On capacitors and polarity.

(Asked twice already, but for some reason was not visible.) That is sort of a blanket question. I'm wondering: 1) why only some, and not all or none? 2) what (in their physical structure) causes them to have polarity? 3) why do we make ones that have polarity? Is there something prohibitive, like cost, or safety, making it so in the production? (okay, not safety, as may attest anyone who has seen a reversed capacitor explode.)

Question by V-Man737 9 years ago  |  last reply 9 years ago


Need help identifying a capacitor (from a drill that exploded in my face!) SOLVED

Help! I am incapable of identifying this capacitor.The capacitor says KPB 7301 B9 0.15 μF +2x 2500 pF XY 250V~, and I'm not entirely sure what this means, and what I need to maybe buy to replace it. is it a .15 microfarad one, two 2500pF in one, or both?While drilling a small hole in aluminum, the drill suddenly made an insanely loud explosion sound. Freaked the spinning drill bit out of me. I took it apart and found this exploded capacitor I need help identifying, to replace. It's an old drill that also powers my mini circular saw and bench grinder, SKIL 1437 H1.Thanks!

Question by Yonatan24 10 months ago  |  last reply 6 days ago


can electrolytic capacitors catastrophically fail or explode if they are shorted out? Answered

My father (an electrical engineer) told me that if a capacitor is charged and than shorted out than it can fail, possibly with explosive results. However I have seen way to many Youtube videos of capacitor banks being shorted and nothing but a big spark happening. Who is right? Can anybody help me?

Question by junits15 10 years ago  |  last reply 2 years ago


Over-Charging Capacitor

What happens if you connect some form of dc power source that supplies 100 volts to a capacitor that is rated for 100 volts, and leave it plugged in for a long period of time. would it eventually "over charge" and explode? would it over heat? would it loose its  ability to store energy?

Topic by merlinj 3 years ago  |  last reply 3 years ago


Camera Flash capacitor

First off I'll tell you to NOT TOUCH A CHARGED CAMERA CAPACITOR, IT HURTS. I had a disposible film camera that I took apart. How do I discharge it? If I cut one of the leads off the compacitor would it discharge or explode, damage the circuit board? How long would it take to self discharge?

Topic by popit 11 years ago  |  last reply 9 years ago



capacitor bank questions.

Hello all, this'd be the first post i've ever made, and may be in the wrong place....... edit- i guess it was in the wrong place, since no one replied.... so i'll try here.... i'm tryin to make a cap bank from 30+ flash cameras (possible? possible outputs? how do i calculate that?)  and i have some question/problems. is it possible to take a bank like the above and use as a spot welder?   if so, how would i trigger the spark without the trigger becoming the spark gap?  another possible use i have for it is a rail gun...... theoretically, if counter evidence isn't provided by all of you much more tech inclined ibblers a second concern is that the caps come in at least three different micro farad ratings. would one explode if it's rating is lower than the higher ones?  (the ratings are between 80ish to 150 ish (don't remember)) i rather need the weilder for a possible steampunk project that i just bought a bunch of metal junk for....(knowing me though, i'll never get around to doing it....)

Topic by badideasrus 8 years ago  |  last reply 8 years ago


Where to buy large capacitors for cheap? Answered

Building various things, like tesla coils, railguns, and wire exploding devices, reguires very large capacitors. I need to know where to buy some with high voltage and capacitance rating around 450v and 10000uF.

Question by macgyver603 9 years ago  |  last reply 3 years ago


Charging 330V 110uF Flash Capacitor With 2KV

Hi there, I have a capacitor which is 330V 110uF and I have a inverter which converts 3V to 2KV DC. I know it is wrong to charge capacitor with it but I used it to charge the capacitor many times and it still didn't explode. Please explain me

Question by zates7624 1 year ago  |  last reply 1 year ago


Why do some capacitors have polarity? Answered

(Asked once already, but for some reason was not visible.) That is sort of a blanket question. I'm wondering: 1) why only some, and not all or none? 2) what (in their physical structure) causes them to have polarity? 3) why do we make ones that have polarity? Is there something prohibitive, like cost, or safety, making it so in the production? (okay, not safety, as may attest anyone who has seen a reversed capacitor explode.)

Question by V-Man737 9 years ago  |  last reply 9 years ago


Cordless drill power supply

I am using an EFUEL 30amp 18volt 540watt (model sk-200013)  power supply to power my Ridgid cordless tools. A dead battery was gutted and a power cord was soldered onto the circuit board inside the battery enclosure. My problem is that I encounter an OCP (overcurrent protection) error if I do not slowly power up my tools. I can live with this except for tools that are not variable speed (circular saw). If a Ridgid cordless tool demands full power at start up then the OCP error condition is triggered. My question is that I have heard that the installation of an external capacitor will eliminate the ripple effect and smooth out the power demand on the power supply so that any tool used at 100% demand at start up  will work without causing the OCP error condition. Is this correct? If so, can anyone tell me the type and value of the capacitor to use? Any help is appreciated. JEM213

Topic by JEM213 4 years ago  |  last reply 4 years ago


What will happen if i use a capacitor that has a farad measurement that is less than what is required ?

The voltage limit is properly matched, only the farad measurement is not the same. IMPORTANT WILL THE CAPACITOR EXPLODE?

Question by La Tour Rouge 10 years ago  |  last reply 9 years ago


Ker-Pow!-citor

So, my circuits professor described electrolytic capacitors today, and said that reverse-biasing them could cause a catastrophic, eye-popping explosion. All that in a little metal can? I had to try it! Here's what it takes:

Topic by stasterisk 11 years ago  |  last reply 11 years ago


Polaroid Portable dvd player does not play dvd's!?

And when i open it i see an exploded capacitor on the inside. should i replace this capacitor? Also since it has video in i could use it as a tv or something,so i was thinking,could i turn the screen backwards so that the screen is visible when you close it,so its flat? mine is a Polaroid PDM-0711 Here is a picture of the type of dvd player that i have

Question by ReCreate 10 years ago  |  last reply 8 years ago


The rite resistor to charge this super capacitor.

    Hello I was wondering what resistor you guys would recomend for use in a capacitor charging circut. I can follow common sense for a small 160uf 300v photo capacitor. But this cap has a rating of 3,700uf and 600v. And considering its in issue, (which I believe it may be,) assume your giving it 18v of power from let's say... a drill battery.                                                      Thank you.

