agree in some
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I think the "infinite" crowd have themselves thoroughly confused by the differences in meaning between _impedance_ and _Thevenin_equivalence_.
Heaven help us when they discover Norton ;-)
...Jim Thompson
I read in sci.electronics.design that Rich Grise wrote (in ) about 'Input Impedance of SIMPLE Circuit', on Thu, 28 Apr 2005:
You don't need to be too modest. It's a 'tech' question, which is why I moaned about the introduction of Laplace and other exotica. The thread was lengthened by my assumption that 'Ratch' was a perverse tech rather than the (newly enlightened) student he now appears to be.
Reggie's Theorem -
To calculate the input impedance of any network simply replace internal current and voltage sources with their own internal impedances and carry on as normal.
Can't imagine what all the reams of fuss from the old wives is all about.
It's not Vin/Iin (I suspect you've misunderstood your prof). It's (delta Vin)/(delta Iin). Put a 1Mohm load on the input node and measure the
*change* in voltage divided by the *change* in current. Now make that resistor infinite (limit).Have something to add? Share your thoughts — no account required.
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