Electrolytic capacitors that explode

Discussion in 'Supporting Physics' started by hadley, Feb 13, 2020.

  1. A strange request this morning to source some "unsafe" Electrolytic capacitors, ones that explode. Does anyone happen to know what ones/where I can buy these? :confused: For use to demo, inside a safe box of course
  2. I do this, I cant remember where I bought them from, but I bought the 85degree C version at a low operating voltage 10V then stuck them on a 20V supply reverse biased.... Bang.
    hadley likes this.
  3. Nick Mitchener

    Nick Mitchener COMMITTEE

    We have some SATZ power supplies that do that
    chris vaudin likes this.
  4. 'ELF & SAFETY

    Do NOT do this - you do not know what chemicals are in them!

    I have seen the hole in the ceiling produced by an exploding electrolytic capacitor. 400V was inadvertently applied to 200V capacitor. It bent a substantial metal bracket before flying past the technicians ear.
  5. yes just do the giant tinfoil one with the HT supply, more fun

  6. STEM1

    STEM1 Dave

    Most will explode if you mistreat them. Excess voltage, reverse voltage etc will cause them to gas and then the can flies off or ruptures. If you really want to do this, use the smallest low voltage ones you can find. I used to hang them out of the window at home when I was young and foolish. Neighbours thought I had a gun!
  7. That video: Paul #7 takes me back - nearly 50 years in fact. I had designed a 5kV power supply for a company that manufactured products for Griffin & George. I was invited to take the prototype for approval by a physics teacher. We went one evening in the dark but I now assume that it was to visit Geoff Foxcroft at Rugby School. He took my power supply and connected it up to two sheets of cooking foil separated by a piece of black bin liner. He turned out the lights and gave a very spectacular demonstration of the capacitor discharging through a weak point in the plastic, making a spark which burned a hole in the metal, before moving on to find the next weak spot.

    I was watching this with some trepidation, thus my lack of concern about my surroundings. The capacitor eventually developed a permanent short circuit and the experiment ended with my power supply still working.

    The 5kV supply was a rubbish design and was done when I was young and knew everything. The only good thing about it was that it was safe. I think at least some of these were made but I have never seen one since.

    Sorry to go off topic.
  8. Any idea what the model was? Some of us have big storage cupboards full of "more mature" equipment....