Topic by darthDIY 9 years ago  |  last reply 9 years ago


Question dealing with high volt capacitors in series

As we all know (at least most) you can get free cameras at places that recycle disposable cameras. After having my fun hooking then in parallel to attempt coil gun, or just melting holes in water-filled soda cans. But I wanted to try to hook some in series, so instead of 320V, i got 640. I know series adds up so both are fully charged to 320V, but heres my question. 1: Can they ever blow seeing that the output is 640 yet their rated 320? 2: If i discharged between then, can i have a greater chance of them exploding comparing to parallel hooked?

Topic by Killa-X 11 years ago  |  last reply 11 years ago


What cap. do I need? Answered

I was looking at this instructable ignition coil and I built it without a capacitor, it worked fine except the coil gets hot after even very short run-times.  So he confirmed that I needed a capacitor to stop the overheating. So I added one.  I used the kind he told us to use (film) and I tried multiple ones, but none worked.  He told us not use the metal can type so I didn't at first, but later I got a really big one and tried it.  It was the only one I got to work, but then it exploded, so now I don't know what to do.  He hasn't gotten back to me, although it hasn't been very long so I don't accuse him, I would just like to know.  The capacitors are storing a charge, its just not running the coil for some reason. 

Question by jj.inc 7 years ago  |  last reply 7 years ago


LED Snake

I made a new Instructables, my 4. Its called the LED Snake . Its made up of lot and lots and lots of LEDs in different colors, red, green and yellow. It can serve as any kind of decoration, or you can attach it to your car or bike and lots more.The LED Snake can be modified and hacked to blink , fade ... The lenght of the LED Snake is up to you, mine is 1m long! You can make this project under $ 10!To see how it is made and how you can make ti visit the instructables!https://www.instructables.com/id/LED-Snake/

Topic by comodore 10 years ago  |  last reply 10 years ago


How can I make a solar charger for extended battery/capacitor life?

I want to build a solar charger that could keep a rechargeable, say, CR2032 battery always trickle charged without damaging anything. I want to make this circuit as simple as possible. I want to just hook up a solar panel, with an operating voltage of 3V that delivers 1mA, to a rechargeable CR2032 that was in-use. Assuming the solar cell was delivering power for 12 hours in the day, would what could go wrong? I'm sure there could be some danger, but I don't know enough. Do I need a charge regulator? Can I charge the cell and also consume power from it? If it's forgotten about for a year, will the battery explode? Can this be done with a capacitor? Can I keep trickle charging a capacitor that is attached to say a heat sensor which uses very little power?

Question by JamesS691 2 years ago  |  last reply 2 years ago


NEVER DO THIS! my story.

So, i have been working on making a coil gun. and for that, i need a cap bank. so i took twenty caps from cameras and put them in parallel. it was a lot of capacitors. i went to go charge them up late at night and believe me, that was a big mistake. i flip the switch and started waiting for the light to come on. until, i cap exploded. i couldn't hear for almost 15 seconds. it scared the crap out of me, and i am sure that it would of hurt if i touched it. don't do this. i got in big trouble from my mommy.lol.

Topic by DELETED_DELETED_kruser495 11 years ago  |  last reply 10 years ago


Budget for Zombie FX?

Hallloo. I am trying to come up with a budget for make-up and gore FX for a decently funded Zombie movie. Usually I work with an existing budget, and I've never done anything this extensive. There are 8 dessicated zombies, a few of their heads explode, one human head is destroyed with a sledgehammer, drill-bit in the eye, that kind of thing. Any advice, past experiences, memoirs, etc. would be wonderful. I'm a sculptor by training, so that's how I'm looking at this project. Like gross kinetic sculptures. Yikes, and away!

Topic by underpalace 11 years ago  |  last reply 11 years ago


Half bridge in "A reliable plasma speaker doesn't work"?

Hi! I am a  student and I just started to make my first half-bridge plasma speaker, and I used the schemetic in https://www.instructables.com/id/A-reliable-plasma-speaker/ However, after I finished, it didn't work. I used an oscilloscope and I found the VGS of high side MOSFET was between -3 and -6, and the low side was between 12 and 0. Then I accidentally got it work, but the MOSFETs were very hot, and then they exploded. After I change the MOSFETS, it had the same problem as before again. But if I short the capacitors, the wave form for both the high and the low were correct. can anybody explain why? Thanks.

Question by carldong 7 years ago  |  last reply 6 years ago


Bike Lighting - Pedal-Powered 60W Incandescent Bulb?

I know, I switch projects a lot. I just can't stay focused on one thing for too long.Anyway, here's my idea:There's a local museum called Fort Discovery, which, by the way, is quite cool. But, there is this exercise bike they have there, and connected some how (I haven't been there in a while) is a few different home tools, like an incandescent light bulb, a drill, a hair dryer, and something else. There are switches, so you can turn whichever ones you want on, to see what you can power. The "exhibit", if you will, is to show how work = power. Now, I'd like to try to hook something like this up, except a few things will be changed:It would be a regular, moving bike.There would only be a light bulb.I want the power to be stored in a capacitor, because what would be the purpose of having a light while riding in the daytime?Now, besides from the point of me not knowing at all how to hook this up, I wonder if there would be a capacitor that would store enough power to light the bulb for a reasonable amount of time, if say, I used a 60 watt bulb. Then of course, I have a few questions, some of which I may of already said:How big would the capacitor have to be hold enough power to light the bulb up?How many hours (or minutes, if applicable) of moderate riding would it take to store enough power to light the bulb enough to see for about 15 minutes?Would the power stay in the capacitor so that I could charge the bulb a bit over the course of a few days?How would I hook such a circuit up?Could I hook the circuit up so that the power is stored from the wheel going around, rather than my pedaling?Thanks for any and all help, and if this turns out all right, then I may just put an Instructable up. I guess I'll have to see. Thanks again!

