> Another failure mode is that it will stand the applied voltage for a time
> (a few minutes, or so) and then the thinned oxide film will break down,
> and the thing will short. I have seen this happen, and it's nasty because
> the capacitor tests fine to start with.
About ten years ago, I was using a 2 metre amateur radio power
amplifier, that had been in storage for a few years. It ran fine for
several days of intermittent use, but one quiet Sunday morning, as I was
excitedly working another amateur station via the moon (this was EME
operation where both hams use the surface of the moon as a passive
reflector), two electrolytics in the amp's power supply exploded, sending
a fireball and thousands of pieces of paper dielectric through the top of
the amp and into my ham shack.
Needless to say, the breakers tripped, and my contact was over. My wife
heard the explosion, came to the hallway, and asked "what was that??" She
still tells friends of my calm reply "Can you bring the fire extinguisher
up here, please?".
That afternoon, with a $5 expenditure on new electrolytics, the amp was
operational again.
Kevin
--
Kevin McQuiggin VE7ZD
mcquiggi_at_sfu.ca
Received on Sat Apr 24 1999 - 15:21:00 BST