there a formula for the spark length and humidity (I can measure humidity)? I need to buy an appropriate capacitor for my tesla coil, my initial HV is from an ignition coil.

Topic by guyfrom7up   |  last reply


HV capacitor bank charge indicator?

Hello! I have a capacitor bank with three 330v capacitors (from disposable cameras, of course... those things are awesome) connected in parallel, but I'm planning to add more. I'd like to indicate when the device has been charged using an LED, but I'm pretty sure that most LEDs can't handle 330v. The disposable cameras often have indicator lights, so how do they do it, and how can I implement it with more capacitors?

Topic by SirCheez   |  last reply


I have a three phase power point in my room (500V, 20A, 50Hz ) whats some cool stuff I can make and plug into it?

Preferably something I can make cheep. I have some experiance with electronics(3rd year optoelectronics at uni) but no experience with much more than 1A and 30V circuits.

Question by    |  last reply


SMPS H-Bridge trouble

Hi,  I've built a 1kW SMPS designed to take a 350V unsmoothed DC input and convert it to 3kV @ 300mA. The circuit is basically Uzzors2k's design seen here minus the overcurrent protection and smoothing capacitor (for now), however I accidentally wired the GDT outputs backwards so the gate resistors (33ohm 2W) are on the source. I have used alternate MOSFETs the latest attempt with FDPF16N50T's. I've had various problems with the circuit, primarily the MOSFET's exploding seemingly from overvoltage (evidence of flashover in some cases despite no evidence of secondary leakage (i dismantled the transformer to check)). During my last test I had a flashover between the drain and source pins of one of the FET's, in addition all of the gate resistors were smoking hot after, seems the gates had all been shorted (first time this happened, other occurrences were from case to ground). This happened despite the variac only being turned up to 40% which should be well well below the pin spacings maximum voltage tolerance. I have checked the drive signals, they are quite nice square waves at about +-15V with some oscillation on their rise. I have built SMPS's before, one is currently working with similar MOSFETs using a half bridge at 300W. Does anyone have any suggestions as to why these troubles are occurring or have any suggestions to fix it or have any alternative circuits that may be less troublesome (is a h-bridge easier to manage?)? Thanks, Stephen I​ just gave it another test with a H-bridge instead and the source of one of the FET's blew so it appears that there is just FET failure and maybe not arcing between drain and source.

Question by The MadScientist   |  last reply



Can you tell me how to find out the hv pin and the primary coil (input) pins from a flyback and the polarity of input ? Answered

I found a site from an instuctable (http://lifters.online.fr/lifters/labhvps/tht.htm) but it doesn't work. I have two transformers one is old from a TV and the other is new from an monitor, from that site I find out the primary and hv negative for the old one but i didn't find out the polarity of the primary coil pins. At the new one the methods from the site didnt work. please help me.

Question by theVader75   |  last reply


Possible to hack a NST with sGFI?

I'm having a really hard time finding an old neon sign transformer (NST) for high voltage (HV) experiments. Almost everything on craigslist is of the newer transformer that has the secondary ground fault protection.  So is there a way to hack the new ones?  I appreciate and thank you in advance for your help.

Question by JeffB23   |  last reply


In an AC SG Tesla coil circuit can the capacitor be half of what it should be?

AC SG Tesla coils usually have a HV AC transformer leading to a capacitor. The capacitor is usually tuned to the transformer so the spark gap will fire twice a cycle at every polarity change due to the 50-60Hz mains frequency.  Can you match up the transformer to capacitor so the spark gap will fire four times every cycle instead of two and will this still produce good results compared to the conventional method?

Question by The MadScientist 


Flyback transformer broke in two days Answered

Hi, I made a flyback driver from a 555 timer 2 days ago and now its not working. I think the flyback broke but i dont know. I ran the driver with 6 volts at first but got tired of the 1 cm sparks so I used 12 volts instead and it stopped working. I left it alone for a while, and when i tested it again, it worked again. Now its not working again and i think the flyback broke this time but im not sure.

Question by joeismydad   |  last reply


How to test N channel mosfets? Answered

Hello, i built a ZVS driver about an year ago. I used to power it from a computer power supply at 12v ,than i changed the power supply to 30v and 10a.With the new power supply it worked as well for about 3 moths. A week ago a wire got burnt and a zenner diode. I wanted to test the mosfets too but he tests i searched on google didnt work. Please tell me a good method to see if my mosfets are burnt or not .

Question by theVader75   |  last reply


How to make a lightweight 10kv 500 watt power supply?

