Inductors vs. Capacitors

Thread Starter

hondabones

Joined Sep 29, 2009
123
Hello All!

I noticed a few similarities in the calculations. Like, inductors in series are calculated similar to resistors in series. However, caps in series are similar to resistors in parallel.

If you compare the two components (caps and inductors) they are basically inverses of each other. I am having trouble understanding the practical application and the purpose of these two components.

They have such a unique relationship there must be some reasoning behind this. We are already beginning to learn series RLC circuits. I would like to understand the inductor vs. the capacitor before we combine the two components.

Jim
 

Thread Starter

hondabones

Joined Sep 29, 2009
123
The light bulb will go off when you study "resonant circuits".
We did study resonate frequency just yesterday. There is no light bulb involve at this time so I don't understand your post at this time.

Thank you for your reply. I welcome any input. I absolutely love my decision to get into electronics.
 

MikeML

Joined Oct 2, 2009
5,444
The nugget that you obviously missed while studying resonant circuits is that capacitive reactance cancels inductive reactance.
 

Thread Starter

hondabones

Joined Sep 29, 2009
123
The nugget that you obviously missed while studying resonant circuits is that capacitive reactance cancels inductive reactance.
Your probably right. I know that when XL goes up XC goes down. Let me rephrase that. As frequency goes down XL goes up and XC goes down. At the point where XL and XC are the same is resonate frequency. Did I accurately state this?
 

alphacat

Joined Jun 6, 2009
186
Your probably right. I know that when XL goes up XC goes down. Let me rephrase that. As frequency goes down XL goes up and XC goes down. At the point where XL and XC are the same is resonate frequency. Did I accurately state this?
As frequency decreases, XL (ωL) decreases and XC (1/[ωC]) increases.
 

KL7AJ

Joined Nov 4, 2008
2,229
Here's a little algebraic gymnastics you can do, if you're up to it. In fact, I just demonstrated it to my class last night!

XL = 2*pi*fL
XC = 1/2*fC

Set 2*pi*fL= 1/2*pi*fC

Now solve for f.

This will give you the resonant frequency formula in terms of L and C.

Great exercise. :)

eric
 

Thread Starter

hondabones

Joined Sep 29, 2009
123
Here's a little algebraic gymnastics you can do, if you're up to it. In fact, I just demonstrated it to my class last night!

XL = 2*pi*fL
XC = 1/2*fC

Set 2*pi*fL= 1/2*pi*fC

Now solve for f.

This will give you the resonant frequency formula in terms of L and C.

Great exercise. :)

eric
No kidding! We just learned that last night in class too.

f = 1/2pi√(LC)
 

russ_hensel

Joined Jan 11, 2009
825
Both inductors and caps. shift the phase relationship between voltage and current. In exactly opposite directions. Becomes much clearer in the complex plane. Wait for it, it is so cool.
 

jans123

Joined Jan 30, 2010
20
Another aspect is that inductors and capicators store energy, resistors don't. Inductors can give the energy away as very nasty high voltage when circuits opens and capacitors can deliver banging currents when circuits closes.
Resistors just tries to convert the energy it gets into heat.

OUCH!
 

Thread Starter

hondabones

Joined Sep 29, 2009
123
Another aspect is that inductors and capicators store energy, resistors don't. Inductors can give the energy away as very nasty high voltage when circuits opens and capacitors can deliver banging currents when circuits closes.
Resistors just tries to convert the energy it gets into heat.

OUCH!
This basically answers my question.

You're saying that inductors effect voltage and caps effect current. Right?
 

jans123

Joined Jan 30, 2010
20
In a way... yes, but it is more complex than that. Inductors don't like changes in current and tries to keep it constant. It has to do with the magnetic fields building up and braking down. It stores energy as a magnetic fild, whilst capicators shuffles charges (electrons) and don't like changes in the voltage.
It is really the moving electrons in the inductor that creates the magnetic field and if you tries to break the current trough a inductor the collapsing magnetic field will induce voltage in the windings that tries to keep the electrons going at the same rate, whatever the sice of the beak in the circuit are, that's why a arch of current (sorry my English vocabulary is limited) flow between the contacts and damage the switches. On the other hand, the capicator stores energy as electrons and the bigger the difference is between the voltage on the capicator and the voltage source is when you connect it, the bigger the current are when the switch is turned on.

Sorry, can't give a simple answer. If I try i would probably end up in an even bigger confusion.
 
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