>>> Be aware that in a hot environment, the lifetime of wet 
>>> electrolytic capacitors is VERY reduced. Use tantalum slugs 
>>> wherever you can.

>> Better still, use SOLID Aluminium electrolytics (not the normal wet 
>> electrolytic type) . All of the advantages of tantalum and none of 
>> the disadvantages.

> I'm not familiar with those, Russell. Got links?

As ever, Google is our friend. here's a few.
Vishay multi reference page is excellent.

Philips do a good range of Solid Aluminium caps that are well priced 
and specd relative to Tantalum.

Excellent Vishay page with many technical papers on Solid 
Aluminium/aluminum capacitors (also tantalum)

        http://www.vishay.com/capacitors/volt-10-below/related

Vishay (from above page) EXCELLENT 2 page Solid Aluminium reliability 
paper
Comparison with std aluminium electrolytics.
eg lifetimes at 105C/85C/65C are  2000/2000, 20,000/8,000, 
200,000/32,000 hours

        http://www.vishay.com/docs/90017/reliabil.pdf

Vishay: Precautions using SA because they are so good ! :-)

        http://www.vishay.com/docs/90018/precaut.pdf


Good page on basic capacitor construction and principles.
Explains how a solid tantalum is made and why it is so good.
(Doesn't explain why it is also so bad).

        http://www.ami.ac.uk/courses/topics/0136_ec/


Kemet on why they are doing solid Al (1999)
Note how they introduce themselves :-)

    http://www.kemet.com/kemet/web/homepage/kechome.nsf/vabypagename/aluminum

Kemet of course do both. They note that tantalum are superior 
volumetrically. I note that Solid Al is normally very acceptable 
unless you are utterly pushing the edge of packing.

        http://www.arrowasia.com/en/arrowtimes/focus_on_01.htm


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