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Ferrite Beads

I want to make one of those joule thiefs and I live in the USA. I don't know why I want to make it, I'd never need it/use it... BUT I MUST HAVE IT!!! I'm looking for tiny ferrite beads (toroidal shape) that are cheap (less than 10cents a piece). They CANNOT be leaded

Topic by guyfrom7up    |  last reply


Homemade Ferrite - what updates do you seek most?

First a massive thank you for the interest in my project - I certainly was expecting this great response! Some might already know my first tutorial on how to make your own ferrite, here: https://www.instructables.com/id/Make-your-own-Ferrite-to-improve-magnetic-fields/ As the muber of followers grow and so the hits on the linked video I was wondering what updates you would most interested in! I want to make some custom pot cores for small HF transformers in the 2-20kHz region. So the question is what new recipe you would like to see... There are several options, all would include some mould making first: Clay as a binder Ceramic as a binder Using some non-hygroscopic salts to melt into the ferrit powder as a binder - all three would require to finnish the parts in a good oven 2K glue or fibreglass resin as a simple dry mix 2K glue or fibreglass resin with vacuum curing to remove all air - this might require special glue as in my experiments resin and glue start boiling long before total vacuum is reached, was thinking of casting resin istead as this would be rated for vacuum preparation From past experiments these are the most likely candidates to result in a good product, if you have other ideas and suggestions post them here. Being a guy that loves to keep things simple and prefering the use of scrap / easy to obtain parts I would obviously love to know where you struggled with your creation of ferrite. I still did not find a good source for rare earth materials in fine powder form to add to the mix but don't think it is an issue as for high performance there are always commercial cores available. Some people asked my what the best was is to make a big toroid core for Rodin coils and other unuasally big cores for transformers. If you are one of them, leave your feedback here as well as the size is only an issue in terms of avoiding cracks during the curing. Let's get the party started! :)

Topic by Downunder35m    |  last reply


Can anyone help me make sense of a ferrite core datasheet? Answered

I need help understanding a datasheet for some ferrite cores I bought to wind transformers on.  This is the datasheet: http://www.ferroxcube.com/prod/assets/tx513219.pdf.  The main thing I need to know is the inductance per turn of wire on the core so I can design the transformers to minimize inductive reactance and such.

Question by UbuntuNinja    |  last reply


How much power can this ferrite core take?

I have a ferrite transformer core and I was wondering how much power it could take?  And at what frequency would you recommend I drive it? I am planning this for a HF battery powered inverter I'm planning 24-36V input,  200-400V output.

Question by The MadScientist    |  last reply


Inductor winding?

Once again, I come to you for help. I recently became interested in some kind of 555 device metal detector. The schematic calls for a 10mh inductor. However, my local Ripoffshack doesn't carry inductors, and instead I decided I could make my own. It's just a coil of wire right? Right, so I have some formulas to find inductance given things like length and width, and I wondered if there's anything I need to be aware of. Does a ferrite core increase inductance? Where can I get a ferrite core? Do I need one? Is there a sweet spot for inductors? Thanks, Mr. Merino

Question by mrmerino    |  last reply


Any particular uses (electronic) for long ferrite beads? (toroids)?

Am aware of toroidal ferrite txformers used in Joule Thief apps,any other uses for the 'longer' ferrites ?

Question by chadeau    |  last reply


Can secondary winding be first? Answered

I already have the ferrite with 250turns on it. if i wind the feedback and primary over the secondary will the circuit still works.

Question by ARJOON    |  last reply


What kind of a toroid (specifically) do you need to make a joule thief? Answered

I've literally looked everywhere for what kind of a toroid you need for a joule thief, but no one gives a specific number range or type; the most specific was, "high permeability ferrite toroid". I've been searching high and low for a reasonably priced (including shipping) high permeability toroid for over a week, and I've ended up empty-handed. What's considered "high" permeability? The best one within my price range seems to be a pack of FT50A-75 toroids that I found on eBay. I looked up the specs: Inner Diameter:  0.312  inches Outer Diameter:  0.500  inches Height:  0.250  inches AL Value:  3000  µH/100 turns Which would be 300nH per single turn? Is that high or low permeability? Will it work on a joule thief? Am I making a mountain out of a mole hill? Can I just buy the cheapest ones I can find on eBay? (Even though the seller even specified "low permeability" in the description?) And I don't have any old electronics that I could try to take apart to salvage it from. Please don't say to just buy it and try it... It's about 6 bucks, but I'm in a situation where I really need to save every dollar I can. I really can't afford to just spend money on something that might not work. If it doesn't work - and I'm usually unlucky, so we can assume that it won't - I'll have to buy more, for probably a more expensive price, and that's more money that I just can't risk. Money is a big factor, so what's the cheapest toroid that I can get?