Topic by Bran 11 years ago  |  last reply 11 years ago


incandescent light flicker hacks

There are 2 hacks with incandescent lights that make flickering effect. may be usefull for some haloween stuff here is the most basic description. if you build it be carefull in fire safety - some stuff may overheat and blast / catch fire. use non flammable boxes if needed. starters and diodes may explode if connected incorrectly - always protect your eyes do not do any of the hacks with CFLs - they are for incandescents only. they may work with LED lights depending on other components in the ciruit and the amount of current (if there are capacitor / induction / electronics / transformer in the LED circuit then dont do it) hack 1 - slow flicker (i saw it somewhere on instructables before) connect the incan in series with fluorescent lamp starter (the neon discharge type) you may connect 2 starters in series. i'd expect longer outages this way. if they dont light (not enough voltage) then use the starters designed for 2 x 18 W fluorescents. warnings dont connect the starter (or series of 2 or more starters) directly across the ac source. the starters will blow immediately and may explode. check that in any possible path through the starters there is an incan light dont connect stuff in parallel unless you really know what you do. lights connected in parallel take the sum of the currents they take on their own - anything more than 1 light is too much for a starter (or any amount of starters in series - each gets all the current) part 2 - fast 50 Hz flicker connect the lamp in series with an 1N4007 diode. the diode blocks 1/2 of the ac wave and makes some light flicker. seen best in low watt lamps with thinner filament (with less thermal capacity) diode may be used together with starter to combine the effects this hack is used widely in heating appliances that have 2 heat settings. in the lower one they are connected thru a diode

Topic by 11010010110 10 years ago


Help with building a tesla coil? Answered

I want to build a tesla coil, but I want to verify with the instructables community that it won't blow up, burn down my house, turn into skynet, etc. Here's my plaaaauuuuuuhn: For the transformer, I'll be using an old negative ion generator thing that takes in 120VAC and outputs 7.5kv(pic). For the primary, I'll use old speaker wire in  a cone shape (possibly using acrylic). For the secondary, I'll use 32- gauge magnet wire (pic). And for the spark gap, I'll use two bolts in a box, possibly with a computer fan cooling it. And for the capacitors, I'll just use an array of Leyden jars. My questions: 1. What diameter should the coil form be? I have some random white tubing which has an OD of 1/2 inches, 1/2 PVC piping (which actually has an OD of 7/8 inches), and 3/4 inch PVC piping. And is there a better alternative to these? 2. Should I use chokes on the input/output of my transformer? For those, I think I'll just wrap a bunch of wire around a pen. 3. Should I varnish it? 4. How powerful will the EM be from this thing? Exploding computers aren't that good. If I have made any errrors, please tell me.

Question by Shagglepuff 9 years ago  |  last reply 5 years ago


Motor Speed Controller. I have recently purchased a 115v Bodine Electric 42R Series AC Induction Motor

 I want to be able to control the speed of this motor to use for my homemade brass reloading tumbler. I am currently using a cordless drill which is not practical for the lenght of time the brass must tumble. http://www.youtube.com/watch?v=cvunTv-5x7A The specs for the motor are as follows.. 42R Series AC Induction Motor Standard Features Totally enclosed IP-20 rating. Fan cooled for high output power. Class "B" insulation system operated within Class "A" limits to prolong winding and lubricant life. Aluminum center ring and end shields for high thermal efficiency and light weight. Permanently lubricated, noise tested ball bearings. Locked bearing design minimizes shaft endplay. Application Information Capacitor is not included. Order with motor if required. Models are available with either NEMA C face mount or base mount. Any suggestions would be greatly appreciated.

Question by ehays 8 years ago  |  last reply 8 years ago


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 2 years ago  |  last reply 2 years ago


Rgb matrix, looking for some advice/guidance.?

Hi, its been quite some time since Ive been here. And I still have the same two projects in mind. However, the project im more focused on, is a 32x16 RGB led matrix. Made up of four sections. Im following the project by the two guys over at solderlab.se. They arent very active and speak a different language so their english explanations arent as thorough as Im looking for so I figure id ask the people here :) So, the main questions I have: 1. What kind of material can I use to put the leds on? its like they use thick cardboard or wood. they drill all four holes per led so the legs go through. I want one big board instead of two.  2. What spacing would be good to make it look uniform, yet give enough space to solder?  3. How can I make the 4 controller boards to run it? - They sell them, but they arent cheap. And they dont deliver or sell to the US. So Ill have to make them somehow. I can provide images/part list of what they used.  4. What type of solder/soldering iron would I need? Obviously various temp. But what temps would be safe?  5. What power supply can I use? Ok so, any other info: -They used common anode LED's  -They connect the boards together via ethernet cable.  -They connect the led's together in four sections of 8x16, The anode is connected on each of the 8 rows. And the anodes on all the led's are connected on the 16 rows. If that doesnt make sense, the anodes are connected vertically, and all the cathodes are connected horizontally. -They connect the 48 cathode wires to ribbon cable, that goes to the controller board, same with the anode wires.   -They connect the boards to a Usb to UART connector -Lastly, Part list of one controller board:  HEXFET IRF7314 x4 TLC5940NT x 3 28 Pin IC-Socket 300mil x 4 Resistor SMD 0,25W 1% 10K x 10 Resistor SMD 0,25W 1% 2K2 x 8 Resistor SMD 0,25W 1% 2K x 3 Resistor SMD 0,25W 1% 220R x 2 Resisitor SMD 0,25W 1% 1K x 3 AtMega 328P x 1 74HC138 SMD x 1 Ceramic Capacitor 22pF, 20% x 2 Oscillator 16,0 MHz x 1 Pinheader 2x8 Pitch 2.54mm x 4 Jumper x 3 Pinheader 1x2 Pitch 2,54mm x 7 Modular Jack x 2 Ceramic Capacitor 100N, 20% x 5 Electrolytic Capacitor 680uF x 1 LED 5mm blue x 1 LED 5mm green x 1 Screw terminal 5.08mm x 1 If theres ANY more info required please ask. It said to be as detailed as possible.

Question by 'earl 6 years ago  |  last reply 6 years ago


i'm making a boiler can i use a one way valve? Answered

So i'm trying to make a boiler system so that i can get a little bit of energy back from my forge the idea for the forge is to basically cut open a 55 gallon drum on the bottom flat side and put a forced air pipe in the small orifice normally used as an air hole when dumping the barrel. then i'd cut out the space needed to fit 4 inch stove piping where the larger 2 inch orifice is and carry the exhaust outside and out of mind. then i'd cut a hole in the bottom of the barrel so i can get my work in, put in a steel plate that was cannibalized and drill a few air holes in it, put refractory cement everywhere and bob's your uncle. what i want to do however is to put some water pipe in the fire box and have it turn a turbine or something, i'll cross that particular bridge when i get to it. but the main question is how can i safely store a reservoir of water so that the pipes don't run out of water halfway through a burn cycle? the thought was that i'd invert another 55 gallon barrel and connect it to one end of the pipes with a one way valve. the only question is would the valve guard the second barrel from the pressure generated while still allowing the water to flow in when necessary? or would the barrel just load up with pressure and when i hit 20 psi it just explodes in a hot watery mess? any knowledge about this would be great, stuff like where to get cheap but good pipe in upstate new york, where to get regulators, how to find the valve itself, or even where i can find safety fittings like pressure release valves and temperature control.