I need to convert up to 500 watts of 12 volt to at least 10 kv. It's important that it has both +10kv and -10kv. Right now I'm thinking flyback converter driven by a 555 to 1000 volts then voltage multiplier to 16kv. It's important that it's light so I don't want a regular flyback transformer. I'm wondering how duty cycle effects a transformer. Does it effect it like it would with an inductor-based boost converter? If so, then according to this calculator http://www.ladyada.net/library/diyboostcalc.html I would need an 88% (88% high?) duty cycle to get 12 volts up to 100 volts with a boost converter. Does this mean with a 1-10 transformer I could get 1000 volts from 12 volts with an 88% duty cycle? If so, then I need a light weight 1-10 transformer. I'm thinking winding a toroidal transformer will be best? So I could get a ferrite toroid (I'm thinking material 61, size 114) and wind a 1-10 transformer, but I need to make sure it doesn't saturate. Do I find out the saturation just like I would an inductor in a boost converter? If so, then according to the same calculator, the higher the output current, the less henries I need. So that means if I don't draw enough power it will saturate? I'm probably going to use 25 khz, so according the the calculator, if it's 100 watts then I need a little over a 25 henry primary. But if I use 500 watts, then I only need a little over 5 henries? This doesn't seem right. Soooo according to this toroid winding calculator http://www.66pacific.com/calculators/toroid_calc.aspx with a material 61, size 114 toroid, I would need 2 primary turns if it was drawing a minimum of 100 watts (the lower inductance/higher current can't be right can it?) and then I would need 200 turns. Sooo my question are (haha) is this a good idea for a light weight high power hv power supply, if so are the similarities I'm assuming between boost and flyback converter correct, and if so, how many/how do I figure out how many windings I would need on each side of a toroidal transformer/ how do I figure out what inductance I need for the primary. I have pretty good experience making boost converters but I've never made anything hv. Very long question thank you this is for an ion thruster.   

Question by sk8aseth   |  last reply


Can someone make sure I made this HV power supply right?

So I'm making an HV power supply from a flyback transformer and a CFL, I need to know that I've wired everythng correctly, and I'm not going to kill everything plugged into the walls in my house when I turn it on. From left to right is: Socket, IEC13 (From an old computer power supply) Switch, rated for mains voltage (from old CRT TV) CFL circuit Flyback Blue wire is the live and brown is neutral, the red and black connect to the primary coil of the flyback. All help appreciated, thanks.

Question by Pie Ninja   |  last reply


Should I use it? Answered

I got this flyback transformer without high voltage cable so I cut it until I found a tiny piece of metal. Is it safe to use the transformer ? and If it is how do I find the best coils to be the primary and the feedback from the 2n2055 driver.

Question by theVader75   |  last reply


high voltage from a large flyback transformer? Answered

For the life of me i cannot get big spark gaps from my flyback transformer. I did all the steps to find all the pins and i have a 600v electronic instant on ballast. Im using clothes hangers for the wires the arc climbs up and it is attatched to a laminated particle board. I need to have the wires really close to eachother for it to arc, but then it just arcs up and down about 1/4" if that.. ive tried positioning them all sorts of ways to try to get it to climb but nothing... i feel like the fbt should be putting out massive amounts of power but its not it isnt even getting warm when i turn it on...even left it on for a bit and no heat! Ive tried a couple different pins for the HV- And the one its on gets the biggest arc..is it because its on wood? If so what should i use? Or is it the clothes hangers? No idea but any advise would really help me out.

Question by sjameson1234   |  last reply


How to improve tesla coil ? Answered

I built a tesla coil, but the output is just a little spark barely visible when i approach a screwdriver to it. primary is 5 turns secondary 500t capacitor is made from 2 layden jars spark gap is about 3mm the coil is about 15cm tall the power supply is a flyback transformer driven by the zvs at 12v What do I have to do to improve it?

Question by theVader75   |  last reply


how to convert High Voltage DC into AC without changing Voltage? DO CAPACITORS WORK ON HIGH FREQUENCY CURRENT? Answered

I want to build a Spark Gap Tesla Coil but the problem is that I am unable to find a neon sign transformer locally. so i decided to a voltage multiplier. But its output is DC which means that Capacitors (most probably) not work. so please can you tell me how to convert dc to ac without changing its voltage. ALSO, I was wondering whether a capacitor will work with high frequency flyback transformers or not. ????????????????????????????????

Question by SHREYANSH_HV   |  last reply


Help application note on for High voltage supply of 12kv, 6kv from 24V AC, 50

Dear forum members. I am looking for HV multiplier circuit that accept 24V AC, 50 Hz and convert it to two HV outputs 1) 6KV , 2 mA 2) 12 KV , 2mA Can anybody have such application details, or made by themselves, or any app note reference. OR anyone had instructables on this site. Please give me such details on my email id "bdmehta@yahooo.com Regards, Bharatkumar

Topic by bdmehta 


I make the rwilsford07 DC-DC HV Boost Converter and it only gives 32 volts

I want to build the DC-DC HV Boost Converter but it only gives 32 volts from a 9volt input. The output voltage depends on the number of oscillations? I am using coilcraft PCV2-394-05L and the mosfet 75N75

Question by Kurt Gerhard   |  last reply



What determines the max output of a Nitrogen TEA laser?