Question by a Canadian    |  last reply


Where can i find a ferrite toroid for my joule thief? Answered

Where can i find a ferrite toroid for my joule thief? Iv'e opened almost all the devices in my house!!! Just wanted to make a simple joule theif. I dont have any CFL's to open.

Question by TheMasterThingMaker    |  last reply


How many more times do you have to wrap a ferrite rod to achieve the same power as a toroid bead?

So recently I found a neat low-voltage fluorescent driver instructable, it calls for a large toroid as its inductor, I dont have any large toroids, but I do have a ferrite rod.  What I want to know is if I have to wind 90 turns of wire on a toroid, how many do I have to wind on the rod?  I know it has to be more because the rod looses EMF through its ends.                                                                                                                                   thanks in advance,                                                                                                                                                             Junits15

Question by junits15    |  last reply


What is this mystery electronic component? Answered

I bought an assortment of components: resistors, diodes, capacitors, all mixed together on about a meter of cut tape from a reel for an automatic PCB populating machine. The original reel was marked as surplus from DEC and looks to be about 20 years old. One of the components is this black cylinder, like a very fat resistor, about 5 mm long and 3mm diameter. No resistance or diode action. Brittle and crack off with a pliers like ferrite. They do not melt or burn with a candle flame. The wire lead goes straight through and out the other side. Can be picked up by a magnet, but are not themselves magnets. They have no markings of any kind, but have shiny flecks. Are they some kind of magnetic tape position marker to tell the insertion machine what component is next? Say like a binary code?

Question by iectyx3c    |  last reply


Cheap tools that will get you started.

This forum is to transfer ideas about what tools to use when getting started blacksmithing. Everybody has to start with some tools and the cheaper, the better.

Topic by Ferrite    |  last reply


Forums Date/Time Stamp Error

When trying to view the forums in order of date, there is either something wrong with the order or just that all of the time stamps are wrong. See notes on photo.

Topic by Ferrite    |  last reply


How to i turn a computer power supply into a iron oxide creator? Answered

Forgive my english.    I am looking foward to use a  pc power supply to acelerate the process of oxidation. I want to make thermite for a science project and i want to make iron oxide.    Can i use the cables (positive and negative) of the pc power supply to make iron oxide? Thank you

Question by Peter5465    |  last reply


Carbon Fiber over Fiberglass for fabric

When making a composite anything, what is the advantage of having carbon fiber instead of normal fiberglass? I was wondering because at US composites, the carbon fiber is almost 9 times more expensive that the fiberglass.

Topic by Ferrite    |  last reply


What is this and how I can use it? Answered

I guess it is an old vacuum tube flyback transformer without a ferrite core. If I am right please tell me how to connect it. Thanks.

Question by theVader75    |  last reply


New Guide Feature?

I think that there has been a new feature added to Insturctables, Instructable guides. I assume that their main purpose is to make a list of similar Insturctables for easier viewing of related Instructables and to find other Instructables that you might be interested in based on ones that you like.

Topic by Ferrite    |  last reply


What electronic component is this? Answered

I am not sure of what this is, but I think it's a replacement for 5 turns of 28 swg on a intermediate ferrite core (ift) which is missing from the kit.  I have this kit for a fm transmitter circuit and I found this in that kit's components. 

Question by akki5230    |  last reply


Looking for big tansformer cores for high frequency use... Answered

Although I have made more and more progress with my home made ferrite I am not in the need for a big transformer core for testing purposes. Desired frequency range: 30-120kHz Required power: 2kW I looked through endless pages of theoretical science stuff, a lot of useless online listings and thought: Why not do what everyone does instead of using Google and ask my friends here? ;) So far I think an iron powder core might be better in this case than the more traditional ferrite cores due to the power and saturation levels. But what size would I really need so the  whole thing won't saturate or overheat? Ring core or better a pot core?