Question by waldosan 7 years ago  |  last reply 6 years ago


Material Section

Hi there!I hope this is the right section to post this in, if not then i'm sorry i picked the most probable one (i hope D: ).First of all i love instructables, i'm using way too much time in on this page than i should, but then again if it wasn't or instructables i wouldn't have this cool new Hard Drive Speaker present for this cute girl i like ;)In any case let me get to the point; i would like to suggest a Materials Section for Instructables - basically it would include material stats and an in depth explanation of the material (or component if we're talking tech here, but that's a different area). Here's an example: in an instructable, the author mentions plexiglass and that it needs to be bent. Many don't know that plexiglass isn't class, but an acrylic hardened plastic substance with abilities much like glass (but not quite). Plexiglass can fracture, but wont leave extremely sharp pieces like glass will and it can be bent when under medium-high heat from a heatgun or the like. Also that high friction (from a drill or the like) will cause it to melt.Basically what i mean here is that this section would greatly reduce the time an author spends on making his ible by letting out basic facts. E.g. instead of writing "plexiglass is..blah blah" the user would be able to look up in the materials section and read in depth for him/herself what the characteristics are for plexiglass/plywood/capacitors/batteries and so on.The materials page could be powered by the "burning questions" competition i've seen on this page. I don't think material characteristics fit in ibles because it strictly isn't - it's a data sheet that lets you understand the materials and components you're going to use in an ible.PS: sorry about the lower case i's and the occasional typo or grammatical error i'm not a native english speaker . also i really hope this is the right section to post in...

Topic by Eirinn 10 years ago  |  last reply 10 years ago


A couple questions

Hey guys, I want to bug you's again. Instead of trying to ask about different things in one of my other topics, I wanted to start a new one. I went to the local dump today, and one of the first things I spotted was Three, not just one, booster packs. You know, the ones you can charge up and boost a car with, and some of them have inverters built into them so you can run small appliances. Well I snapped all three of them up, thinking that at the very least, the lead acid batteries inside them would be OODLES of help towards making a full scale wind generator (I plan to build one or two full size wind generators with car alternators, whenever the good weather comes and I can work outside). Well, I got them home and cracked them all open. Turns out that only one battery is good to me (pictures below). The two identical units have 350 watt inverters built into them (I've removed one so far), but the batteries were bulging and the sides were split open, although not leaking, which was good, less mess to clean up. The third booster pack I opened appeared to have been already attempted at being opened. 4 of the 6 screws had been drilled out (which is beyond me as far as why they would do it? They were only phillips screws), but maybe they weren't successful? It had a couple wounds of electrical tape around it to hold it together. Needless to say, whatever cutting tool they used, cut into the battery itself (they cut too far in, dumbasses...), and so my main question here is, is the battery safe to charge, and use? I took some macro's of the damage and some of the cut marks seemed to have gone far enough in to cut into what appears to be a white plastic lining inside, as the white crud on the sides of the battery feels more like burnt on plastic from a cutting disc than it does acid that oozed out and dried up, so the damage doesn't appear to be that bad. What's the worst that could happen anyways? Also, the battery has about almost 8v left in it, and another question is, is that too low for a 12v battery? Like has it been discharged too far? Also, aside from the battery. I found this plate with a transformer, giant capacitor, and a pcb that looks like it was some kind of voltage converter board (I would take a picture but I've since cut a few things off of it and I won't even bother now) The transformer puts out 25v and you can see in the pictures what the capacitor is rated for (I would like to know what I can use this capacitor for, or if I should save it and wait till I can make a bank of capacitors for a tesla coil project or something) What I can't figure out, is what is this square device I found that was plugged into one of the output leads of the transformer? It only had two leads coming off of it, one is marked + and one -, the other two terminals don't have marking on it. No model numbers or anything. Does anyone know what this is? Also, last in my pictures is one of the inverter boards I pulled out of one of the power-packs. I cut the second outlet off and wrapped the first one in tape just to make sure I dont' shock the hell out of myself. I have my truck battery sitting inside over the winter, and with a good 12.71v, I thought it would be the perfect battery to try the inverter on. I brushed the wires onto the top terminals of the battery and although I could hear a bit of sparking, I saw nothing and the indicator light on the power switch didn't light. The volt meter also showed nothing from the 120v outlet. So I tried shoving the wires into the bolt sockets that the truck's wires bolt into, and I quite literally startled myself as it emitted a really loud BEEEEEEEEEEP, I nearly jumped through the roof. The indicator light turns on when I flick the switch to I and I can hear the transformer making a little buzzing sound. However, when I measured the AC voltage from the outlet, I didn't write down the voltage, but it was around 3v? Not even quite that much. I'm not sure if the inverter is screwed or if it has something to do with the switching nature of power inverters causing my multi-meter to not read it right? One other thing I will note is that I had to cut the power switch leads to remove it from the case, then re-solder the switch. The switch has 2 black wires and one red, I tried my best to make sure that each black wire went to the terminal on the switch it came from, and I assume if I didn't hook the switch up right, it wouldn't have lighted up or anything right?? I don't want to try plugging something into it for fear that it will blow up in my face, at least not until I know it's functioning like it should be, however I doubt these power packs were throwing out for failure of the inverter... *On the side note* I apologize for these (sometimes) rediculously long posts or just mundane questions. However, I like to be thoughrough with my questions so that there are very little questions asked, about my question, in the first place. As it seems to waste a lot of time asking for details about this or that problem, when you could just throughly explain it all in one go. This is what I try to do, so there are no blank spaces for you guys to try and "assume" where you don't know the proper information. Secondly, I've really appreciated the help, and sometimes just the helpful and creative ideas I hear from others, makes me feel good, like there's actually some people on here that know what they're doing and I can trust their answers (Nacho, kiteman, caitlyn's dad, 1010100100, all of you regulars, have been great help to me) *End of girlish requiem*

