I recently took apart an old stereo reciever that didnt work anymore. As always, I salvaged as much stuff as I could, and came across 2 huge capacitors. They are each about the size of a C- batery,and are rated at 50v, 6800 uF. I, of course, saved them, but now I cant think of anything to do with them!if anyone has any ideas, please let me know stat.

Posted by tigerdog330 10 years ago

about capacitors

I understand that capacitors store electricity, but what controls them. what lets them discharge?

Posted by kendallickes 9 years ago

Need Capcitors

I Need Capacitors Bad!!! Any Size.

Posted by wolf996 6 years ago

Big Capacitors

I found a big capacitor in a floor cleaner...I think. It is a black cylinder with two leads off the end. In the floor cleaner, it was hooked up to a lot of stuff in a really important looking box that had a lot of wires flying everywhere. It looks sort of like the thing below, but a little smaller. So, really, there are two questions: 1. Is it a capacitor? 2. If it is, what can I do with it? Thank you!

Posted by basementhacker 5 years ago

Anyone have any capacitors laying around?

Hey, I'm doing some electrical engineering projects and I need some capacitors. Anything flash-capacitor-ish sized or bigger is best. Thanks, Ben

Posted by Ben Mighall 5 years ago

Quick coilgun Capacitor question

Im using chargers to rank 330V or even 370V. Heres my options. 400V 330uF Capacitor 450V 150uF Capacitor Im guessing the 330uF, But what's better for a coilgun? (using 4 of them in parallel, yet buying 10.)

Posted by Killa-X 9 years ago

microwave oven capacitors for sale

I have some microwave oven capacitors and  transformers that I would like to trade or sale. Iam interested in radio parts ( crystal head phones, vacume tubes ect.) I just don't have money for shipping

Posted by inductionheat! 8 years ago

Can any body identifie the Capacitor

I have a DVD play I'm trying to fix I found the Capacitor blow out. Can any body tell me what the spec are on this Cap. All the info on the cap in on the first Pic's the second pic' is a pic of the cap.

Posted by Bernie777 2 years ago


I am trying to turn 3v dc into 300v dc to charge some capacitors I plan to use to make a coil gun. Any way I can do this cheaply and relatively easily would be a huge help!

Posted by J55862 10 years ago

Charging camera flash capacitors from mains supply

Hi everyone, I have a quick question about charging some capacitors.  I'm trying to make a very simple ignition system using capacitors from disposable camera flash circuits.  I'm planning on using maybe 5 or so.  They are rated at 330V and 120uF.  If I were to hook them up in parallel, so that i have a total of ~600uF, could I use a full-wave bridge recifier diode to turn the AC into DC and simply charge it like that without anything else in the circuit.  I don't know how to explain this very well so I attatched a schematic so you can see what I'm talking about.  Any help is much appreciated.. P.S. Ignore the fact that the full-wave rectifier looks messed up, doesn't have a f-w r symbol.  Thanks again!

Posted by BCSTechie 5 years ago


Hi there. While testing some code on three servos using my picaxe 18m2 project board I initially had them powered of the 4x1.5v battery pack. This was working smooth enough, but because I eventually plan to power seven servos (for a robot arm project) I thought I'd try using a 7.5v wall transformer but they didn't seem to like this as the smoothness of movement was gone as they slowed and sped up and were jittery.  Is the 7.5 a bit much, a few resistors maybe? Or prehaps capacitors would smooth things out. I'm not overly electronically gifted, robot builders guide is all I've got to go on. cheers. john. 

Posted by jonnymelon 5 years ago

help i need information on capacitors

This is a call for help I need all the basic information on using capacitors. Especially how to charge them, and discharge them. I need to know so I can post my first Instructable.

Posted by pgd5000 9 years ago

Distortion pedal project

I was planning on making a motion detector with my roommates but that proved a difficult first project so now we have the plans for a distortion pedal for guitar.Here is the design for it and here is where we are going to buy the equipment (except for the audio jacks which we bought at Radio Shack already).Here are a couple of things we need to know first:1) The plan calls for two 10uf electrolytic capacitors, and the store has those but of 5 varieties with different voltages, which ones should we get?2) What kind of capacitors do we need? Ceramic disk?3) The plans call for a 0.0056uF capacitor yet I couldn't find one like that, can I just substitute one similar? If so, which one?4) If anyone wouldn't mind, could someone explain how this circuit works? Preferably answer the other questions, but I would like to learn how it works also.Thanks a lot to all who answer!

Posted by gohuskies 9 years ago

Can I replace electrolytic caps with tantalum?

