Blowing up capacitors

[grenadier] wrote in to show us a video of some capacitors being blown up. Yup, that’s it. Just some capacitors being blown up. You might be wondering what there is to learn from this video. The answer is… nothing. It sure is fun to watch though. We’re all busy trying to find some nice hacks to share with you, so we figured you could watch some stuff getting destroyed while you waited.  Here’s someone using explosives to reveal art behind a thin layer of concrete on a wall. Here’s some high voltage destroying multimeters. How about a turkey being cooked with thermite? Thermite works on hard drives too.

Ok, enough of that. This was a gentle reminder to send us tips to your projects.


  1. Alex says:

    I enjoyed dumping my 330J 170V capacitor bank into the pencil-eraser-sized electrolytics from old computer motherboards. They went off like firecrackers. That was a lot of fun.

  2. 2000nits says:

    I used to do this all the time. Guess I need to do it again!! Fun after work today!

  3. Debraj says:

    That proves, not all capacitors are not explosion proof..

  4. hunternet93 says:

    Magic smoke! That’s where it comes from!

  5. beemer says:

    Yes, you can learn that inverting a electrolitic cap polarity or exposing it to a highger voltage is not a good idea and you should be careful…

    May caps blowned in the laboraory when I was at school ;)

  6. Will says:

    Ok, this just upsets me now. I have sent in a set of quality projects TWICE now and have watched it get pushed aside for crap like this. Not saying I don’t like to watch capacitors blow up, but thats not what I come to this site for.

    Project 1: using a microcontroller to turn old ADB tablets into usb

    Project 2: Making a usb Cintiq out of an old tablet pc screen

  7. K!P says:

    using a microcontroller to turn old ADB tablets into usb

    really? last year trew a couple out :( was hoarding them for years…

    also: magic smoke can no longer hide!

  8. BLuRry says:

    All hail the magic smoke! You know, you’ll never get it back in there now. First discovered magic smoke plugging in a floppy drive incorrectly on my apple //. Heard a loud BANG… and GAWD what a smell!

  9. fartface says:

    More fun was flipping off the teachers switch to all the lab desks in the EE lab, then loading a couple of the outlets with the Styrene caps (They go BOOM!) so when the TA comes in they get a nice big BANG from them flipping the switch.

    That and being bored and charging all the caps in the drawer for the next guy…. reach in and OW!

  10. DudeGuy says:

    Wow… I thought I was the only one who said that electronics ran on magic smoke. “Don’t let the smoke out”. Freakin weird. Did that come from somewhere or did we all just come up with the same idea?

  11. lwatcdr says:

    Slow news day I take it.

  12. Velifer says:

    No, DudeGuy, it’s just you.

  13. Dino says:

    Well, I sent HaD links to my last two… ?

  14. jwstolk says:

    I can still remember the smell….

  15. SpiralBrain says:

    Well! everyone needs to have some fun, so stop moaning!

  16. kad says:

    The video may teach you that when movie characters say “reverse the polarity”, it isn’t always a good idea to do so.

  17. Drone says:


    Wow, hacking old ADB compatible tablets (e.g., Wacom) back to life with an ADB/USB bridge and making overpriced Cintiq (Wacom again) devices out of hacked parts. Good stuff.

    Too bad Hack a Day isn’t really about hacking these days. Sorry to hear your submissions were sidelined. Maybe the HaD kids figured there would not be enough interest to post your work (not enough page view which equals Ad money). Hmmm…

    Anyway, give us the links to your work. Hopefully HaD won’t block them.

  18. Ginge says:

    I have submitted a couple of projects this year, also ignored. I’m not saying the hacks were awesome, but they beat some if the crap we see on here

    • Caleb Kraft says:

      @all complaining about sending in hacks that didn’t make it… THANKS!

      While there is plenty coming in, I just wanted to share this video and be goofy, I’m also going back and finding cool stuff that got lost in the shuffle.

  19. David says:

    We did this once at a company I used to work for. We were testing non-explosive propellants for ammunition (ie – not gun powder, or volatile propellants). Our goal was to build a weapon that could travel on commercial airlines (for the government of coarse) without explosive hazards. When you put a small electrolytic to 120VAC mains, it was like a fire cracker. HAHA Bigger one just mostly fizzled. Darn you 22,000uF!!!

  20. Mattster says:

    When I went to NE TEch, they turned off the breakers to the classrooms end of the day. One of my classmates went into the storage and put a 100 micro farad cap in every outlet (8) of every powerstrip (20)so when the breakers went on it sounded like a gun fight. We laughed but the teacher wasn’t amused

  21. Anon says:

    Fuck you, that’s why!

  22. Matt says:

    I know it says I can’t learn anything from this video, but I am going to try.

    Why would reversing the polarity on a capacitor make it blow up? That is something I have never understood (I only have a basic two-plate physics model for capacitors, which have no bias).

    Also, if you very slowly charge a capacitor up beyond its limit, does it also explode; does it cause dielectric breakdown or something?


