PDA

View Full Version : capacitors



Terry Yager
November 26th, 2003, 05:15 PM
Last night I pulled my beloved CCS system out of storage where it has been for the last 5 years. I brought it home, hooked everything up and applied power to it. BANG! BANG! BANG! It sounded like WW III was starting up. A hasty inspection revealed that a total of 8 tantalum capacitors had given up the magic smoke. My question is: What causes this phenomenon? Is it just because the caps deteriorate with age and can no longer handle the voltage going through them? ...or what???

--T

djkrex
November 26th, 2003, 06:16 PM
I had a similar experience awhile back. I connected an old paper capacitor (encased in plastic) across a 220 vac line for noise reduction.
It exploded so loud that it made my ears ring. Big pieces of plastic and tin foil everywear. My guess is that old caps, when they get leaky, they develope a resistive leak between the plates. This causes heat and produces gas. If the cap is sealed in ceramic, it will pop like a fire cracker. LED's and glass diodes make a nice snap when you put too much juice to em.

Terry Yager
November 26th, 2003, 06:30 PM
Heh heh, reminds me of the time I blew up the coil on my old roadster. (Never run 24 volts thru a 12 volt part.) That sounded like a stick of dynamite inside my garage. I think my ears still ring from that one!

--T