Topic by Punkguyta 10 years ago  |  last reply 9 years ago


My Laptop Is Broke. But how? Answered

I have an old dinosaur laptop (a Fujitsu Life-book C2330 approx. 7 years old.) that worked up until very recently. I packed it up in my closet for a few weeks, and when I decided to re-purpose it, the laptop wouldn't power up. I believe the problem is not in the laptop itself, but in its power transformer. When the transformer was working, it would make a high-pitch, low volume, whine. But now the transformer only whines once for a half second every five seconds. This could maybe be attributed to a blown capacitor or other electronic mishap. If that is the case however, it would probably be more worth my time buying a new transformer. My second idea is that the transformer has been damaged but usable for a while, but the laptop requires a slight charge of some kind in the battery to get it going, and the old transformer doesn't have the guts to give that charge. Metaphorically leaving me with a car with a dead battery, trying to jump-start off another car with another dead battery. If this is the case, then I should buy a new battery. My third idea is that both the transformer and the battery are not the problem, and it is the power jack that is the problem. I had to open the computer up not too long ago to re-solder the loose power jack. The screws that attached a ridiculously large EMI cage to the motherboard were stripped, so I had to drill them out, and then bend the EMI cage about 45 degrees. That allowed me to fix the power cord, but it also damaged my internal wireless card. After putting it all back in one piece, the laptop worked fine until I bought a new one, when I put it in my closet and forgot about it. Which brings me back to the thought that the power jack is broken. But it doesn't look broken at all, it doesn't feel broken, and it doesn't jiggle in the laptop. And if the jack is broken, I might as well just give up. The last possibility, is that the laptop, the transformer, the battery, and the power jack are all usable, but the power cord, which looks fine on the outside, might have lost its conductivity, or become frayed and detached inside its rubber casing. Which can be easily fixed by opening it up and reattaching the wires. That's my situation. I don't know which of these ideas it is, but it has to be one of them. I appreciate any help I can get. Sorry for the bad image quality. Not that the pictures help much anyway. Thanks, Sam

Question by martzsam 8 years ago  |  last reply 8 years ago


Specifics of building a multi-stage coilgun?

So I recently decided that I wanted to build a coilgun. I already knew how they function, and after some light research, I've got the main design already laid out. What I'm looking for now is some more detailed input on the exact power requirements, circuitry, etc. Specifically: Firing a standard .177 steel BB, I want to use many small coils in series as opposed to one/few large ones. From my understanding, this will provide better end speed while keeping each coil's power draw relatively lower, and thus safer. (Am I right about this?) How many coils should I use, what would be overkill, etc? Each coil will be triggered sequentially by a IR LED/photocell trigger system rigged through tiny holes drilled across the barrel. Will a simple on/off circuit suffice, or will the projectile pass by too quickly for the full charge to release? If so, I assume I need a system to trigger a full discharge when tripped. Correct or not, and if so, how? I'm also considering fitting an extra gate at the end to trigger a circuit to bleed any remaining charge. Ideas on this? What size of capacitors should I use, and how would I charge them? The only thing Google can seem to turn up is camera flash circuits, but I'd much rather have one tailor-built to the system's exact levels. I'm going to use a press/hold switch to charge them, and would like an automatic shutoff with an LED that comes on when they are charged, but turns off when I release the button. Kind of like a camera flash, actually. I'd like to fit it with a re-chargeable battery. What sort of power is required here? How many firings would I likely get per charge, etc? What sort of muzzle velocity can I expect? I don't want to kill bears with it, but soda cans would be nice. I don't want to waste my time fabricating it only to be able to stop it with my eyeball. Lastly, are there any other points of concern or things I should know? Thanks for any input, and if everything ends up coming together nicely, I'll be sure to properly document the process for everyone's enjoyment. :)

Topic by Skye Pyro 6 years ago  |  last reply 6 years ago


Solar panel uses??

Hey guys I'm needing the expert opinions of everyone here in the tech section. See I just mounted this 0.5 watt solar panel outside on a L bracket today (not just a couple tiny ones I pulled out of solar lanterns (does anyone want to see what it looks like mounted outside? I didn't think to take pictures until I got inside). Anyways, I've mounted it, ran the wire along the ground and in through my window (drilled a small hole below the window). Connectivity checks out good and I get about 20-21v and the full sun hasn't even hit it yet. The only thing is here though, this solar panel is meant as a trickle charging panel for car batteries and whatnot, and as such I only seem to be getting about 10-15ma (seriously wtf). I just resoldered this charging board from a solar lantern I had laying around, however I have a couple questions. I'm not entirely sure if this little board will handle the current/voltage (however it should as it's fairly low current from the solar panel) I've rigged up the board mostly like it was inside the solar lantern except longer/stronger wires. I have a switch on the positive line of the batt+ to the board. I soldered some thicker wires to the SOL connections on the board. Now I've seen a few of these and some are rather simplistic control boards and some actually have a bit of circuitry to them. This one appears to have resistors to current limit the LED (would be good so I don't blow it), however after following the traces on the board the led get's it's positive from that black transistor thing with 5 legs on it (what is that a power regulator?) The idea behind all of this here is that I can maybe charge up my cell with it or usb devices for example, but to have that come from a battery pack of AA's (to work as a buffer sorta-speak like a capacitor bank). I am a little miffled as how to make this work right the way I want it to. I would assume that once I get the battery pack situated I can disconnect the LED and use that connection for a charging cable, but then it would only provide power when theres no sunlight out (when you turn it on it turns the led on if there is no current coming from the solar panel). How can I do this guys I'm sorry to ask such stupid questions as I know to some of you's it's probably fairly mediocre but I'm a bit dumb.