Question by Downunder35m    |  last reply


Why you love Instructables

I don't know if this can really be categorized as burning question, but it is what it is. This is a topic to post why you love Instructables and enjoy it so much. It is a pretty random topic, so I don't mind if there are random posts. What are you waiting for, tell the world why you love Instructables!

Topic by Ferrite    |  last reply


Joule Thief Troubles

I have built several Joule Thieves as seen in this video. None of them worked. Is the schematic wrong? I am sure that I used all the right components, and I wound the transformers right... What could be the problem? Could it be the ferrite core? I used one from an old computer power supply. Any help would be appreciated.

Topic by 1up    |  last reply


I want to remove the core from a flyback transformer?

For experimental purposes i want to remove the ferrite core from a flyback transformer. I want to be able to remove it without damaging the primary or secondary windings. I don't care if the core is ruined. Someone suggested boiling the transformer in water.  Has this been successfully done or is this an untried suggestion?    

Question by Blake    |  last reply


Mozilla wants its users to help re design Firefox

The article pretty much explains it. "The Mozilla Labs, which acts as the idea wing for the organization behind Firefox, is expanding its call for open-source contributions to those outside its base of community-minded coders and techies. Now, they want to get designers and creative types in on the deal."

Topic by Ferrite    |  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


Sucsessful Forum Post From Windows 7

I am not sure if this is the first, but Instuctables has been viewed using Windows 7! For anyone not aware, the Windows 7 beta is free to download for the first 2.5 million visitors, and last I checked it was still available. This is a link to the download site.UPDATE: Microsoft has lifted the 2.5 million download limit and it will be available until January 24th Cnet Article

Topic by Ferrite    |  last reply


I need help with the placement of my magnets, and how to connect my coils? I plan on using nine coils?

This is my first build and I am still unclear on a few steps. Mostly how many magnets and placement, and how to wire my coils together. I plan on winding 9 coils for a three phase design and I have up to 20 ferrite magnets to use. Any help would be greatly appreciated.

Question by wheatabx    |  last reply


Joule thief is not working?

Learned about the Joule Thief from Make's Magazine and used their schematic. I'm pretty new to electronics so I don't know much about components. Applying 3 V, the LED lights up, but applying 1.5 V, no light. Green wire is 22 ga, blue wire is 26 ga. Using a 2N3904 Transistor and a Ferrite Toroid. I think I "barely" got the LED to dimly light up, but it would not stay on. Am I doing something wrong? Picture available in second comment.

Question by gera229    |  last reply


Please help with qi coils! A chance to inform my ignorance!

Hi! I am working on a small wirelessly powered project and am having considerable trouble with finding a qi coil that is small enough and also has a charging circuit. Specs:1" square at most5v at 500maferrite shieldcharging circuit just as smallMy questions:1) Can I use any prebuilt coil and swap the circuit from a larger one? I feel like there is a reason I can't!2) Recommendations of specific coils?Thank you so much!

Question by Moonman0922    |  last reply


I need help on my joule thief circuit that won't function. Answered

I've been attempting to construct a Joule thief circuit but it appears the circuit won't function, even with the essential parts that I scavenged from a CFL bulb. The parts are: 112dl transistor, LED, ferrite core, 1K ohm resistor, 1.2volt rechargeable AA battery and magnet wires, 14 turns on the core and  I attempts to switch the connections on the wires, it appears no hope. I've watched all the tutorial videos on YouTube but appears to be failure. If you found a solution to resolve this issue, please explain it specifically. Thanks !

Question by BlackWolf1024    |  last reply


Joul thief how to? Answered

I've been reading some ibles about joul thief making, and most of them teach how to power an LED with a 1.5v AA battery.  That is great, if you want to power an LED with a 1.5v AA battery :) But what if I want to keep using old, weak AA batteries, as 1.5v batteries?  How do I make a joul thief that takes whatever the battery can give it, and outputs it as 1.5v?  I know the kind of transistor, ferrite core, number of windings and wire gauge all affect output, so how do I know what to use? Thanks!

