On 11 Sep 2000, at 9:22, Barry King wrote:

>
>
> An EEG amp sounds interesting- is the main challenge that the common-
> mode noise is many times greater than the signal?
>
Yes

Basically picking microvolts out of volts of noise.
The return/common paths on PCB layouts are super critical. I pays
to think in terms of the copper tracks being high value resistors (like
printed carbon or something). To reject a common mode signal it
has to be common mode!!!!!
_____________________________

Lance Allen
Technical Officer
Uni of Auckland
Psych Dept
New Zealand

www.psych.auckland.ac.nz

_____________________________

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