Topic by Punkguyta 9 years ago  |  last reply 9 years ago


Ceiling fan generator mod to the max

I stubled upon several mods to convert a standard ceiling fan into a more or less usefull generator.So if you are looking to go this route then I might have some nice improvements that can be implemented.People like these mods for some weird reason, despite the fact that it requires quite a bit of extra work to make them weather proof.However, when it comes to the fundamentals then to me it looks like some folks out there are missing out.On the available power that is...Always the first step for a mod like this is to replace the induction ring with a lot of magnets.Second step usually is to remove a lot of the coils, especially the inner ring.Now, these two stator designs are common for fans with two speeds.Those with three or even reverse might have a different configuration!Lets start on the magnet part:The recommended way of placing the magnets is by creating an air gap as small as possible - makes sense.But then it is always the same amount of magnets as there is coils - and the spacing is also the same as for the coils.In the general generaotr design world this configuration is prefered as it allows for the best performance.If you dare to go a bit further and cosider how the magnets react to the stator configuration then you might want to consider a different option.You see, these two sets of coils for two different speeds mean just one thing:A different amount of poles is created, with the outer ring having more poles than the inner ring of coils.The core is split around the coils, not just to allow the windings to be made but also to provide independent paths for the magnetic field - resulting in the two pole configurations.Amounts differ by diameter, power level, manufacturer and so on.What is always the same is that the inner ring has less coils and that the outer segments of the poles created have even spacings.In the normal mods you see posted these gaps in the core for the outer ring are closed by inserting lamitaed pieces from some old transformer.And you end up with ONE usable coil configuration and ONE power output.The slightly advanced mod uses the inner coil to add some load depending on the speed to prevent spinning out of control in high winds.If you try a normal DC motor with permanent magnets than you will notice the strong binding forces, it is like the rotor sticks in certain places.The better ones use and uneven configuration to reduce this binding effect ;)In my mod the magnets are selected in size to almost be the same length as two stator poles next to each other.This allows for the best induction while still allowing "to experiment".Bringing the magnets and the coils into play...As said an exact match of the number of magnets to either coil ring is not ideal.The prefered option is to go somewhere in between.For example:Outer ring has 18 coils then the inner ring will have 9 coils - exactly half.360° divided by 15 make a nice 24 degress per magnet.But with 12 magnets you get an even 30°, which is far easier to deal with.16 magnets at 22.5° is another option.So, what does that exactly do for us?The bad thing is we get slightly less performance if you only see the standard mod with one coil ring.The good thing we get far lower binding forces and through that the thing will even spin in very light winds.Adding both coil rings with a suitable rectifier however results in a pulsing output of two sine waves.With just the rectifier we get a ripple that is easier to deal with through a capacitor.The extra power available is in the range of about 40% and make more than up for the "reduced" amount of magnets.Going the extra mile once more ;)Having created a much fancier ceiling fan mod now you might wonder if there is not a way to get even more out of it.And there is.For example by utilising a gear system or belt to get a far higher rotational speed on the generator than what the blades would provide, prefably then with quite big blades too and an automatic break for high wind conditions.With the reduced binding forces the generator will be happy to spin at quite high speeds in low winds.Downside is that you will need to build a far more sturdy bearing housing.In return though you get more stability and durability.You can do the math yourself based on the number of poles per ring and magnets to get the output frequency based on the RPM's.Perfect would now be to use a switch mode power supply configuration to directly transform the provided output into a stable DC per ring.And yes, it is possible to use mechanical systems to provide a fixed output speed from the blades to the generator - but way to complex and lossy!Lets do some lame math with no regards to realities:If the original fan would spin at 100 RPM at full speed than we could say our generator should provide the mains voltage at about 100 RPM.Keep in mind we utilise both coil rings and not just the high speed one!Geared and with the blades spinning at 100 RPM we might get as much as 1000V from this little generator....And even with the lower amount of magnets we migh see frequencies above the 500Hz range.The good thing now is that normal iron core transformers can still operate at these frequencies.A bit lossy in the upper range but acceptable for the purpose.Put simple: A 10 or 20:1 transformer per coil ring would provide us with a far more suitable output voltage and much higher amps.If you made it to here than you certainly wonder about other magnet configurations.Checking the stator configuration you will by now realise why I selected the magnet lenght accordingly.The magnets "activate" one coil after the other.The spacing between them means there is always some overlap where the magnets only cover one half of the stator for a coil.This is ok because we don't really have to worry about the resulting messy output.Ideally though you would want to have a magnet activate both coils, the inner and the outer at the same time.What we did though was to make sure that at no time more than ONE magnet fully covers more than ONE coil!It is the best option to cover both coil sets while minimising binding effects and increasing the avialable output.To go the last step you would need to invest a lot of time re-winding all coils :(You don't want to do this unless you have the means and no friends and family that might miss you for a few days....I found a far simpler way to change the coil configuration, although it is not as good a re-winding.So let's go full scale shall we?Ceiling fan reconfiguration!If you take the usual 18 to 9 configuration than one thing jumps to mind reight away: 3-phase power!Cutting the wire that goes from coil to coil might not always be possible and if it is then you need to know how to handle it.Magnet wire can be hard to solder.Burning the coating off results in corroded copper that is even harder to solder.If you are lucky though than a reall hot soldering irong will be able to melt the coating.The flux from the solder will start to cover the wire from the cut and the solder will follow.If not then using some fine sandpaper and time is the other option to remove the coating...Ok, you seperated all coil and have two wire ends per coil?I hope you did not cut off the ones going out to the actual connections to the outside world ;)Properly solder each wire end and take your time to check it is really proper and not just a few spots.Mark or number the coils on the rings!For the inner ring we have 9 but need only 3, so we start at one connection to the outside world and check if this connection is on the outside or inside of the coil.For this example I assume you picked the one that goes to the outside of the coil.Connect the inside wire to the outside wire of coil number 3, assuming we start with 1 here ;)From the inside wire of 3 you go to outside of 6 and the inside is you first new output connection.Do the same with the remaining 6 coils and where needed add the required output wire.It really helps to have wires with three different colors here, one color per new coil set.Note which color corresponds to to the three coils used!!!The outer ring with 18 coils is sightly different here.You see, we want a "flowing" magnetic field that makes best use of the new coil configuration!We can not simply bridge them in any way we feel like without considering how this might affect the electrical side of things.As we now take the approach of a three phase system it makes sense to use a more suitable magnet configuration as well.So before go to the outer ring of coils lets have a look of the best option for the magnets first:The stator packs are evenly spaced in our example and will alow us to use 18 magnets.This provides the best performance with the downside of a higher binding effect, but we need this configuration