[sdiy] bio electricity

[Czech Martin]

I have a ciruit for an isolation amplifier (3kV) that
should be good enough to isolate battery driven electrode
preamps from any other circuits.

I also remember that http:www.elv.de sells an optical
isolation amp that uses two matched devices for servo
error cancelation due to characteristic nonlinearities
etc. They claim that it is good enough for
audio and could replace transformers, whatever that may
say. optical has the advantage that very low frequencys
can be processed (of course with unknow DC bias to gnd),
this is not possible with transformers (until you use FM, chopper
or AM methods). Hey, this is also a nice idea: use two 4046
for FM modulation and demodulation, now transformers as well
as digital optical isolation stuff can be used.

Do you remember the FM audio distribution allong the 
home mains power lines?


m.c.