Question by Morgantao    |  last reply


Found a pro membership code in my inbox :)

Not sure what caused Seamster to give a pro membership but I will do my best to make the freeby worth it. If my comments are useful for our members I will definately keep doing it and my ferrite project needs an update too. But time is a bit short due to other things I have to do, so it might be some time before I will get my hands and outdoors totally black again. Anyway, I enjoy being here and I think my inbox showed I'm welcome too, so thanks again !!!!

Topic by Downunder35m  


AC to DC adapter/charger output giving little sock Answered

My new AC to DC adapter/charger output giving little sock. And, when I use a AC tester on it, tester light up (like Ac line). This adapter use "Ferrite core transformer". Also, checked a "Iron core tranformer" Adapter, Also, some of branded mobile charger lighten up the AC tester slightly, but not giving shock... Is there any option to fix this problem...? Output is a 12.75V/1.2A. (Loads are working Perfectly) But, the body current is the problem. There are no any short-circuit. Giving some pix... (If you need full circuit diagram, Please inform, that may takes some time).

Question by arnablue    |  last reply


How to Identify or Measure Inductance?

I am gathering the parts for an ible, but I am short one part: a 12mH inductor.I can spot some inductors in electronic garbage - the wire coiled around a ferrite loop - but there are also solid state inductors. Plus, the inductors are not usually labelled with their values.How can I measure the inductance of an inductor with a volt-meter and an ammeter, but without access to a sine-wave generator?Is there some simple trick that would get me "close enough" to the true value? What would be really useful (but probably doesn't exist) is a chart or formula where you plug in the size of the core and the number of turns around it and out pops the inductance value. ?

Topic by Kiteman    |  last reply


Google Earth Flight Simulator

If you download the most recent version of Google Earth and press Ctrl+Alt+A it will open up a flight simulator. You can select from two different planes and take off from several locations including San Francisco, Switzerland, and the Himalayas. You can also start your flight at a specific location if you go there in Google Earth outside of the flight simulator, and then select the "start at current view" button which is above the airport selection box. The controls can be found by going to help and then clicking on keyboard shortcuts. It's a lot of fun and has pretty good resolution. The pics are of the Himalayas. The start-up screen with the options, Switzerland, New Zealand, and upside down over Washington D.C.

Topic by Ferrite    |  last reply


Creating a handheld Emp device

Has anyone been able to create medium sized nonexplosive EMP generator? i recently purchased 4 oil capacitors each rated around 5.5KVDC and 32uF, from what i have learned, in order to create an EMP generator, you would need a to feed it a large amount of power in to  a heavy gauge magnetic coil. I believe my caps could do the trick. I will be charging them with a  ZVS driver coupled to a self wound ferrite transformer, then rectified. As for discharging i' will probably use a mechanical spark gap. I am hoping to create something like the shock pulse generators in amazing1.com, does my setup look feasible ?

Topic by tazerboy  


cold cathode light totally interferes with my IR remote control!!!

I have a view-box for looking at negatives that uses cold cathode tubes as the light source--whenever this light is on my IR remote control for my wifi radio does not work--i have isolated it to EMI from the light not the light itself. when i covered the peripheral area where the wires and 2 ballasts are with 2 layers of heavy duty aluminum foil it drastically reduced the interference. i cant practically use the foil. Does anyone think ferrite snap cores from radio shack will work? if so-- where and how many should i put?--really need help--i have little electronic experience--

Question by roccosiffredi    |  last reply


Help with an old circuit diagram, please?

Remember my inductor thread?Well, I'm getting closer to my project. The bulk of the device is to be based around an old transistor radio. I've got hold of one (a Phillips D1018/05, if it helps).Wonderfully, I opened the radio to find it has the circuit diagram stuck inside the back cover.Unfortunately, it's only half an inch high, so, I've scanned it.Now, I have a problem:The directions I am working with are vague:Try removing the Ferrite tuning coil and then replacing it with (another detecting component which I have, but if I name it the surprise will be lost) with a 12mH inductor connected in parralel.Spelling aside, I was happy with this, until I opened the radio and found that the antenna has four wires connected to it.So, I need a few answers:In the circuit diagram, which part is the ferrite tuning coil / antenna? I think it's part of the bottom-left corner of the diagram, but I need to confirm this.The four wires all disappear through the same hole, but one is stained blue and one red - which ones should I be dealing with?The component I am replacing the coil with is polarity-sensitive. The vendor was very careful to indicate the negative electrode - which way round should I connect it? I think I need to connect the negative of the component towards the bottom lead of the circuit diagram, but I want to make sure before I kill the component.I know these are potentially-noob questions, but this is my most expensive project so far, and some of the parts required subversion to acquire, so I don't want to mess it up.(If there's anything I've forgotten to ask / say, please let me know that as well. I'd rather not reveal the nature of the final project; it's not for a contest, but there's nothing like it on the site yet. If useful advice depends on knowing what the component is, then I will reveal it, but I'd prefer not to spoil the big unveiling.)