I was thinking about building a TEA laser, using nitrogen from the air. Like many others, I want it to have a really high (peak) output level (high enough to ionise air). What's the limiting factor for the amount of power I can put into it? Does the air "saturate" or something when there's too much current going between the electrodes? How come you can't connect it directly to the HV power source, but you have to have a spark gap/capacitor to fire it? So would it work on AC? Thanks

Question by .Unknown.   |  last reply


How to pick out a transistor? What I should look for? Answered

I need a MOSFET transistor for a flyback transformer driver. Many guys said 2n3055 and I want another. How can I compare?or can you give me a list of transistors that I can use?

Question by theVader75   |  last reply


How to make laser-induced plasma? Answered

Hi, I was wondering how I could possibly make a small version of laser-induced plasma. I understand there would probably be high voltage as well as precise electronics required, but I'm quite confused by what I've found online. I would just like a simple explanation and/or a theory. Thanks! Cheers,    Laser

Question by Laserbeamtoast   |  last reply


Ideas for creating a portable Tesla coil

I am in the process of planning a small-ish Tesla coil that can fit inside of a medium-sized hard shell suitcase. I would like to be able to power it without using a wall outlet, which most likely means with 6v lantern batteries or 12v lawnmower batteries, but if you have any other suggestions I'd be glad to hear them. I would prefer to keep the coil as simple as possible and maintain a spark gap configuration rather than a solid-state one because I am not very good at soldering small parts. I was thinking about using a neon transformer from a set of car under lights such as these http://www.amazing1.com/profneon.htm (is there anything there which would work especially well?) or perhaps a modified ignition coil with a mechanical interrupter, similar to a Ruhmkorff coil (I have no idea how I would do this, but it sounds like it would work). Your thoughts? Also, instructions on how to construct a flat 'pancake-style' secondary could be beneficial.

Question by Justin the Red   |  last reply


High voltage discharge capacitor help?

I recently got a 50uf 2000 volt polarized pulse discharge capacitor to blow stuff up. I tried to charge it with a microwave transformer rectified by a single HV diode, but that did not work. My plan was to fire up the microwave transformer, close HV switch #1 to charge the cap, open HV switch #1, and turn off the microwave transformer. Then I would close HV switch #2, and would send power to "load", in this case an orange (see diagram). However, when I closed HV switch #1 (which is a nail in a piece of wood and a rod on a PVC pipe), I would get arcs. Then, when I closed HV switch #2, nothing happened. I even tried shorting the cap with a rod, but it had not charged. Before this test, I tested the capacitor by charging it to 120 volts and it worked fine (I got a spark). Also, there is no internal resistor to discarge the capacitor after a long period of time. Should I try a full bridge rectifier with 4 diodes instead of a single diode? I will also include a schematic of the circuit (you might have to zoom in in order to see it).

Question by TimTD   |  last reply


Stun Gun Mod Suggestions/Tips? HV Power!

The 2 images are the type of stun gun parts I have, I believe its a spark gap igniter one but m not 100% on that as I would rather leave it in the cardboard circular case unless I get confirmation it could be modified. What kinds of projects could this be used for, I'm pretty sure its DC powered and attempted putting the outputs to curved metal electrodes for a Jacobs ladder but arc stays in one spot after many adjustments.  Ive only worked with HVAC with an unrectified flyback for plasma globes. Anyone have any suggestions on what to pump this badboy into. P.S. Using 2 metal screws from an Xbox 360 and putting them very close together makes a very nice whistle to it, :).

Topic by thebellbell 


can a tesla coil be rectified with a huge diode? Answered

I found a few hv diode (1 Mega Volt) and some around 240 kv, but the question that I asked myself was if I could get  DC current from a Tesla coil by rectifying it with a proper HV diode. Is it possible???

Question by arenavles   |  last reply


How do i change a 18v 1.5A DC cordless drill battery to AC? (in other words, how do i change dc to ac ?)

I need a high voltage power supply to power a tesla coil from a battery, and i need ac not dc, so if i can change my battery to ac then i can run it through transformers to get HV AC power to run my tesla coil.

Question by lightning r fun   |  last reply


voltage multiplier for flourecent tube driver?

I have a flouro tube driver from an old scanner, when i put 12v dc it i get a nice tiny spark across the output wires now i want to make the spark BIGGER how could i do it with not many parts?