I'm thinking of replacing some electrolytic caps with smaller ones to save space. Foresee any problems? I was thinking tantalum just because they looked like they might be smaller. This is for a AAA 1.2-1.5V circuit.

Posted by royalestel 10 years ago

Are these Capacitors Fried??

I think i blew out a cheap voice chance I have... can anyone verify that the capacitors I have circled are indeed blown... I've never looked before, and am not 100% sure the black isn't just a manufacturers marking. also, the caps are 20pF and 56pF and I need to replace them STAT... would Radio Shack's 100 pack capacitor grab bag have these numbers?

Posted by gschoppe 10 years ago

do capacitors like this work?

Do capacitors like these:|65%3A15|39%3A1|240%3A1318work in applications like voltage multipliers, marx generators, etc. Or are they meant for something else? They seem like a really good deal and I just don't want to buy a ton of them to fail on me in like 2 seconds.

Posted by guyfrom7up 9 years ago

Polarity of tantalum capacitors

Howdy all, Recently got back into basic electronics and have started building kits. Been building a kit that uses tantalum capacitors and it notes that polarity orientation is very important. The question I have is: is there some un-published indicator of how polarity is indicated on these tantalum caps? I've been over these things with a microscope, even bought new ones, but other than the values & manufacturer, I can find no obvious sign of polarity. Leads are the same length and not marked. What am I missing? Thanks in advance for any help. Dave

Posted by gutbucket 6 years ago

Disposable Camera Hack?

Hi, im building a capacitor bank for my coilgun, and I have 17 disposable camera capacitors in them. (wired in parallel (or whatever one means + is atached to +, and - is atached to -)) But for some reason wenever I start chrging it, after a little wile, it makes a huge spark across one  of the capacitors. That probobly means its arcing right? but its only 300 volts (there wired in parelell so only the amperage goes up, not the volts).  I then tryed to charge the caps to a point before they arced, wich took about 1 min (the battery is full) and my ammo only shot 3 inches! 17 capacitors, charging for 1 min, and it slid across the floor 3 inches! I have no idea what im doing wrong. Im using wire from a microwave motor  (wich is realy small) for the coil, and its 5 layers thick, wrapped around a hollowed out pen. So, to sum it all up, here are the main problems: 1) the caps arc when charging 2) the ammo only goes 3 @#%!ing INCHES!!!!!! arg! Ps, i heard someware, that if you have enought amps, it will arc even with lower voltages. Maby thats whats happening?

Posted by Stuffses 8 years ago

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, does my setup look feasible ?

Posted by tazerboy 6 years ago

Voltage Regulator circuit

I am trying to power Bluetooth module and the Arduino using a 9V battery. So tried to use a voltage regulator (KA7805) with 25volt 100miro farad and 63V 1 micro farad capacitors. I checked the circuit connecting these components using multimeter, it showed 5.06V as the output. But the problem comes when I connect the Bluetooth module to this output, which turns off after quickly. I checked the voltage at the bluetooth which is reducing quickly from 5V-2.5V in a matter of seconds and since the operating voltage of Bluetooth module HC-05 is 3.6V-7V, it turns off. I am not clear why this circuit behaving this way. Same output when I connected to the Arduino, it works seamlessly. Please let me know what are the mistakes that I need to rectify for this work. Thanks in advance

Posted by Bhanu Kishan 3 years ago

substituting capacitors

I was designing a board that uses a bunch of the same chip and all of the inputs require a capacitor. For example lets say I have 10 identical chips with identical setups. Instead of having individual capacitors for everything to ground (except for the outputs) can I combine all of the ceramic capacitors and use a couple of bigger electrolyctic capacitors? So lets say I can have 1 capacitor for all of the identical inputs instead of 10 smaller ceramic ones. But for stuff like timing do I need individual capacitors?

Posted by guyfrom7up 10 years ago

Arduino high voltage capacitor charge indicator?

I made a 330v gauss gun and wanted a way how to know when capacitors charge, at first i took an led and resistor, that worked but is kinda boring. I want to use arduino and lcd to display percentage which should look more cooler. How should I measure the capacitor bank voltage with arduino? Should I use voltage divider? or there is a better way?

