From: wout@dutentb.et.tudelft.nl (Wout Serdijn)
Subject: Re: how can 0.022 uF be different from two 0.047 in series?!
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Organization: Delft University of Technology, Dept. of Electrical Engineering
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In <1993Apr19.185326.9830@Princeton.EDU> mg@cs.princeton.edu (Michael Golan) writes:

>I was looking at the amps diagram for Sony 1090/2090 receivers, and I
>was amazed to find a difference between the US and Canadian model
>on the capacitor(s) that hangs off the output to the speakers:

>                         ------\/\/\----- to speaker (identical both models
>from amp ---------------|
>(idnetical both models) >
>                        <  10 
>                        >
>                        |
>                       -----                        
>                      |     |                        
>        0.022        ---   ---        Canadian model only!
>     US model        ---   --- 0.047 
>     and world-wide   |     |
>     model only.      |    ---        Candian model only!
>                      |    ---  0.047
>                      |     |
>                       ----------- gound

>The board itself is also identical, with room for all three caps. The
>US/Can versions is clearly indicated in both places.

>How does that make sense? 0.047/2 is 0.0235, essentially 0.022 for caps
>(there are just standard caps, no special W/type/precision). 

>Please explain this
> Michael Golan
> mg@cs.princeton.edu

The only explanation I can think of is that two capacitors in series
can handle twice the output voltage. Sometimes two elco's in antiseries
(you know, positive sides facing eachother) are used to obtain a large
capacitor that can handle positive and negative voltages as well.

So there probably is no design-philosophical reason, but a production-cost
one.

Best 73's

Wouter
