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

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

Don Pearce wrote:
The impedance should be R + jwL + 1/(jwC)


1/j = j/j*j = j/-1 = -j

-j/wC = 1/jwC

--
Pawel Stobinski
Republic of Poland

On Tue, 14 Oct 2003 21:30:18 +0200, "Pawel Stobinski"
wrote:

Don Pearce wrote:
The impedance should be R + jwL + 1/(jwC)


1/j = j/j*j = j/-1 = -j

-j/wC = 1/jwC

Quite right - the unusual format fooled me.

d

_____________________________

http://www.pearce.uk.com

On Tue, 14 Oct 2003 21:30:18 +0200, "Pawel Stobinski"
wrote:

Don Pearce wrote:
The impedance should be R + jwL + 1/(jwC)


1/j = j/j*j = j/-1 = -j

-j/wC = 1/jwC

Quite right - the unusual format fooled me.

d

_____________________________

http://www.pearce.uk.com

Don Pearce wrote:
The impedance should be R + jwL + 1/(jwC)


1/j = j/j*j = j/-1 = -j

-j/wC = 1/jwC

--
Pawel Stobinski
Republic of Poland

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


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

R + jwL + 1/(jwC)
= R + jwL -j/(wC)
so at resonance wL=1/(wC)
ie w=1/sqrt(LC)

Chris

"Michael" wrote in message
om...
The impedance should be R + jwL + 1/(jwC)


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

R + jwL + 1/(jwC)
= R + jwL -j/(wC)
so at resonance wL=1/(wC)
ie w=1/sqrt(LC)

Chris

"Michael" wrote in message
om...
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