these two terms seem to be at the core of efficient electronic design but for some reason are generally bypassed by the hobbyist electrician, myself included.
i would like to start a conversation to bring these concepts into simple, usable terms that can be explained to even an entry level hobbyist so that they will understand, see the importance and be able to implement these concepts in their builds (again...myself included!).

are these terms related?

how do we apply each term without getting bogged down in theory-crating?

why is the number 42 so important anyways?

There's some contradiction in terms here.

To start with, there's no DC reactance per se, what you get the very moment you close the circuit on say a battery powering an inductance, let's say a coil, is a very low current in the circuit to start with, only to see an increase of the current to the point of having it reaching a maximum current which is only limited by the coil's Ohmic resistance, together with what internal resistance there may be in the battery and also what little resistance there may be in the cables, the switch closing the circuit, terminals etc.

Reactance "only" plays a role when the current changes, such as with an AC current which has a certain frequency.
In this case the, I.E when powering a coil using AC current as opposed to DC, the coil impedance, which is made out of both it's resistance and it's inductive reactance, becomes the main current limiter and as the inductive reactance changes with frequency (the higher the frequency the higher the inductive reactance), the overall impedance also changes accordingly.

Resonance can be seen as an reactance match between an inductive and an capacitive reactance, which occurs at a specific frequency, I.E when the inductive reactance is equal to the capacitive reactance, then the circuit's resonance condition is reached and depending on how the reactances are connected to the power source, which basically is either in series or in parallel, either the voltage or the current will maximize in/through/across the circuit at hand and changing the frequency from the power source will of course take away the very resonance condition.

This is a very short and basic description, but I couldn't really describe it any shorter than this.

Some references, http://en.wikipedia.org/wiki/Electrical_reactance
http://en.wikipedia.org/wiki/LC_circuit

no worries thats exactly what im talking about...trying to simplify the terms and concepts, draw easy to follow lines of relationship, etc. i think you have done that quite well  :)

Thanks, it's not the easiest concepts to grasp from the get go, takes some experimenting, burning coils and transistors, blowing fuses, etc etc, before you start to see how it all relates to eachother ;-)

Quote from jeremy gwilt on March 25th, 2015, 08:02 AM

are these terms related?

how do we apply each term without getting bogged down in theory-crating?

Good toughts..

..

We know that  AC is very similar to  Pulsed DC...

Reactance is created with changing field value.
Is there a change in the field value? if there is then there is Reactance.

Resonance..    Acording to wiki... "is ability to store vibrational energy"....

So at resonance in a "Tank Circuit" the exchange of charge among the inductance and capacitance is at its most efficient rate.
yet the" vibrational energy" is disipated along a curve.

Reactance is like a Train.. hard to start.. hard to stop.. once going doesnt like change.

Resonance is like when the train is maintaned at a steady pace.... At this pace the  efficiency will be at its greatest. less energy  than starting the traiin and less energy  than stoping it.