Topic by Kiteman    |  last reply


Joule Thief Toroid not helping to step up, Why? Answered

Hey fellas..I am having problems with joule thieves especially with the toroid part.... First time I wound my Ferrite Core and the joule thief ran smoothly... But recently I had to unwind it to try other wires which didn't work.. So i again wound up the toroid just like the first time when it used to work but unfortunately this time it didn't work... I have checked everything and found that the only problem is that the toroid is not helping to step up the voltage.. When i applied 9V across it, the LED glowed but for 1.5V it didn't. So there is a problem with the toroid.. But what it is and why is it happening I don't know..I mean for the same core and same style of winding once it worked and now it doesn't, Why ?? Can anyone help me ??

Question by Arijit Chatterjee    |  last reply


What material works best as a CORE for a small coil at about 500 hertz?

I am building a small coil with 1000 turns of 36 gauge wire wound around it.  A 12 volt/ 500 hertz squarewave will feed the coil.   I want to receive this 500 hertz tone a few feet away using a sensitive receiver that i have.   However, i am having trouble figuring out what kind of CORE to use and where to purchase it.  I built several coils using various items such as steel, iron, and ferrite from a flyback transformer.  So far, the plain old STEEL works the best, but I keep thinking something else might work better.   I searched the internet, but it starts to get really confusing because of all the terminology like "flux density", permeability, field strength, mu, etc etc.  It must be something that does not retain magnetism when the coil is de-energized.  Any help would be appreciated !

Question by framistan    |  last reply


I'm bored!

 I'm really bored and I want to build something neat, can someone suggest something cool I could do with these parts?? Armed with soldering gun and other parts in my parts bins, I'm sure I could make something cool/useful?? (P.S as far as the capacitors, I wouldn't mind making a rail gun) I have this so far I want to use: Bank of capacitors (several large amplifier capacitors and some smaller power supply caps) One rather large relay switch (I tested it today, it works!) One "temporary" toggle switch, it does NOT stay on when you flick it, dual pole Does anyone have any idea?? I also have things like hundreds of smaller caps (is it possible to make an effective capacitor bank with tonnes of tiny capacitors?? I also have oodles of ferrite cores and RF chokes of different sizes (I was wondering, would the larger RF chokes I have, work as subwoofer coils??)

Topic by Punkguyta    |  last reply


2 transistor Crystal radio amplifier kit - shortwave science fair

This kit is 5.00 dollars . To order send email. Then send check.  The amplifier  has the parts soldered on top of homemade circuit board. It is tested . I listen for KCBS, KGO,kSCO and several other stations with only a small ferrite on a crystal radio..  Only the circuit board is included.  The coil and tuning capacitor are not included. Many coil and variable capacitor combinations will work up to about  13 Mhz.  There is a small wire near the output which provides feedback when it is moved towards the input.  Each station is tuned individually as the feedback is different. Wrap several turns around the input coil (not included).  The variable capacitor is in parallel with the coil. The shortwave coil can be a 1 inch diameter with 13 turns of narrow wire. Stations I pick up are Radio Havana Cuba,  Radio New Zealand , Church and amateur. There are some cautions. It could include cutting tape for your circuit design.  The shortwave requires an external antenna. Schematic included. Crystal earphone is not included. Another transistor can be added for speaker  or 8 ohm type earphone.

Topic by halamka  


What can I make with this?

