I notice I did not run spell check on my previous! It is a rainy day here;
so, let me add something else that may not be obvious to some:

In general, the addition of negative feedback to change the output impedance
does not change the dynamic range.

Consider the following. An ideal DC op amp operating from a 10V supply with
0 output impedance, and infinite gain.

1. Put a 1K resistor in series with the output.

2. You now have an op amp with 1K output impedance.

3. Connect the inverting input of the op amp to the other end of the 1K
resistor. Call that the output terminal. and connect a load resistor Rl from
there to ground. ( The gain from the non inverting input to Rl =1 in the
linear range)

4. Because of the infinite feedback, the output impedance is now 0 again,
but all of the load current still flows through the 1K series resistor. It
will not, for instance, deliver 5V into a 910 Ohm resistor because the
amplifier will have saturated before that point. For a given RL, the maximum
voltage you can get out is (10 x Rl)/(1000 + Rl) with or without feedback.

Tam/WB2TT
"Cecil Moore" wrote in message
...
Tarmo Tammaru wrote:
Anybody for going down to the local power company and conjugate matching
all
thouse pesky AC generators?

That's why Edison thought AC would never catch on. I'm looking
for a ham amp with the internal impedance of a 100 MW AC
generator. :-)
--
73, Cecil http://www.qsl.net/w5dxp



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