[sdiy] Buffering 0V when using a pot as a voltage divider?

[Neil Johnson]

David G Dixon wrote:
> However, in all seriousness, one must admit that all of these problems with
> ground stem from creating impedance (dc or ac) on the traces and/or cables
> between the actual ground (at the PSU) and the connection point.  In
> principle, this impedance is zero, and if that were always so, then there
> would never be any problems with ground.  Isn't that right?

Yes, *in principle*.  But unless you build your circuits using cooled 
superconductors for all your grounds then they *will* have non-zero 
impedance.

Maybe you've been lucky.  So far.  But as an academic I'm sure you're 
aware of the problem of induction.

Neil
-- 
Synth DIY 2011 -- www.diy.synth.net/uk
Homepage -- www.njohnson.co.uk