So, I have a few random components and I'm bored. What project could I make with this stuff? - 2 7ft sections of 18 gauge magnet wire - Unwound ferrite core transformer - 2 Rocker switches - VCR Lcd screen (PT6955) - 3 photoflash capacitors - 50v 2200 uf electrolytic cap. - 2 1.5A 120v Pushbutton switches, 1 red, 1 black - 4 lead pushbutton switch - 6v button cell pack - 1 white led, 6mm - 2 small speakers - 6 small pushbutton switches - 2 fuses, 125v1.6vA, and 25v315A - Tiny microphone - 3 lead IR sensor - 2 2lead IR sensors - Ring electromagnet, bunch of coils - small motor - large motor - large vibrating motor - 4 9v battery clips - 1 "C" battery holder - Encoder from VCR, only the bearing, no electronics - Halogen table lamp transformer, 110v to 12v - AC Motor Rotor - Heavy duty transformer - RF Modulator If it needs anything else I can buy it, just that it uses parts from this list. Thanks.

Question by LiquidLightning    |  last reply


How do I get rid of the Hummmmmmm? Answered

In my latest project I've installed an iVO-Sound m1050 4GB portable media player in to a Magnavox D8443 Power Players cassette bay.You can hear a distinct Hummmmm in the speakers. If you touch the control buttons for the MP3 player the Hummmmm gets louder. The Hummmmm increases when you turn up the volume. Sometimes there is almost like a static-like sound to the higher audio frequencies. Sometimes the sound is more tinny. It's almost like a charge is building up maybe. When the music is playing the hum is less noticeable. The hum seems to get worse progressively the more you use the displaced controls.All controls that were displaced have been mounted in the old cassette players buttons. The tape circuits are off. The MP3 player switches with the Radio to the Amp. There is a charger but it was disconnected for now. The displaced USB port is extended to the back of the box where it also switches to the charger.What I have tried so far:- I have hooked up an Alternative MP3 player to the new Aux Input RCAs that also switch with the Radio to the Amp and the External MP3 player sounds great!- I made sure the tape heads and wires were all removed from the cassette compartment area.- I originally connected the audio with a headphone jack but now it is hardwired.- I removed the Metal back case of the MP3 player and that helped a bit. All the wiring was strung through the metal casing.- I have Tried an Audio System Ground Loop Isolator between the MP3 player and the Amp. That took away most of the hum but made the sound very "tinny" with almost no Bass.- I tried Ferrites on the Audio cable between the MP3 player and the Amp and the Power Cord and a number of other places. There was no discernible change. The cables weren't long enough to loop so I used several ferrites in series.- I have order a couple Audio Transformers so I can try and use them like the ground loop isolator if it is an impedance problem but I don't expect much different a result.- I have plugged the AC cord into it's own circuit on my breaker box and that seems to help a little.(My original MP3 player - boombox installation turned out great. The main difference is that most of the buttons were on the face of the MP3 player and only two buttons were displaced to the front of the box and that was the power and reset. The charger made horrible interference racket but you could just listen to the radio while it charged.)

Question by Kepster    |  last reply


How does this CCFL inverter work? Answered

Hello, I have this CCFL (Cold Cathode Fluorescent Light) inverter from a scanner. it powers the scanner light. That's the schematic, but I can't see all the components very good, I'm sure about everything that's noted in the schematic, but I don't know the value of that capacitor between both collectors. It's that brown one from the picture. So the question is: How does this circuit work? I'm still trying to figure out how the transistors switch, it's really weird, because when I try recreating this on my breadbord it doesn't work. And why is the first coil shorted out? What I do know about this is that it has an output voltage (very low current, serveral micro amps) of 2 to 3kV. It also works at a very high frequency, about 30kHz I think, and it has a ferrite core transformer. The primary windings are very thick, and there are about 10 turns. the secondary has Many windings, a few thousand. The primary current is limited by the frequency (Xl = 2*Pi*f*L) so high frequency means high resistance of the coil, and that means a low current. now  how does the switching process work? and what's the use of the brown capacitor?

Question by DELETED_Electorials    |  last reply


Why won't my flyback transformer work? Answered

I have a flyback transformer that I pulled out of an old tv that I didn't use, and I have been trying to hook it up to a driver to get some arcs. The driver I am using is a basic driver that utilizes a NPN 2n3055 transistor and a couple of resistors. I am powering it off a 12V drill battery. Additionally I have checked the transistor with a multimeter and it checks out ok. As far as the coils go, I have tried using coils that I located on the flyback, and I tried winding my own on the exposed ferrite core. What happens is I hook it up to the power source and nothing happens, I don't even hear the high pitched whining noise that is characteristic of the high frequency driver. I don't know what to do, I have tried a lot of stuff. I'm starting to think that maybe I'm having power issues? All the instructables that I have seen use sealed lead-acid batteries which produce more current than my drill battery which is at least 12 amps. How much current is needed? Any suggestions to get this working would be well appreciated. Thanks :)    -Andrew  

Question by jarheadwithm16    |  last reply


Does any one know how to make an Ne-2 joule thief ??

