impedancesource
Regarding the following excerpt:
High impedance source gives you more volts and less current
Low impedance source gives you lower voltage but more current
What is meant by low impedance source and high impedance source here?
By "impedance" is it meant the output impedance? If so how is that relates to the source utilizing more power? How to comprehend this by circuit model? I came to this confusion after reading about piezoelectric amplifying techniques.
You could do something like this if you're not afraid of op amps. The microphone gets its high impedance, and if it needs higher impedance, increase R1. I have the iPod a 330 Ohm load because I seem to remember reading somewhere that's a good starting point. The output impedance is 10k, and can be increased if necessary. This circuit has a gain of 2, so if you need less, decrease R6, and if you need less than 1, switch it to an inverting configuration. Trying to sum these inputs passively is going to require a matching network.
The output impedance varies a bit with current, but only slightly, so you can use the value given in the datasheet for higher currents too. (Note that the 160 mV is a typical value, and that the value may be as high as 400 mV. Then the impedance will be 25 Ω, so it's not precise anyway.)
This graph is from the ATmega64 datasheet, and shows output voltage versus sourced current. If the output resistance would be constant we would have straight lines. They're slightly curved, but the difference in resistance is far less than the tolerance given in the datasheet.
Best Answer
I don't agree with those statements by themselvas they intend to be generically true but they're not. If a sentence was added like:
Here's an example of both:
simulate this circuit – Schematic created using CircuitLab
Here the load and source impedance are the same, that's because I want to extract the maximum amount of power from the source. Both sources will deliver 2 Watts each.
Note how the power in my load resistor is 1 Watt in both cases. In the high(er) impedance case, the voltage is 10x higher but the current is 10x lower.