Complementing #12's recent post:
"Ohm's law" has an interesting version of absolute truth, for those atomic scientists and mathematicians out there, don't let it bother you it really is actually a self enforcing reality.
Back when they were trying to develop Universal standards for electricity, they defined "ohms law" and it's reality; it is "true" law. The Early definitions of how to correctly design and build a volt an amp meter, first require the building or purchasing of a DC power cell, then include the addition of unform gauge wire of consistent and specific wire be used in a meter movement. The galvanic voltages and impedances inherent to the design were not observed in those definitions and are simply incorporated by the following works and carried on.(My -7 digit DC volt meter is currently using a coaxial feed, however the manufacturer of the high end instrument never thought I may not be able to find gold wires to hook up to the banana connectors.)
Personally, I enjoy setting a target impedance at the beginning of my design work and find it is much easier than wondering about the mystery of how I accomplished any specific impedance. For example, when I really don't care about distortion harmonics and oscillations, such as a LED regulator, I can set an impedance of 50 for one stage and a thousand for the next, where if it is a really expensive and damaging area, one stage will have an impedance of 50 but the next stage will have to stick with the common, well studied, value of 300.
"Ohm's law" has an interesting version of absolute truth, for those atomic scientists and mathematicians out there, don't let it bother you it really is actually a self enforcing reality.
Back when they were trying to develop Universal standards for electricity, they defined "ohms law" and it's reality; it is "true" law. The Early definitions of how to correctly design and build a volt an amp meter, first require the building or purchasing of a DC power cell, then include the addition of unform gauge wire of consistent and specific wire be used in a meter movement. The galvanic voltages and impedances inherent to the design were not observed in those definitions and are simply incorporated by the following works and carried on.(My -7 digit DC volt meter is currently using a coaxial feed, however the manufacturer of the high end instrument never thought I may not be able to find gold wires to hook up to the banana connectors.)
Personally, I enjoy setting a target impedance at the beginning of my design work and find it is much easier than wondering about the mystery of how I accomplished any specific impedance. For example, when I really don't care about distortion harmonics and oscillations, such as a LED regulator, I can set an impedance of 50 for one stage and a thousand for the next, where if it is a really expensive and damaging area, one stage will have an impedance of 50 but the next stage will have to stick with the common, well studied, value of 300.