I finally got around to electrolytic "field-expedient" grenades a few years ago - 10 uF 50V tantalum, plugged into a breadboard (inad- vertently). Very impressive - Possibly a lot more impressive with a stiffer Vcc... ... On 2/26/18, Dwayne Reid wrote: > Hi there, Bob. > > My experience is that if you do what you did, the capacitor will > often eject the can from the remainder of the capacitor. > > Many years ago, one of my buddies worked at a shop that did car audio > device repairs. The most common failure they had at that time was a > 10uF 25V capacitor. These failed by the dozens of non-working units - pe= r > day! > > In the far corner of their shop was a ceiling-mounted PA horn that > was universally despised by everyone. My buddy took an old 24Vac 15 > or 20 Amp transformer and attached sturdy wires with alligator > clips. He then set up a mickey-mouse mortar tube made of brass - > this was semi-fixed in place but adjustable. The tube was just > larger in diameter than these 10uF capacitors. > > 24 Vac with essentially an unlimited amount of current will cause > some very nice thermal events to small electrolytic > capacitors. Namely: a decently-loud BANG followed by the aluminum > case being ejected quite forcefully! > > Everyone took turns using this rig to fire defective capacitors at > that obnoxious PA speaker. > > Anyway, this has stuck in my mind for eons now. Bottom line: assume > that the can will be ejected should you do something really bad to > electrolytic capacitors! > > dwayne > > > At 06:36 PM 2/25/2018, Bob Blick wrote: >>By mistake I put an electrolytic capacitor in backwards. A very >>generic 100uF, 50V cap exposed to 16V with the equivalent of about >>700 ohms in series with it. It lasted about 30 minutes, then went >>off with a bang. You can maybe see the damaged heatshrink where the >>can hit an immovable object. >> >>Please note the scored cross on the top of the can. Isn't that >>supposed to split and protect me from its rapid self-disassembly? >>Yes, I was right there, close at hand, trying to figure out why all >>the voltages were wrong. Perhaps their die for the venting "X" was >>worn out after 20 million caps. I guess that's what I get when I pay >>USD 0.03 for caps off of Aliexpress instead of USD 0.11 at Digi-Key :) >> >>I guess I learned a lesson in false economy today. I didn't lose an >>eye, but I'm going to change my buying habits a little. Obviously I >>made a mistake putting the cap in wrong, but if I'd used a quality >>cap perhaps I'd have only been startled with a scary hiss instead of >>a projectile. Take heed! How many lives do you really have? >> >>Cheerful regards, >> >>Bob > > > -- > Dwayne Reid > Trinity Electronics Systems Ltd Edmonton, AB, CANADA > 780-489-3199 voice 780-487-6397 fax 888-489-3199 Toll Free > www.trinity-electronics.com > Custom Electronics Design and Manufacturing > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .