are caps and coils linear circuit elements?

L

Lax

Jan 1, 1970
0
iv curves of caps and coils are not linear, so are they nonlinear or
linear circuit elements?

What is the definition of a linear circuit?
 
T

Tim Wescott

Jan 1, 1970
0
iv curves of caps and coils are not linear, so are they nonlinear or
linear circuit elements?

What is the definition of a linear circuit?

The idealized models of capacitors and inductors show them as being
linear, because they obey superposition.

Real world capacitors and inductors can show nonlinear behavior if you
push them hard enough -- particularly electrolytic caps and iron-core
inductors, but anything will spark over if you make the voltage high
enough, or overheat if you make the current high enough.

A linear system is one that obeys superposition; for a system h that
takes signal x to generate signal y, y = h(x). If you can show that

h(x1 + x2) = h(x1) + h(x2)

for _any_ two signals x1 and x2 then the system obeys superposition* and
it is linear.

* Saying h(a1*x1 + a2*x2) = a1*h(x1) + a2*h(x2) is sufficient, but not
necessary -- with enough analysis you can show that this relationship
flows from the prior definition of superposition that I showed.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html
 
J

John Larkin

Jan 1, 1970
0
iv curves of caps and coils are not linear, so are they nonlinear or
linear circuit elements?

What is the definition of a linear circuit?

An element is linear if applying N times the input (say, voltage)
always results in exactly N times some output (like current maybe). We
consider ideal resistors, capacitors, and inductors to be linear.

A circuit is linear if applying N times an input produces N times the
output. Note that N could be any number, positive or negative. So if
N=-1, that implies that if you invert the input, the output exactly
inverts in response.

Unlike resistors, the IV curves of Ls and Cs involve time... the
curves are sort of three dimensional. But that doesn't make them
nonlinear.

John
 
J

John Larkin

Jan 1, 1970
0
An element is linear if applying N times the input (say, voltage)
always results in exactly N times some output (like current maybe). We
consider ideal resistors, capacitors, and inductors to be linear.

A circuit is linear if applying N times an input produces N times the
output. Note that N could be any number, positive or negative. So if
N=-1, that implies that if you invert the input, the output exactly
inverts in response.

Unlike resistors, the IV curves of Ls and Cs involve time... the
curves are sort of three dimensional. But that doesn't make them
nonlinear.

John


Which implies that Ls and Cs are linear in time, too.

John
 
M

Mark Zenier

Jan 1, 1970
0
** Fuckwit Groper alert !!
** Jesus H. Christ you are a dumb turd.
http://en.wikipedia.org/wiki/Linear_circuit
....... Phil

Charters and description lines.

sci.electronics.basics Elementary questions about electronics.

"A forum for discussion of electronics where there is no such
thing as a stupid question. Beginners questions. Discussion of
electronics education. Requests for other sources of information."

Mark Zenier [email protected]
Googleproofaddress(account:mzenier provider:eskimo domain:com)
 
J

John Larkin

Jan 1, 1970
0
Charters and description lines.

sci.electronics.basics Elementary questions about electronics.

"A forum for discussion of electronics where there is no such
thing as a stupid question. Beginners questions. Discussion of
electronics education. Requests for other sources of information."

Mark Zenier [email protected]
Googleproofaddress(account:mzenier provider:eskimo domain:com)

The Basics group is where Phil has to go to find people he thinks he's
smarter than, so he can abuse them for being dumb.

Is that smart?

John
 
R

Rich Grise

Jan 1, 1970
0
Charters and description lines.

sci.electronics.basics Elementary questions about electronics.

"A forum for discussion of electronics where there is no such
thing as a stupid question. Beginners questions. Discussion of
electronics education. Requests for other sources of information."

Most of us learn to ignore Phil early on.

Cheers!
Rich
 
P

Phil Allison

Jan 1, 1970
0
"Mark Zenier"

** Wot a fucking PITA wanker.

Phil Allison


Charters and description lines.

sci.electronics.basics Elementary questions about electronics.

"A forum for discussion of electronics where there is no such
thing as a stupid question. Beginners questions. Discussion of
electronics education. Requests for other sources of information."


** The OP is dumb turd for NOT making any effort to find his answer on
Google and instead preferring to WASTE the time of others here.

And YOU are an even BIGGER turd for encouraging shits like him to do
that.



........ Phil
 
J

John Larkin

Jan 1, 1970
0
"Mark Zenier"

** Wot a fucking PITA wanker.




** The OP is dumb turd for NOT making any effort to find his answer on
Google and instead preferring to WASTE the time of others here.

Maybe he tried. Maybe he found a heap of equations that he didn't
understand. Maybe he wanted to talk about it.
And YOU are an even BIGGER turd for encouraging shits like him to do
that.

What's wrong with basic questions on a "basics" group, and why do you
lurk, always ready to pounce? I suppose it makes you feel potent or
smart or something else you aren't in real life.

The idea of linearity on the third axis, time, is actually sort of
interesting.


John
 
P

Phil Allison

Jan 1, 1970
0
"John Larkin = dribbling autistic DOLT "
Maybe he tried.


** Maybe the moon is made of green cheese ????




....... Phil
 
J

Jamie

Jan 1, 1970
0
Phil said:
"John Larkin = dribbling autistic DOLT "





** Maybe the moon is made of green cheese ????




...... Phil
You might be onto something there Phil!
 
S

stan

Jan 1, 1970
0
Phil said:
"John Larkin = dribbling autistic DOLT "



** Maybe the moon is made of green cheese ????
You remind me of a guy I knew in the military. He appeared totally
worthless. He spent 6 months going to dental appointments every day so
he could get off early to work on his boat. In the meantime others had
to do his work. That wasn't actually so bad because when he did his own
work we usually ended up redoing it. Then one day someone actually told
him he served no purpose. He thought for a minute and the said
"everyone needs a bad example too". You seem very similar. I've never
seen anyone as unpleasant for no reason. You stand as a frequent
reminder to not hit send if you don't have anything constructive to say.
Finally, I have to admit that as far as bad examples go, you're the
tops!

I fully realize that nothing I could say or do would fix you. I'm not
that powerful. My intention here was to write this on the record for
myself as a permanent reminder to watch what I write and how I treat
people. I have been accused of being challenged in the area of "tact" so
I need reminders and you do a fine job.

For electronic content, I think the idea John brought up about three
dimensional representations is strange and deserves a little more
thought.
 
M

Mark Zenier

Jan 1, 1970
0
....
** Wot a fucking PITA wanker.

That's fucking PITA newsgroup creator/Proponent/charter author to you,
you pathetic misanthrope.

....
** The OP is dumb turd for NOT making any effort to find his answer on
Google and instead preferring to WASTE the time of others here.

And YOU are an even BIGGER turd for encouraging shits like him to do
that.

This is a discussion forum. IT'S PURPOSE IS "WASTING TIME".

Mark Zenier [email protected]
Googleproofaddress(account:mzenier provider:eskimo domain:com)
 
L

Lax

Jan 1, 1970
0
Maybe he tried. Maybe he found a heap of equations that he didn't
understand. Maybe he wanted to talk about it.

This is true. I actually checked Wikipedia also, but didn't
understand the whole sinusoidal response definition. In my head I was
using a cap's (or coil's) iv characeristic and a randon input into
this circuit:

Vin o------/\/\/\/\-----o-----| |-------GND (output across cap..
middle node).

I was thinking to myself, if I place a random voltage waveform at Vin,
I certaintly won't be guranteed an ouput that is linear with respect
to it. For example, a triangle wave input doesn't result in a
triangle wave output.

So this is why I was thinking to myself: "why is this circuit linear?
Rs are linear, but if Cs were also linear then the response to any
input waveform should be proportional to it."

But now I get that the term "linear" is only for sine wave inputs.
 
P

Phil Allison

Jan 1, 1970
0
"Mark Zenier"
That's fucking PITA newsgroup creator/Proponent/charter author to you,


** Then you are an even BIGGER ASS than I had imagined.

This is a discussion forum. IT'S PURPOSE IS "WASTING TIME".


** What a demented load of bollocks.

Completely autistic.



........ Phil
 
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