[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Use of Tantalums - DRSSTCs



Original poster: Esondrmn@xxxxxxx

In a message dated 12/7/04 3:18:56 PM Pacific Standard Time, tesla@xxxxxxxxxx writes:

Hi,

Tantalum capacitors are known for not being terribly reliable.  They are
very finely made and if there is any contamination they will fail in the
future. Now a days, they are getting pretty good at making them
however.  In high current applications, they can catch fire and burn up
which is a real problem.

In the case of Dan's controller board, the tantalums failing are the very
least of "my" concerns though ;-)))  I will blow everything else up long
before the tans decide to fail for whatever reason ;-)

Cheers,

Terry


Back when I was in the Electrical Engineering business, we used to design tantalum caps into all our circuit boards as 5 v dc power filters. I think they were 10 ufd 35 volt caps. They had a small red dot on the + side. Sometimes they were mis-marked by the supplier and sometimes our production facility would just install a few backwards. It seems that they would work fine for 10, 20 or 30 minutes - just enough to test the product and ship it out the door. Then after some time in use, they would self distruct, causing a direct short across the + 5 volt supply. Lots of smoke, burned up circuit boards, etc. Even if they were installed properly it seems that a small percentage of them would eventually short. We had a difficult time finding reliable suppliers of these tantalum caps. Things have probably changed a lot - that was about 25 years ago. They seemed like little time bombs just waiting to go off. Some of our customers would not allow us to use them.

Ed Sonderman