[Hallicrafters] capacitor question for cap whizbangs

[Bill]

Well, technology.  You can now buy 1F capacitors, I do mean 1 F. Just
 check out digi-key. They are the size of a large button and are used
instead
 of battery backup.

Alot of the hi-voltage caps now are used in switching power supplies.
To ensure switching power supplies do not mess with the Power Factor too
much,
 they switch up to 300V first then do bring the voltage to where they
need them.
 (hopefully I got the right)

As to technology, I would guess that computer controlled manufacturing
techniques,
better chemistry have helped.

-----Original Message-----
From: hallicrafters-bounces at mailman.qth.net
[mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of
Nash4447 at cs.com
Sent: Saturday, September 08, 2007 11:55 PM
To: hallicrafters at mailman.qth.net
Subject: [Hallicrafters] capacitor question for cap whizbangs



I have a piece of electronic gear built about 1980 that uses a pair of 
6.8MF  100V block type capacitors. The caps are almost the size of a
pack of 
cigs.

I recently purchased a pair of replacements marked with the same
capacity and 
voltage ratings yet the things are just slightly bigger than a pencil 
erasure. 

What happened over the intervening 25 years that allows today's
capacitor 
makers to achieve the same capacitances & voltage ratings in such tiny
packages? 
Its really hard for me to believe that one will replace the other
considering 
the dramatic size differences. 

Comments?

Glenn    
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