[sdiy] electrolytic coupling capacitors

[blitz]

This is the same question I am having.  Should you face the positive 
side towards the output of the opamp in coupling the output?  If it's 
in series (for an AC coupling capacitor) wouldn't you generally see 
the same voltage on both sides of the cap?  Except when it's blocking 
DC, then you would see a higher voltage before the DC blocking and a 
lower voltage (ideally 0) after the cap.

-Joe

At 11:10 PM +0000 10/31/04, Peter Blackett wrote:
>Dear List ,
>just a quick question with regard to coupling caps.
>what do you do when the voltage on either side of the caps is 
>roughly the same ?
>is it beter to arrange for there to be a small amount of offset on 
>the output on the op amp side of the coupling cap, or not. ?
>it is well worth having coupling caps on the inputs of amps/mixers.
>as you never know what circuits might put dc on the input !
>regards Peter
>
>     Theo wrote:
>>Look at the level of the "internal" reference voltage and assume the
>>"outside" reference voltage to be 0V.
>>Now mount the caps so that they are polarized correctly based on the
>>reference voltages.
>>BTW Usually this means the positive side looks at the circuit.
>>
>>HTH
>>Theo
>>