Quote:
Originally Posted by vts1134
Progress! I've got output with the correct polarity using that circuit. I'll have to do some tweaking, but it's a victory for now. One question, is there a way to adjust gain in that circuit?
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Well to tell you the truth, I built a number of projects back in the day (late 50s to early 60s) using the common emitter configuration with no resistor in the emitter-to-ground leg. They worked fine with no nonlinearity problems etc. But these were all done with germanium transistors. Apparently that does not transfer well to later practice with silicon transistors. So I was 'waay behind the curve and gave crappy advice and should be duly reprimanded.
So by all means sub some resistances in the emitter leg per the more experienced advice given.
(In the early days of transistors the "triode" analogy was indeed used as a visualization aid for newcomers. For the purpose at hand, it disregarded the input-impedance disparity. Then when FETs finally came along, the input impedance truly mimicked a vacuum triode.)