Posted by spudziuvelis 2 years ago

People and Compact HIgh votlage capacitors

This is just a little anouncement. To all you people making coilguns and micro tesla coils and other highvoltage devices that require a rather large capacitor (and this goes to all circuits) and who try to save space to make a smaller, sleeker design (no one wants a bulky coilgun). 1) DO NOT put capacitors in series, just buy a capacitor on ebay that can withstand the voltage. about 90% of the time (I have only found one occurence where I got a smaller package for putting capacitors in series) you are wasting about half (or even more) of the volume. When you put capacitors in series, effectively you are just doubling the dielect width, and just wasting a lot of the conductor room (inside the cap, forgot the name) because it's not being used!!!! 2) Put Capacitors in parallel. Most of the time 10x 1kv, 1uF caps in parallel (1kv, 10uF) will take up much less room than 5x 200 volt 5uF capacitors in series. 3) I'm not sure if you can understand #1, if so, my bad. Basically you waste somewhere between 20 and 80% of the space, depending on how many caps in series you have. Just felt like throwing this out there because I see so many inefficient designs...

Posted by guyfrom7up 9 years ago


post in the comments your coilgun, capacitor bank, and how your coilgun works. I want to know everything about it. EX: how long your coil is, how many layers your coil is, how you built it, etc. The more you put the better. I also would like some advice on my new coilgun I'm building. I want to use flash-capacitors and 26-gauge wire. I don't want to use a lethal amount of electricity if at all possible. Thanks!

Posted by Pyrofan 7 years ago

Looking to make a new coilgun, need answers

I was going to start a new coilgun now that i've learn more about the coil it self (last one shot 3 inches , bad coils!Whats the best capacitors to use? - How many volts and UF? - Where can i get them for a cheap price?What tips do i need to know to keep the capacitors safe, as long with me (besides DONT TOUCH CONNECTIONS WHEN ITS HOT!) lol....I can use camera flash circuits to charge the caps, just don't know whats best to get :(

Posted by Killa-X 10 years ago

LG monitor has faded picture and then goes black

Hi, I’m experiencing problems with my LG Flatron Wide. The screen comes on with a very faded picture and then goes black. I assumed that maybe the capacitors (like for others) needed to be changed. However, I have opened the monitor and the caps look perfectly fine, no bulges or anything. Does anyone think I should just go ahead and try changing the caps anyway? Or could anything else be wrong? Thanks a lot.

Posted by Chu Guk 6 years ago

capacitor control

I was just wondering if anyone knows any methods of controlling the energy discharge from a capacitor..

Posted by nuncoop 10 years ago

Help with charging capacitors

How do I charge my 450v capacitors with a 120v outlet? I am building a rail gun and need to get these up to a high enough voltage. 

Posted by gclark0812 11 months ago

Cheap Source of high votage capacitors

Anybody have any ideas where i can get high voltage capacitors for building a capacitor bank?

Posted by Marche 10 years ago

capacitor based battery replacement

I was wandering how big does a normal capacitor have to be to replace a AAA battery?

Posted by clasic_traveller_diehard 10 years ago

Recently aquired a BIG capacitor

I need some ideas to use this capacitor for. the ratings are 120,000 MFD @ 25 VDC Thank you.

Posted by newwarhammer2 6 years ago

Capacitor Pin Extention

Good day everyone, I am sitting with a issue of changing a capacitor on a board but the factory default pins are to short to reach their holes. Is there a way to make them longer other then needing to get another new capacitor? I am using a 450V 150uf(M) capacitor. 

Posted by ChristopherC297 1 year ago

single lead capacitor

How can i make a single lead capacitor for this

Posted by taterkiller 8 years ago

capacitor resistance

Why is it that as super capacitors capacitance goes up the internal resistance goes down? I'm looking for a tiny capacitor that can supply 0.3 volts20mA (I'm going to be powering flexinol, not an LED) for 1 second. I don't want the capacitor to be huge because I'm making a beam bot where size is a factor for charging time and because of it's physical size.

Posted by guyfrom7up 10 years ago

how do a 1.5v battary charge 330v capacitor in a disposable camera?

I got a capacitor from my disposable camera but it was damaged so i buy a 330v 120uf capacitor but i cant charge it on my 1.5v battary i wont to know how do a 1.5v battary charge 330v capacitor in a disposable camera

Posted by omartech 4 years ago

How to read the value in farad of this capacitor?

Hi,  This is from a 1964 function generator and the capacitor of now "dry". Its maked as: ----------------------- SPRAGUE FILMITE "E" CAPACITOR 10.0 - 30 DC  127P1069R3S4 MADE IN U.S.A ------------------------ There picture is not THIS ONE, but its pretty close (of the big one) i would like to now what is the value of my capacitor. (10.0 - 30 DC) Is it 10mF? Thanks

Posted by johnybody 6 years ago

Identify ceramic/film capacitors?? what?

