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Re: Ohm's Law



At 10:21 AM 11/8/99 -0500, Bob Sciamanda wrote:
dV/dI is the important quantity for evaluating the effect of small signal
voltages which oscillate about some DC bias value.

Right. That's usually the important quantity. When somebody talks about
"the resistance" of a non-ohmic device, it's usually shorthand for the
small-signal resistance.

For non-ohmic devices, the quantity V/I is usually quite unimportant. I
don't think real-world engineers would call V/I "the resistance" without
qualifiers. I'm not sure V/I has a name or even deserves a name.

Then at 04:08 PM 11/8/99 -0800, Leigh Palmer wrote:

In the olden days it was dI/dV, the transconductance,
which served this function.

I don't think a two-terminal device has a transconductance or a
trans-anything. Usually dI/dV is just called the small-signal conductance.