to get the best possible output.As said at the start I selected magnets that are just shy of being the same length as the corresponding stator segments.In a "free" setup these magnets would now be quite hard to place in a makeshift ring.Even harder in the original casing.A 3D printer certainly helps but some common sense too ;)Wood is easy to work with and if you select the right stuff than making a suitable ring to hold your magnets and attach to the drive system metal parts is not too hard.Bar or brick type magnets can be quite easy be utilised on a wood setup :)The key is that you add Flux Capacitors - sorry couldn't help the reference to Marty....What I mean is to add some magnetic material between the north pole of one magnet and the south pole of the other.Lets say your magnets are 15mm long and have a spacing of 5mm.Then a little plate of 12mm would be next to perfect.This plate needs to connect the magnets on the backside, the side facing away from the coils.Use a dremel tool or what you have to first create slots for the metal strips or bars, then the same for the magnets.Glue in the metal first and once set add the magnet, making sure the always go north to south with their alignment.Ok, and what does this do for us?I hope you are not one of these persons who starts building while reading...What we created now is a shortcut for the magnetic forces.The field between the magnets is severly compromised in terms of being usable for the coils.We do get a much soother run though...I only did that to have some fun and check if you paid attention - sorry :(What we really want is an effect similar to what you see on a loadspeaker magnet that is still in its metal shielding.A ring magnet with one pole on the inside and one on the outside is used here.The shielding provides a path for the magnetic field that is not going through the speaker coil - hence the little air gap for the coil.If we do the same then our efficiency will be going up quite a bit.Take two identical steel parts, like some butter knifes, and prefarbly a force gauge.If you try to pull your magnet at a 90° angle from the blade you will get a certain reading for the required force to lift it off.Most people now think that this would be the max a magnet can hold.So take the other knife and place the magnet between them.If you pull the knife off with the gauge now the reading will be higher than what you get from just the magnet ;)Taking that to our model and keeping the field lines in mind we now know that we could even use slightly longer plates if our magnets happen to be a bit short :)Just place them right behind each magnet !Back to the outer ring of coils....With 18 magnets we get an even system for both coil rings.However we want to make sure that our output waves are syncronised and not at random order.We need to combine two coils to be back on a 9 coil configuration as on the inner ring.The other option is to provide two sets of outputs for outer ring, resulting in 3 3-phase outputs.Both have their pros and cons....But if you check the 18 magnet configuration ina ction over the coils it becomes clear that combining two coils the usual way is possible but also that our inner ring does not get a proper north south action from the magnets!Only the outer coil ring works properly!For the inner ring we never get only a north south combo, instead a lot of mixes.Did I mention to read first? ;)Of course we can only use 9 magnets in our configuration, but at least I did not traick you on their size....You see, we need to account for the fact that the coils are not just evenly spaced but also that all configurations in terms of coils to stator pack are doubles or halfs.Makes a lot more sense if you know how these asyncronous motors work :)With 9 magnets we actually get both inner and outer ring coils activated properly.Plus we now have the benefit that there are always twoouter coils in sync with each other.Means apart from the same way you wired the inner ring you make this addition to the outer ring:"One" outer coil is created by going from one coilinner connection to the outer connection of the second after this, skipping one coil.The resulting output is again just 3 phases but with double the output voltage.The key is to again take notes of how you connect and wire the coils - and the colors used for the output wires!Let me give you an example for the correct order:I we take the number 1 coil on the inner ring then coils number 1 and 18 would be next to it on the outer ring.You want to combine 1 and 3, 2 and 4, 5 and 7,....And you want the resulting three coil packs and wires colores to correspond to the inner coils in the same order!That is true for the always same way of combining coils from the inner to outer connection - or the other way around but never mixed!Ok, we have done the magnets and the coil configuration now properly, no jokes this time!With two simple 3-phase rectifiers we get two DC outputs that can be combined or used seperately.As we end up with roughly double the output voltage on one output but all coils are the same it makes sense to treat them independly.For those who wonder why:If you add a load than one coil system would take a higher loading of it.Meaning while one coil set is stll fine the other will already start to overheat - if the load is too great.So we use two rectifiers with some filtering.In the basic form just a really big electrolytic capacitor of suitable voltage or a full LC filer system with multiple stages.Either way we can now utilise some better DC-DC converters to get going.Considering the equal max watss the coil rings can handle it make sense to include some current limiting.A good converter will provide this option.Both converters can now set to the desiered output or with some added protection diodes and adjusted properly to the same voltage combined for just one DC output.Compared to the standard mod of removing coils and bridgning stator packs the resulting output power in overall Watt will now be about 40-60% higher - depending on the model and quality of parts.Special words of wisdom:Consider the orignal max speed of the fan when used as intendet - see this as a theoretical max output that equals your mains voltage.Just ignore losses and such things - better to be safe than sorry.It becomes clear that it quite possible that your output will be far higher than mains voltage and that you need use transformers for the two 3-phase systems so you can use standard DC-DC converters, which have a max input voltage of around 50V only.This means your converter must be able to handle the higher amps!The fan might have only used 100W or less than 500mA but at high speeds and a ratios of lets say 10 to 1 for the gearing high wind speeds might get it up to over 5 amps on the transformer outputs.Please do the math first for your gear system in relation to the max wind speeds you want to use with your blades!If in doubt use a converter that has some reserves to offer, especially if you aim to charge batteries as quickly as possible.The most vital part however is to ensure that all previously cut wires are isulated properly!!!Magnet wire of the standard kind is good for about 1000V max, so don't drive it higher!Heat shrink with a hot glue liner is prefered but hard to apply in these thight spaces.Since nothing moves consider using long enough wires for your connections so you have enough space to solder without affecting the heat shrink tubes.Liquid insulation or rubber is the last option and should only be used to finalside the heat shrink security measures.Best option once all is confirmed to be working fine would be to make a custom mold and to fully enclose the staotr pack and wires with casting resin or an insulating casting mix.Make sure to keep the output wirese free at the their ends ;)What if I don't want to build a complicated three phase rectifier and just use a single phase system as it was?Firstly chances are your coils are already connected in a three phase configuration, just all in series.But working out a suitable magnet configuration to suit this is much harder if you want to use both sets of coils.In a series configuration like the original you also have to accept the losses from these connected coils.The higher the overall resistance the lower the possible output ;)Main problem however is to get the magnet working properly.The standard 9 or here even 18 magnet configurations still works, especially with the added shielding from behind.But the coils also produce a magnetic field, which grows with the load.Means that an top of all you also have the coils working against the magnets and create even higher losses.Explains why the simple folks prefer not use the inner coil set if they go with a single phase system.So either accept the losses and just use the outer coils