Bob, About 30 years ago I was in a Basic Electronics lab and one of my class mates did exactly what you described on a breadboard . I was working on building a typical power supply with a bridge rectifier and a transformer which had a plug for the 110 side. I heard this big bang and looked over towards where the sound came from. There was a lot smoke and this awful smell in the air and a guy who looked pretty confused from what had just happened. He had put one of the filtering caps in backwards on the breadboard and it blew up and put a huge hole in his lab book and I think it ruined the bread too. Michael Johnston On Sun, Feb 25, 2018 at 8:54 PM, Richard Pope wrote: > Brent, > I don't think it is funny when people could or are being hurt. That > is just me. Funny to me is a cat hanging onto a pole 2 feet off of the > ground as he looks over the pole with this look on his face that says, > "OK, Now what do I do?". > GOD Bless and Thanks, > rich! > > On 2/25/2018 8:33 PM, Brent Brown wrote: > > Richard, sorry, my weak humour makes light of the safety concerns. The > last cap > > that did this near me was something like 2200uF 25V, a long time ago, > and I think it > > failed from temperature & ripple. Sounded like a shot gun. It was axial > leaded, don't > > remember if it had an X or not. > > > > Agreed, the X is there to relieve pressure... they certainly deform and > open in caps > > that swell & leak. Perhaps there are limits to their effectiveness wher= e > a fault > > creates a fast internal pressure rise closer to the other end. > > > >> Nope. That X is a weak spot in the casing and it is put there by > >> the manufacturer as a safety valve so that the capacitor won't go > >> ballistic if the capacitor should fail. What happened to Bob was not > >> supposed to occur. I have had Capacitors fail, including a couple that= I > >> have also put in backwards over the years and I have had only one go > >> ballistic. The others opened at the top. Those had gone pop as there > >> were pieces of the insides blown all over the place but at least those > >> pieces would not have been dangerous except for a few minor burns. > >> > >>> Perhaps it's a matter of interpretation. The X means "not this end", > and the arrows > >>> define the direction of thrust... ;-) > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > -- > 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 .