> If you are cost-sensitive, why not use an instrumentation opamp, some can
> sense diff voltages with 200V+ common mode. The supply (+- 15 v or so) can
> probably be taken from the amp. Must be cheaper, smaller etc than xformer.

We've been thru this already.  Such a setup would require 106dB common mode
rejection to get 1% common mode noise.


********************************************************************
Olin Lathrop, embedded systems consultant in Littleton Massachusetts
(978) 742-9014, olin@embedinc.com, http://www.embedinc.com

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