or do it fully and get far mor output.And by the way: a 3-phase rectifier modlue is only a few cents more than a standard bridge rectifier ;)Ok, and why do I bother to write all this?People like to tinker but most don't really invent.Following some simple instructions is easy, trying to work it yourself much harder.The reward however is that you actually start to know what you are doing :)And what works for a ceiling fan can be used for these ring style washing machine motors too ;)Anyways...We need to get back our roots.Start thinking for ourself again, work things out instead of just looking them up.If people would be aware that a simple ceiling fan could provide about 3 times the output power of its rated installation value instead of only just about half......Super strong magnets allow real output even without re.winding all coils.And what works here works for other things too.We only learned to use magnets in a striaght way because we can not bend them.But we can bed the magnetic field lines to our advantage!The simple shielding used in this mod is nothing more than a shortcut to enhance the field strenght where it is is needed.By a simple coil modification we basically bet two electrical generators for the price and size of one.Apart from stating how easy it would be to place multiple stators and magnet rings into one generator the magnets itself also allow for even more output.If you ever played with hook magnets or speaker magnets then you know how much stronger they are compared to just the magnet once they seperate after hours of fun for you.Imagine you would replace the single bar magnet with two block magnets that are joined by a magnetic shunt like out simple shielding before.If the magnet blocks now would have a slightly smaller footprint than your individual poles:Imagine you create a hlaf ring shaped magnetic connection between the two blocks that also goes aruond the outer perimeter up to the outside of the magnets surface?I mean the surface facing the stator poles?Damn your imagination is good, yout it right away!Of course we would then have a magnet that allpies its full strength focussed onto each pole of a coil!And of course the resulting field would be far stronger than just using the magnet blocks itself and still significantly higher than just adding a shielding or connection between them.The affect of the next coil coming is also drastically reduced, which in return also increases the efficiency.In terms of numbers:If a fixed neodymium magnet would provide us 100$ field strength as the base point with no shielding (just the magnet blocks alone);A fully shielded and connected system, like in a hook magnet combined with a U-style magnet, would reach above 400% here.....Adding witchcraft to the mix ;)Although I know better I just assume some of you have now a working double-three-phase-ceiling-fan-generator.And that would mean you also have some fans to spare from your long experiments.Modern ignition coils seem to have nothing in common with our ceiling fan or resulting generator.So why do I try to use them anyway?For the ignition only one polarity is prefered so the spark works and travels as intendet.Means the "wasted" energy from the othe half of the pulse seems to be lost.The electronics do a lot here but magnets too ;)The core of the coil has magents at either end, turning it into one long magnet that still has the right properties to act as high voltage transformer system with the coils.The coil appear to be pre-loaded and with the ignition pulse it has to overcome the magnetic field pre-set by the magnets.And when the electrical impulse is off the same magnets also accelerated and increase the resulting fall back impulse - which provides the spark.Unless you have a suitable laser cutter or simlar cutting tech available somehow it will be hard to modify the metal plates of the stator.But if you could...Imagine you could add magnet inside the plates that are inside a coil.The same pre-loading would happen.Does not really help in terms of adding outpur as our rectifier would suffer badly here.It does give ideas though...Shielding works fine for the magnets, same for field shaping.Electromagnets use the same techniques...So why not use some leftlever transformer cores to add more "shortcuts" for the coils?Strips of transformer core sheets added either side of the coils increase their field strenght and result in better output!Three packs either side of the stator pack are usually no problem.Now take your leftovers and do a standard mod.Compare the max output on the same windmill with what you get from my mod(s).The only real magic I used here is that I actually bothered to combine multiple and already used methods to drastically increase the available output of an otherwise utterly useless generator mod ;)Warnings:If you take the above mods serious and to the their extreme than it is imperative to make sure you have safety measures in place!Assume the lowest rating for the magnet wire and if in doubt stick with a max output voltage of 800V.These mods are potentially lethal if you don't follow what is common sense to everyone dealing with high voltages for a living!Most people will start without any gearing or belts and use the wind directly.Even here it is easy to get far higher RPM than what the thing ever did under your ceiling.Without some fixes you will need transformers to reduce the output voltage accordingly.Only other option is to limit the max speed to what your DC-DC converter can handle.Making mistakes with mangets can cost you a lot of time and work, make sure to mark their poles somehow to prevent putting them in wrong.If in doubt then double check!Always keep in mind what the magnet wires and your connections can handle!You don't want any arcs or overheating.Some added electronics to monitor wind speed, rpm's, load and temperature of the coils can turn out vital once you upscale.Before letting your new generator do its thing make sure you tested all to the max!Use a drill or so to speed it up and check the limit regulation for the converters.Measure the actual volts and amps going through your coil sets at assumed max speed and max load.Monitor the coil temp while doing so to ensure nothing is out of limit!You are kidding me here right?A scrap ceiling fan shall provide more output as a wind generator than what was used to spin it as a fan?And of course I need not one but two 3-phse transformers...Pretty clear it is all a fake because nobody could replicate any of it unless limited to what the converters can handle...Didn't I say to think outside normal restraints already?A single phase transformer uses two coils in the most basic configuration.For example one side for 240V and te other for 12V.But some of them are more efficient than other ;)A 3-phase transformer uses 6 coils, two for each phase.And there are plenty of standrad transformer cores out there that would allow us to use this configuration.The worst being the MOT, or microwave oven transformer.Very lossy for a reason but good as an example as these have three core stems ;)Now that you see that you will that a lot more transformers actually allow you to replace the two coils with 6 ;)Ok, but why not use a rectifier first and not use a transformer or two at all?The resulting output voltage will without a gear REDUCTION be much higher than what a cheap DC-DC converter can handle.And at such speeds the effiency would be very bad too.You would need huge capacitors of good quality to deal with the now more impulse like output.And considering the primary side of the transformer does not require anything thicker than the wire on the coils of the fan...Not hard at all to find some suitable tansformers to salvage - or to use some nice ring transformers ;)No kidding around, just facts and possible options you might want to explore.Does that now mean I get free energy?Sure, if you mean you get the free nergy from the energy of the wind at no cost.No if you think a ceiling fan could ever power your house.Internal resistance, size and wire/connection properties set our limits.Not to mention that they are designed to be dirt cheap.If you are in a windy region and assume a realistic 300W minimum output from a 100W fan then adding more stage multiplies this.These fancy upright windmills are not just powerful but also would allow to use one modded fan either end.If big enough and with enough wind force throughout the year you could just add a second or third stage to ech end.With 3 on both ends the resulting output would then be suddenly 1.8kW per windmill....And all from scrap parts with only the costs for the magnets...No wind? Then use water....None of it? Get some greyhounds and build a big hamster wheel :)You get the general idea I hope...

Topic by Downunder35m 3 months ago  |  last reply 3 months ago