In alternating current, we may have inductors and capacitors which make voltage and current become out of sync.
At the beginning, I was stuck because how can it be that there is first voltage and then current? Now I realized that it's not the current or the voltage itself what is going before or after the other.
It's the way the values increase and decrease what is out of sync.
Both voltage and current start simultaneously existing at the exact same time, but their values increase, decrease and are zero at different times.
That has clarified my ideas a lot, but I am struggling to visualize what is really going on in each case.
I think this can be broken down to:
- The effect of voltage being greater than current.
- The effect of voltage being lower than current.
- The effect of having whatever voltage and zero current.
- The effect of having zero voltage and whatever current.
Apart to those facts, there is also a need to deal with what happens with positive and negative values, which could be broken down to:
- The effect of having opposite voltage and current.
- The effect of having same-direction voltage and current.
Could anyone please provide some analogies or simplified views where the effect of this can be understood?
Of course analogies might not be 100% accurate or might oversimplify stuff, but it's better to have a simple understanding than none. Which means: whatever coherent insight will be highly appreciated.
For the sake of not making this a lazy question, I will explain what my intuition tells me:
The effect of voltage being greater than current:
High voltage and low current means that some force is pushing the current back. It could also be that there is only a small amount of charge available in the circuit.
The effect of voltage being lower than current:
Low voltage and high current means that there is an extra force helping the current to flow faster.
The effect of having whatever voltage and zero current:
I cannot understand this. The only way for this to happen is to have a barrier that does not allow charge carriers to cross that barrier.
The effect of having zero voltage and whatever current:
Current does not have any motivation to flow if there is no voltage. This could only happen if there is some kind of inertia.
The effect of having opposite voltage and current:
This is even crazier. Voltage pushes the charges from A to B, but they just decide to go from B to A. Something must be causing this reverse behaviour.
The effect of having same-direction voltage and current:
This seems to be very normal.
My brain explodes when I try to put all of this together.
But this is what it understands (can you please correct the wrong affirmations?):
Voltage is what is actually being created at the source (for example a magnet that goes in and out of a coil).
Current flow is the consequence of voltage (And never viceversa).
The fact that the magnet smoothly goes in and out explains the sinusoidal form of AC.
Smoothly in from -max to max, stop, smoothly out from max to -max.
In a simple circuit with a resistance, both voltage and current would go together.
If I introduce a capacitor, with the capacity of storing the charges... it "steals" the current for a while, until it just stops "stealing" (= is full). That would make the current disappear or stop at some point, but it does not apparently relate to the waves shown above.
If I introduce an inductor, with the behaviour of stopping the charges flow until a magnetic field is created... it "pushes back" the charges until they just keep going on. That would make the current and voltage sync back at some point, but it does not apparently relate to the waves shown above.
If I introduce both a capacitor and an inductor, it could be broken down to having only one of both. The one that is "bigger" wins. And its behaviour could be understood by understanding the previous ones.
This is a broad question, but I feel this is the only way I can ask, since that is the big picture and it makes no sense to break it down into many small separated questions.
Thanks for your attention.
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