Ohm's law, Impedance

Discussion in 'General Electronics Chat' started by joejoenikk, Sep 21, 2012.

  1. joejoenikk

    Thread Starter New Member

    Nov 23, 2011
    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.