So i went on this website, because i need a 1.0uF ceramic capacitor. would the numbers be 105 and a letter?(there doesn't have to be a letter, but there may be)Thanks!

Posted by Sandisk1duo 10 years ago

Explosive Fun with a Capacitor Bank

Watch a 24kj capacitor bank as it discharges through various objects. Maniacal laughter follows each one and a slo-mo montage finishes it all up. via Make blog

Posted by fungus amungus 9 years ago


Hey, selling a massive box of Cap's.... see here if interested;;=151394654697#viTabs_0 Thanks!

Posted by 75lockwood 3 years ago

What can I do with 49 47uF Capacitors?

I needed a 47uF 35v capacitor for a project and ened up buying 50 of them for like a dollar. I don't know what to do with them.

Posted by Clayton H. 8 years ago

uF difference interchange capacitor question

Hello everyone! I got a microwave, Sharp R21LCF with a bad capacitor. A friend of mine used to have the same Sharp microwave, but older model, R21JCA. When his R21JCA broken and could not be repaired; he took out the parts that still work and save them. So he has a spare capacitor. I compare both capacitors and found his good capacitor has a 2400VAC with .94 uF comparing to my bad capacitor, which has 2300 VAC with 1.00 uF. I understand that you can replace the capacitor with a higher voltage rating, but not sure if .6 uF difference would be ok for replacement? May i ask for your expertise opinion/input? Thank you very much for yr time! attached are the two links for those capacitor I am asking about. Bad capacitor from R21LCF Good capacitor that we want to use from R21JCA

Posted by didadee 5 years ago

Help with capacitors

Hello everyone. I've seen this instrucable ( that uses a charged capacitor to light up a LED.I found this very interesting, so I started investigating what a capacitor is.So far so good and my questions are:- Can capacitors be used as replacements for batteries? I'm thinking specifically to light 1, 2 or 3 LEDs.- If so, how can I calculate the specs of a capacitors for a determined amount of LEDs.- Is it possible to calculate how much time the capacitors will keep the LEDs lit?- How can I determine if the capacitors have enough charge to light the LEDs?- Would you be kind enough to suggest a circuit to achieve any of these?Thank you.

Posted by transistor 11 years ago

Welcome to Super Capacitors!

First off, I know this goes to the whole front page, but this is posted in the Super Capacitor group, just so you know. Welcome to the people who joined my group! If anybody has any cool projects or ideas, please post and talk about them! Also if you know of any good deals for capacitors, please tell!

Posted by guyfrom7up 10 years ago

How Should I Organize Electrical Components

Like most electronics hobbyists, I have hundreds of different tiny electrical components lying around.  I've been looking for a simple and relatively compact method of organizing them, but I can't find any that I like.  Any ideas/suggestions?

Posted by jimmy dean 7 years ago

HV capacitor bank charge indicator?

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

Posted by SirCheez 5 years ago


CAN ANYONE HELP ME ABOUT HOW TO PUT A VOLTAGE/CHARGE INDICATOR on flash/High Voltage capacitors using LEDs - Thank You.....!!!!!!!

Posted by KITKAT69 10 years ago

are these really capacitors?

Http://'m only asking because either the manufacture doesn't know what they're talking about or it's a battery with it's capactance measured in farads. The say rechargable capacitor. That's the only reason why I feel causious

Posted by guyfrom7up 10 years ago

Build a capacitor (proper dielectric)

Hi there, I need dielectric with very high "Dielectric Strength" (a few 10s or 100s of kilo volts per mm) and also high "Dielectric Constant". Can anyone suggest me one? I would like to build a compact capacitor with high capacity and I need advice how to do it. I would be happy if someone can help me and for that purpose I will describe what I need: - The capacitor must be "Parallel Plate Capacitor". - The capacitor must be very thin with small distance between the two plates. - The dielectric must have very high "Dielectric Strength" (a few 10s or 100s of kilo volts per mm) and also high "Dielectric Constant". - The capacitor will be connected to a DC current circuit which purpose is to charge the capacitor and to keep its charge sustainable in time. - The capacity of the capacitor must be a few micro Farads. Taking into account the above, there a few important questions (correct me if I am wrong): - What dielectric to use and where can I buy it? - Is the building of such capacitor achievable in home environment or there are manufacturers who can do it for me? - Is there anything important for the building of the capacitor which I have missed to mention? Thanks a lot! ;)

Posted by paveltashev 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?

Posted by merlinj 2 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.

Posted by darthDIY 8 years ago