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  • EEVblog #42 – Exploding Capacitors in High Speed

    Posted on November 4th, 2009 EEVblog 23 comments

    Dave blows up some tantalum and electrolytic capacitors in front of his new 300fps Sanyo Xacti high speed camcorder!

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    • http://sdickinson.com/ Sam

      I remember my electronics teacher blowing up an electrolytic cap, shooting and cracking the perspex on the clock at the back of the classroom. He made a protective box not long after that for demonstrating to the students.

    • David DLC

      I was servicing an old cassette player (this was some decades ago) and the design had a zener in parallel to a capacitor, the zener burnt so the voltage on the cap was not protected anymore and it exploded hitting me on the eye, human body is amazing I didn’t see the cap coming, but my eye closed and it hit me on the skin and not inside the eye (lucky me). After a visit to the hospital and several days with big headaches and blurry vision everything turned out ok, now I’m more carefull than ever.

      • Timothy Tee

        OMG. Did your eye swell?
        Amazingly the capacitor did not fly into your eye. Otherwise your doc will need to perform a surgery. Not to mention, you will lose 1 eye.

        • David DLC

          It did a little bit, is like if somebody punch you in the eye.

        • http://www.eevblog.com EEVblog

          Yeah, something happened to my eye between takes, it went all red, that ain’t the new camera!

    • Michael Thompson

      Another bandage for our host please…

      Dave you rock!

    • http://kaqelec.dyndns.org Kathy Quinlan

      ROFLMAO I love this, when I was little around age 10, I used to run electros off the mains (with a 500w globe in serries to stop the 16A fuse from bowing), I would bury them in the ground about 6inches and it would shoot dirt up about 25 feet :)

      I once spent a week building a relay box (20 odd relays, 555 and a couple of counter chips, it would step to the next relay after a second or so) then wire up all the caps in the front lawn and make it a war zone ;)

      Very dangerous, but I had fun, I am still alive and have most of my body in one piece ;)

      I used to do contract manufacture for a local company, I would solder up all the PCB’s, then after I had about 40 I would run them on the test jig to make sure the product worked. I mounted a low voltage large capacitance electro in backwards, when I applied power, there was a bit of a hum, then a huge explosion, foil and paper everywhere… The can was hanging out the gyprock ceiling :) livened up a Friday afternoon, I think it was beer o’clock after that.

      Regards,

      Kat.

    • http://www.idea2ic.com/ Don Sauer

      Thanks…
      This subject has always been a fun part of the lab experience.

    • Lionel

      Hey Dave, your blog has hit the big time! Your exploding capacitor video has made it to BoingBoing!

      • http://www.eevblog.com EEVblog

        I’m obviously not with it, what’s BoingBoing?!

        • Lionel

          It’s a very popular website for cool stuff of a technical or artistic nature. Sorry, I thought that I included a URL, but it seems not to have shown up. I’ll try again:

          If that didn’t work, try going to http://www.boingboing.net, & search for ‘capacitors’

          Cheers! Lionel (AKA ‘Bob Larter’)

    • http://wa0uwh.blogspot.com/ Eldon Brown

      Dave,

      My Grandson had a few old electric toys that were powered by 9 volt batteries. The toys were out-of-favour and not touched for several year. He was cleaning his room and decided to take the old batteries out to discard them. Not knowing better, he clip the snaps together on the two of the old dead batteries.

      An hour or so later we heard a “snap” from the area of the trash can. We could not find anything to suggest a problem.

      About 30 minutes later; the trash can jumped about a two feet (along with the rest of us) from the loud explosion. The second battery unfolded itself all over the inside of the can.

      My Grandson and I now know better, and I watch what kids are doing with batteries and how batteries are disposed.

      I enjoy your Blog -

      Eldon

      -

    • Ray Jones

      I’ve always wondered how good a tantalum cap would be for lighting a camp fire.

      Reckon they’d be good value, stand back and throw the switch!

    • BoBoo

      Dont you have anything more constructive than this trash ?

      • Michael L.

        To David: You know you’re succsessful when you’ve got your first hater to post on your blog. :P

        • http://www.eevblog.com EEVblog

          I’ve had haters from Day 1, I love them, they crack me up!
          Curiously, they never show me THEIR video blog to show me how it’s supposed to be done…

    • http://monda.hu L

      When you record in your lab I can only hear high frequency sound which is slightly irritating.

      Couldn’t it be made better?

      • http://www.eevblog.com EEVblog

        @Laszlo
        Do you mean there isn’t much bottom end bass response in the audio?
        I don’t do (and don’t want to do) any post processing on the audio, it’s raw as it comes out of the external shotgun microphone, I don’t even normalise the audio level.
        Can you point to a particular example that is annoying?

    • http://truthspew.wordpress.com Tony P

      Great vids. And one hint, even we folks who are hobbyist electronics people should wear eye protection.

    • Jason

      Ah, love blasting capacitors. I had a 4700 uF capacitor under a yogurt cup and it sent the cup 10 feet in the air, not to mention sent a plume of smoke towards my neighbours’ BBQ.

    • Eh? whats that?

      Ya an exploding capacitor and really blow your day (pun intended) That being said the biggest scare I had was with a power supply I built and I had a big 1000mf capacitor for a filter this wasn’t the little dinky ones you see now days, this baby stood about 6″ tall and about 1 1/2 inches in diameter. What happened was I had inadvertantly shorted the output…luckily it didn’t boom it just sounded like a rocket trying to take off for about 10 sec. needless to say if it had blown I expect it would have knocked me on my keester at the very least
      Thanking my lucky stars….

    • Matt Gholston

      Not a capacitor, but just as fun… I was recently working on a piece of gear that contained a 12KV 5H Choke, which arced over internally and destroyed itself while we were testing repairs to another section of the device. When it exploded out the side, the force dented the 18 gauge steel cabinet that it was enclosed in and scared that he hell out of the guy that was working with me :) I don’t know how to post a picture here, but I have one of the damaged unit, pretty cool!