How Do Inductors and Capacitors Operate in AC/DC Circuits?

[pooface]

My knowledge on how inductors and capacitors operate in AC/DC is a bit shaky. My textbook and online material don't help my understanding, so I am hoping someone would be able to explain it more clearly.

In DC I know that capacitors store energy and charge up by time constants and then release their energy when used as independant sources. They gain voltage as they charge. I have firm knowledge here.

In AC, I have a few questions. I do know that there is Xc and using ohms law there is voltage dropped across the capacitor.

My question, is there energy stored in the capacitor in the same way of DC? In a FW bridge filter circuit, to smooth out the AC current the capacitor does discharge some current, hence the ripple. How does this work in AC?

My educated guess would be to convert the AC voltage to the DC equivalent and use DC properties to see how much the capacitor charges etc. This would mean that the capacitor stores energy in DC and has a separate AC voltage drop. Is this statement correct?

For inductors I have a much weaker understanding.

In DC, I don't know how inductors actually work except that they store energy in the form of an magnetic field. But I don't know how this actually works. Is it the same as capacitors where as time goes by the capacitor produces voltage opposing the DC source? Does it use time constants as well?

In AC, I know that Inductors have XL and also drop a voltage by ohms law. But how do they work in AC? What is their purpose except to bring the current/voltage out of phase and for resonance?

Thank you.

 

[Astronuc]

In DC, a capacitor is like an open circuit. The current flows until a charge builds up and a voltage across the capacitor is established.

In AC, the voltage and polarity are changing, and the potential on the capacitor would change correspondingly.


In DC, an inductor is basically a short circuit. The magnetic field develops with a time changing current, which is what happens with AC.


Both inductors and capacitors affect the relationship between voltage and current in AC.


Is one familiar with RC, RL and RLC cirucits?

See if these are useful -

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capcon.html#c1

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/indcon.html#c1

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/accircon.html#c1

 

[piercas]

I would be happy to help clarify your understanding of inductors and capacitors in AC/DC circuits.

First, let's start with capacitors in AC circuits. In AC circuits, capacitors still store energy in the form of an electric field, just like in DC circuits. However, the difference is that in AC circuits, the voltage across the capacitor is constantly changing, which causes the capacitor to charge and discharge at a much faster rate compared to in DC circuits. This is because the voltage in AC circuits is constantly changing direction, causing the capacitor to charge and discharge in both directions.

In a FW bridge filter circuit, the capacitor does discharge some current, but it also charges up again quickly due to the changing AC voltage. This results in the ripple effect that you mentioned. So, in AC circuits, capacitors still store energy, but the rate at which they charge and discharge is much faster due to the constantly changing voltage.

Moving on to inductors, in DC circuits, they store energy in the form of a magnetic field. This is achieved by passing a current through the inductor, which creates a magnetic field around it. The inductor then resists changes in current, which is why it is often used in circuits to smooth out fluctuations in current.

In AC circuits, inductors also play a role in storing energy, but their main purpose is to create a phase shift between voltage and current. This is because inductors have an inherent property called inductive reactance (XL), which causes the voltage and current to be out of phase. This can be useful in circuits such as filters and resonant circuits.

Overall, inductors and capacitors play crucial roles in both DC and AC circuits, and their properties and behaviors are a result of the changing voltages and currents in these circuits. I hope this explanation has helped clarify your understanding of these components.