Question by The nerdling   |  last reply


How can I select part of PCB? Answered

I have 2 PCB that I want to select the essential from them. The PCBs are from a CRT monitor and the other CRT TV so I tested out the TV main PCB and the FBT gave strong arcs but I want to select just the driver.  Or how to find the schematic of the tv or monitor

Question by theVader75   |  last reply


How do I make the dc only portion of a strobe light? I already have a trigger.

How do I go about making a simple 120vac to 300vdc power supply? I am making a strobe light and gave a trigger set up but I need a way of getting the darn thing to light. PLEASE HELP. Is there any way to use my function generator to replace the trigger?

Question by professorred   |  last reply


How to power tesla coil? Answered

I asked a similar question https://www.instructables.com/answers/How-to-improve-tesla-coil-/ and I still didn't managed to get a spark. I want the simplest way to build and power this tesla coil  Now I have : -5 layden jars -1 MMC -1 primary 5t -1sec 500t -1 zvs (dc out at 30kv) -1 ignition coil -5 timers -1 MOT -2 capacitors for MOT at 0.98uF -2 diodes for MOT

Question by theVader75   |  last reply


Im trying to find the 0v HV pinout of my flyback yet i dont have access to an ohm/ voltage meter.I dont know what to do Answered

. the model is a sampo FEC061 pulled from an old toshiba CRT monitor. thanks greatly to any one who can help it is much appreciated.

Question by blacjack1   |  last reply


electronic ballast flyback driver...can i wind the wires around the primary of the flyback?

I have a electronic ballast and a flyback . I am having problems finding the primary coil pins of FBT because i dont have a multimeter. so i was just thinking that can i wind two ballast Vout wire around the flyback primary (the metallic structure , or whatever you call it) there are total 6 wires on the E-ballast. two are for input and 4 for output. the output wires are in sets of grey and white wires.  I was thinking that i will take one grey wire and wind it around the fbt primary(metal thing) and then connect it back to white wire. is this correct? also can i wound a feedback coil from the other 2 wires? PLEASE ANSWER....................ANY HELP WILL BE APPRECIATED. : )

Question by SHREYANSH_HV   |  last reply


what is the cheapest way to make a AA joule thief HV?

After trail and error i have made a joule thief with the following: 2n3409 transistor, 1k ohm resistor, led, and an air coil. what would i need in order to boost the power up to say 100v or more? the cheaper the parts the better, at least for now. I've read some what about micro controllers and using 2 555 times, but i am unable to use anything that requires a computer. everything needs to be simple enough to be used via a bread board. I am desiring high enough frequencies and voltage to jump a small spark gap. i am aware the spark is waste, but that is the point.

Question by freenergyfuture   |  last reply


making solar boat using 4700uf capcitor to store energy to drive motor but not working

Making a solar boat model in which i hv designed a ckt in which i am using a 4700uf capacitor to store power but it is not capable to drive motor even for seconds when power is off pls suggest some appropriate methods to increase my storing capacity in minimum charging time i hv also tried 10000uf cap but not working with that also pls help

Question by bestads27   |  last reply


Blown outlet help

While working with HV I got a short on the primary side for some reason. I thought "no big deal, just go flip the breaker (it actually flipped my personal 15 amp breaker that's used with my HV projects, and the 20 amp room breaker)." So I go reset the breaker, and now all of the outlets in my workshop work except the outlet I had my projects plugged into. ehhh..... WHAT DO I DO!!!!!!!!

Topic by guyfrom7up   |  last reply


Solid state tesla coil design? Answered

Well, I am planning to build a solid state tesla coil. I've already build a spark gap one, but the amount of control over the output offered by sstcs looks more enticing. I have been looking at many different designs, but I think I want to go with a design based off of Richie Burnett's sstc. http://www.richieburnett.co.uk/sstc01.gif http://www.richieburnett.co.uk/sstc02.gif Those are the schematcs. The first problem I'm running into is that he is running off UK mains, which are double the voltage from the US mains. Will the output of the tesla coil still be good if I am switching ~120v through the primary as opposed to the ~240v in the drawing? Would this mosfet (https://www.onsemi.com/PowerSolutions/product.do?id=MTW32N20EG) work in the power stage, or should i get a higher voltage/lower current mosfet? I also need a substitute for the mosfet in the logic stage. Does it even need to be a mosfet? Could I replace it with a transistor? The regulation circuit also worries me. Doesn't a linear regulator need to be fed a voltage of at least 2 volts higher than the output in order to function correctly? I just realized how many questions I really had about it. Wow. EDIT: I uploaded the pics for the sstc. The first two are the ones that I linked to, the third is Steve Ward's mini sstc. I was deciding between which one to use, but chose Richie's because Steve's has so many ICs and seems to be over-complicated.

Question by duct tape   |  last reply