  23. Will says:

    @Drone: Not my work alone, I’ve been working with a talented group of people on the Bongofish forums one member, Bernard deserves most of the credit. Here are some of the relevant links:

    (jump to page 6 for the final result)

  24. macona says:

    Tantalums are more interesting when they pop. Usually a slug of tantalum goes flying, red hot tantalum, that is.

  25. Well, one thing you can learn is if you have maybe a high voltage project with a bank of large capacitors, it’s probably a good idea to put some shielding between the user and the electronics.

  26. Drone says:

    @Will, thanks for the links. I’m looking now.

    @Caleb, Thanks for picking up on the issue of submissions not getting posted. Often the best stuff is in hidden in the rough. Knowing how to recognize it is the key.

    • Caleb Kraft says:

      Thanks but I haven’t resolved it. You see, we get TONS of emails and none of us hold regular office hours. Stuff simply gets forgotten/claimed by someone who ends up not writing it/ etc. If your project doesn’t get plopped onto the site soon, hit us again and again until someone gives you a reason.

  27. J. Peterson says:

    Hmm, the axial caps seem to blow much more vigorously than the radials. Are radials safer?

  28. Brennan says:


    Why would reversing the polarity on a capacitor make it blow up?

    It varies depending on the cap – different technologies have different failure modes. For tantalum caps, AVX says: “Under reverse voltages, experimental evidence within AVX indicates that a component of the reverse leakage current flows in very small areas of microcracks or other defects in the dielectric layer. Although the current may only be a few microamps, it represents a very high localized current density which can cause a tiny hot-spot. This can cause some conversion of amorphous tantalum pentoxide to the more conductive crystalline form. When a high current is available, this effect can avalanche and the device may become a total short.”

    Also, if you very slowly charge a capacitor up beyond its limit, does it also explode; does it cause dielectric breakdown or something?

    What do you mean exactly by “charge a cap up beyond its limit”? When you apply a voltage to a cap it charges to that voltage at a rate based on the time constant. Really the only way you can “overcharge” a cap is by applying a voltage that is significantly higher than it’s rated voltage. That’s really easy to avoid – just get a cap with a high enough voltage rating for the voltage you are applying. Generally what happens if you apply too high of a voltage is chemical reactions can occur that eat away the plates and punch holes in the dialectric, which causes a short and high current/power.

  29. OMGLOLZ says:

    So wasting capacitors and filling landfills with their toxic residues is a hack?
    Hey, I’ve got a hack too: how about dumping mercury into a gutter? That’s hilarious too, the fish all go belly up!
    And if seeing things blow up makes your day, just look for Semtex or RDX on YouTube. Or get a life.

  30. DarkFader says:

    Who needs capacitors anyways when you can have an arduino?

  31. Mike says:

    “Why would reversing the polarity on a capacitor make it blow up?” It literally says this right on the page above the video on the teravolt website.

    If nothing else, at least this shows that the venting slits on top of capacitors do work.

  32. Decius says:


    I was thinking the same thing, anyone with half a brain could tell you this isn’t something very suitable for the outdoors.

    Here at hackaday we save electronics from going to the landfill and then we even the pollution by blowing off smoke from capacitors.

    I wonder why this person was doing it outside? Surely you can blow these off in a closed room with the windows closed, the smell is like brand new electronics who doesn’t like to inhale that stuff?!?! /s

  33. Frogz says:

    there isnt many geeks who DONT like blowing up capacitors(besides 1s who have never tried it)
    i personally use a little butane torch on old boards directly on the caps(with a little hand shielding to prevent injury)
    they give a nice little pop without overloading them electrically :D

    also, they produce confetti when they go pop!

  34. salomon says:

    I learned how to build little smoke grenades! lol

  35. Microguy says:

    Almost went to jail doing this one time. Found out it’s illegal to have “fireworks” in Georgia (back then). Hard a heck of a time convincing the cops that those little firework looking, and certainly sounding, things were NOT actually fireworks!!

    Then later, some kid we worked with found out that by inserting the 10uF size caps into a small plastic tube that some parts came in, you could create a “capacitor cannon”!! Loved it! Wernt through lots of caps though, hard a heck of time getting him to stop wasting parts!

  36. Unclegummers says:

    Man I almost reached for my safety glasses just watching this video. Great vid.

  37. M4CGYV3R says:


  38. tooth says:

    if you do not like to see different things like cap popping or “this is not a hack” stuff then stop coming here and whining its annoying. Your not in the spirit of hacking. i would suggest for you to watch a documentary called “The History Of Hacking”
    Google it. if you never seen it its a grate watch.

  39. Mex says:

    Am I the only one who feels nervous when they see that much magic smoke even out of context?

  40. kabukicho2001 said, says:

    that smoke can be very toxic . stop that one.

  41. NormPH says:

    Oh memories… One day, our grade 12 comp engineering prof was away and thought us responsible enough to manage without a substitute… so we proceeded to waste the time ripping caps out of old motherboards and blowing em up with large power supplies, we even made a little detonation zone and everything… Oh memories…

  42. tripointlogic says:

    AWWW The Smell !!!! I have done that inadvertently on a tube amp power supply…

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 96,710 other followers