The impedance should be R + jwL + 1/(jwC)


You sure?, how do the j parts cancel at resonance if they are both added?

Don Pearce wrote:

On 14 Oct 2003 11:38:29 -0700, (Diego Stutzer)
wrote:

Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp.

-j/wc= 1/jwc

On Tue, 14 Oct 2003 19:56:43 +0100, Don Pearce, said...
On 14 Oct 2003 11:38:29 -0700, (Diego Stutzer)
wrote:

Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp. the resonance frequency (where Zin=R) is
1/sqrt(L*C).
At resonance frequency, the Impedance should be real and therefore in
my hummel opinion Voltage and Current schould be in phase.

The funny thing is, when i build up such a network in Schematics
(Cadence PSD 14.1/Orcad 9.2) and simulate it with the PSpice A/D
Simulator, the current is displaced (relative to the voltage) about
lambda/4 - obviously not in phase!?

Can anyone tell my where I made a mistake?
Or why this Problem is showing up?
Thanks to anyone reading this and especially to those who post
answers.
D. Stutzer

The impedance should be R + jwL + 1/(jwC)

d

_____________________________

http://www.pearce.uk.com

now that were all done playing with j...

Z = sqrt[R^2 + (jwL)^2 - (1/jwC)^2] = sqrt[R^2 + (jwL)^2 + (j/wC)^2]

this is scary ****.

mike

On Tue, 14 Oct 2003 19:56:43 +0100, Don Pearce, said...
On 14 Oct 2003 11:38:29 -0700, (Diego Stutzer)
wrote:

Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp. the resonance frequency (where Zin=R) is
1/sqrt(L*C).
At resonance frequency, the Impedance should be real and therefore in
my hummel opinion Voltage and Current schould be in phase.

The funny thing is, when i build up such a network in Schematics
(Cadence PSD 14.1/Orcad 9.2) and simulate it with the PSpice A/D
Simulator, the current is displaced (relative to the voltage) about
lambda/4 - obviously not in phase!?

Can anyone tell my where I made a mistake?
Or why this Problem is showing up?
Thanks to anyone reading this and especially to those who post
answers.
D. Stutzer

The impedance should be R + jwL + 1/(jwC)

d

_____________________________

http://www.pearce.uk.com

now that were all done playing with j...

Z = sqrt[R^2 + (jwL)^2 - (1/jwC)^2] = sqrt[R^2 + (jwL)^2 + (j/wC)^2]

this is scary ****.

mike

On 14 Oct 2003 11:38:29 -0700, (Diego Stutzer)
wrote:

Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp. the resonance frequency (where Zin=R) is
1/sqrt(L*C).
At resonance frequency, the Impedance should be real and therefore in
my hummel opinion Voltage and Current schould be in phase.

The funny thing is, when i build up such a network in Schematics
(Cadence PSD 14.1/Orcad 9.2) and simulate it with the PSpice A/D
Simulator, the current is displaced (relative to the voltage) about
lambda/4 - obviously not in phase!?

Can anyone tell my where I made a mistake?

---

1
f = -------------
2pi(sqrt(LC))


--
John Fields

John Fields schrieb in im Newsbeitrag:
...
On 14 Oct 2003 11:38:29 -0700, (Diego Stutzer)
wrote:

Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp. the resonance frequency (where Zin=R) is
1/sqrt(L*C).
At resonance frequency, the Impedance should be real and therefore in
my hummel opinion Voltage and Current schould be in phase.

The funny thing is, when i build up such a network in Schematics
(Cadence PSD 14.1/Orcad 9.2) and simulate it with the PSpice A/D
Simulator, the current is displaced (relative to the voltage) about
lambda/4 - obviously not in phase!?

Can anyone tell my where I made a mistake?

---

1
f = -------------
2pi(sqrt(LC))


--
John Fields

WOW!! Thank you soo much. The world is sound and the laws of physics apply
again. I just confused w (omega) and f.
Best Regards
D. Stutzer

John Fields schrieb in im Newsbeitrag:
...
On 14 Oct 2003 11:38:29 -0700, (Diego Stutzer)
wrote:

Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp. the resonance frequency (where Zin=R) is
1/sqrt(L*C).
At resonance frequency, the Impedance should be real and therefore in
my hummel opinion Voltage and Current schould be in phase.

The funny thing is, when i build up such a network in Schematics
(Cadence PSD 14.1/Orcad 9.2) and simulate it with the PSpice A/D
Simulator, the current is displaced (relative to the voltage) about
lambda/4 - obviously not in phase!?

Can anyone tell my where I made a mistake?

---

1
f = -------------
2pi(sqrt(LC))


--
John Fields

WOW!! Thank you soo much. The world is sound and the laws of physics apply
again. I just confused w (omega) and f.
Best Regards
D. Stutzer

On 14 Oct 2003 11:38:29 -0700, (Diego Stutzer)
wrote:

Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp. the resonance frequency (where Zin=R) is
1/sqrt(L*C).
At resonance frequency, the Impedance should be real and therefore in
my hummel opinion Voltage and Current schould be in phase.

The funny thing is, when i build up such a network in Schematics
(Cadence PSD 14.1/Orcad 9.2) and simulate it with the PSpice A/D
Simulator, the current is displaced (relative to the voltage) about
lambda/4 - obviously not in phase!?

Can anyone tell my where I made a mistake?
Or why this Problem is showing up?
Thanks to anyone reading this and especially to those who post
answers.
D. Stutzer

The impedance should be R + jwL + 1/(jwC)

d

_____________________________

http://www.pearce.uk.com

On 14 Oct 2003 11:38:29 -0700, (Diego Stutzer)
wrote:

Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp. the resonance frequency (where Zin=R) is
1/sqrt(L*C).
At resonance frequency, the Impedance should be real and therefore in
my hummel opinion Voltage and Current schould be in phase.

The funny thing is, when i build up such a network in Schematics
(Cadence PSD 14.1/Orcad 9.2) and simulate it with the PSpice A/D
Simulator, the current is displaced (relative to the voltage) about
lambda/4 - obviously not in phase!?

Can anyone tell my where I made a mistake?

---

1
f = -------------
2pi(sqrt(LC))


--
John Fields

Which voltage and which current? Clearly the voltage across the
capacitor will always be pi/2 relative to the current in that
capacitor, and the same (but opposite sign) for an inductor. Also,
are you doing an AC or a transient analysis? If transient, are the
transients settled, are you really on the resonance frequency, and are
you simulating with sufficient time resolution? Oh, and I'm not quite
sure what you mean by "lambda/4" phase shift. Is that degrees or
radians, and what's lambda?

Cheers,
Tom

(Diego Stutzer) wrote in message . com...
Hi,
Well, I'm really confused.
I simulate a simple serial R-C-L-Network (all in series).

As far as I know the total (input-)Impedance of the network is:
Z = R + jwL - j/(wC) resp. the resonance frequency (where Zin=R) is
1/sqrt(L*C).
At resonance frequency, the Impedance should be real and therefore in
my hummel opinion Voltage and Current schould be in phase.

The funny thing is, when i build up such a network in Schematics
(Cadence PSD 14.1/Orcad 9.2) and simulate it with the PSpice A/D
Simulator, the current is displaced (relative to the voltage) about
lambda/4 - obviously not in phase!?

Can anyone tell my where I made a mistake?
Or why this Problem is showing up?
Thanks to anyone reading this and especially to those who post
answers.
D. Stutzer