Recently I’ve been researching on how high voltage joule thief works. The popular high voltage joule thief videos out there are known as Jeanna’s light if I’m not mistaken. I also built my own little LED joule thief circuit, it appear success after all with a 2n3904. But I want to take the concept a little bit further, so I decided to attempt on the high voltage joule thief circuit. It appear no luck, I have 120 turns for high voltage on my ferrite core (1 turn = 1 volt). I know it’s the same principle as the LED joule thief but with the LED removed. I have two 1kohm resistors and I connected them in parallel to get 500ohm resistance. I connected them all like the LED joule thief, but it seems like I did something wrong.  So I ask for further instruction. Parts that I use: 40 or 30 gauge magnet wire (high voltage windings) 20 gauge magnet wire 2n3904 transistor (Don’t know if that’s the right transistor for this circuit, but it’s for experimental purposes only.) 2x 1Kohm resistors in parallel = 500 Ohm resistance AA rechargeable battery. The thick magnet wire are 7 turns.

Question by BlackWolf1024    |  last reply


Snubber network? Answered

Although my flyback transformer driver appears to work very well up to 18V operation, the arc length is not satisfactory. I increased the voltage to 25V which allows 2 to 3 inch stable / hot arcs. However my 250V 18A rated MOSFETs appear to fail periodically esp. When adjusting the potentiometers (for adjustments to drive frequency and duty cycle) I Tried sticking a 1N4007 reverse biased diode across but I don't think it changed anything. I still see >300v positive voltage transients. I also tried using a neon lamp without a ballast resistor, but it did not appear to change the waveform, and glows way too brightly. I tried using 3 (really old but giant) 30V zener diodes in series but they latched up, failed, and went up in smoke lol! So clearly these HV transients have a lot of "oomph" behind them. D:  I am reading an article on maxim electronics page about snubbers https://www.maximintegrated.com/en/app-notes/index.mvp/id/848 and I'll experament with some of the circuits presented there but I can't really calculate values needed for the components because I have not characterized my transformer with custom windings and a loose ferrite core. Those things will be subject to change anyways since I do not plan on supplying a specific flyback transformer with this kit. So I want something that is more universally going to work. This high voltage is just  PITA to deal with. How can I reduce it to 200v without hurting performance?

Question by -max-    |  last reply


DIY Wallet Challenge Winners!

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Topic by canida    |  last reply


Magnetic actuators - anyone here ever made one?

Magnetostrictive alloys like Galfenol are not only quite cheap but also quite possible to produce and machine at home. As it seems that right now I can't finnish anything without being stopped by something else that got my attention I am a bit stuch on all ends now LOL Anyway, I still have a few kg of rare elements like Gallium, Bismuth, Antimony and such that I misused for my testing of home made ferrites. So apart from making some fancy metals that melt at very low temperatures I thought a much better test usage would be to make something that for once has some real world use :) If you look up some of the research papers for Galfenol use or magnetostrictive materials in general you soon learn two things: a) You need a degree or have studied something related to fully understand the technical stuff behind it. b) Finding something that would give you enough info to make something that works as planned is next to impossible. I don't mind wasting some time on melting steel, machining some samples and do some testing but of course this takes a lot of time... So I was wondering if anyone here already experimented with magnetostrictive materials and their possible uses? Apart from micro actuators for minature things I don't have I was thinking of generator use. A lot of things produce wanted and unwanted vibrations, magnetostrictive alloys are capable of transforming them into electrical energy by simply using a coil around the material. For example the recoil of your favourite hunting rifle could in theory charge your dot sight or laser sight/flashlight. Or the otherwise useless vibrations of big machines or rock tumblers can be turned into something to charge your phone. Not to mention impact sensors or flat surface loudspeakers....

Topic by Downunder35m  


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