[TenTec] swapping a tantalum...

[N9TZL]

I would disagree that "protecting the external circuit referred to, and not the cap.(?)" I still think it is to protect the cap :)

Still stand by my statement "I agree it can be done in some places just be careful." I might change some places to many places though; you just need to have an understanding of the circuitry connected to the cap and what the cap is doing there.

There is allot if info out here in the web and here is another reference with a chart of some CAPACITOR SPECIFICATIONS AND TRADE-OFFS, although it does not mention the inrush or ripple current specs for Tantalum caps. Interesting comment on Tantalum caps in audio circuits in there also.  

http://www.intersil.com/data/an/an1325.pdf

Stuart had some good input in his email also.

73, Dennis N9TZL


----- Original Message -----
From: Roy <royanjoy at ncn.net>
To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
Sent: Tue, 24 Jan 2012 11:51:25 -0600 (CST)
Subject: Re: [TenTec] swapping a tantalum...

Not to be a killjoy but: Personally I would be careful in the wholesale 
replacement of electrolytics with Tantalum caps. Tantalum caps can not stand 
the inrush current that electrolytics can which can cause the Tantalum cap 
to fail. They require some series impedance from the voltage source to the 
cap so as not to exceed the inrush current.

I agree it can be done in some places just be careful.

Couple of references!

http://en.wikipedia.org/wiki/Tantalum_capacitor

http://www.hitachiaic.com/docs/products/tantprecautions.pdf

73, Dennis N9TZL

Dennis,

I take the below statement to possibly pertain to protecting the external 
circuit referred to, and not the cap.(?)

73,   Roy     K6XK



"Tantalum capacitors have a relatively low effective series resistance (ESR) 
when compared to equivalent value aluminium electrolytic capacitors. Because 
of this, care must be taken when designing a circuit using tantalum 
capacitors to limit charge and discharge currents (particularly those of a 
repetitive nature) to a safe value. " 


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