>So the scope's ground is hooked into 120V.  I'm fine with that, I know it
>and don't touch the scope.  Along comes my boss, Mr. Miserly "Fingerpoken
>und fiddlefarten" Pinchpenny, and sets his elbow squarely on the case of the
>scope and his other hand on a nice grounded equipment casing.  KaZAAP!

Use that isolation transformer to power the device under test, not the scope.


>circuits like the Analog Devices AD524.  I can imagine a nice high impedance
>circuit with a differential input that can float from real earth ground, but
>I can't see how  it can really isolate.  It can only handle 36 volts on an
>input pin.

So use something that can.  Burr Brown has an entire chapter of their
databook devoted to isolation products.  Optical, capacitive, digital
(ADC-DAC), and transformer coupled.  ISO100 looks good, if you can live
with the bandwidth (60 kHz).  Some of their devices even have an isolated
power supply.


>Anybody got any better ideas?

I know that there are some complete solutions in the Tektronix catalog, but
they're not likely to be cheap enough.


newell