circuit equations for Pi & T networks
 

I have not seen any equations for a Pi network where you can enter the
full complex number which would include the series resistance .

I know someone must have done it but it isn't in any of the
ref-material

I have run across.

I did work out an equation some years back using APL2 which handles
complex

numbers or complex arrays. I solved the network looking into both ends
getting two equations.
rearrange both solving for the tuning cap. Then set up both equations
making

one equal the other. Then arrange all those terms (about 15 on each
side)

and solve for the loading cap. This will be a a quadratic equation.

Use the quadratic root (-B +/- squareroot (B*2 -4xAxC)) /2xA.

Now plug the values into the computer for load , inductor and Zin.

it should spit out the value of the loading cap.


It is a nasty process but someone has to do it.

I found out that if the inductor is too large negative restiance
appears in the

output value for the loading cap. Also if all goes well the answer to
the square root will be all resistive with no reactance.

Id post this however the terminal wont handle the APL characters.


Lots of luck

Art Young

AC0F

Hi,

Possibly have a look at this site -

http://www.sss-mag.com/netcalc.html


73 de Joe, G3LLV

On 2 Feb 2004 10:04:45 -0800, (Art Young)
wrote:

|I have not seen any equations for a Pi network where you can enter the
|full complex number which would include the series resistance .

The series resistance of what?

|
|I know someone must have done it but it isn't in any of the
|ref-material
|
|I have run across.
|
|I did work out an equation some years back using APL2 which handles
|complex
|
|numbers or complex arrays. I solved the network looking into both ends
|getting two equations.
|rearrange both solving for the tuning cap. Then set up both equations
|making
|
|one equal the other. Then arrange all those terms (about 15 on each
|side)
|
|and solve for the loading cap. This will be a a quadratic equation.
|
|Use the quadratic root (-B +/- squareroot (B*2 -4xAxC)) /2xA.
|
|Now plug the values into the computer for load , inductor and Zin.
|
|it should spit out the value of the loading cap.
|
|
|It is a nasty process but someone has to do it.
|
|I found out that if the inductor is too large negative restiance
|appears in the
|
|output value for the loading cap. Also if all goes well the answer to
|the square root will be all resistive with no reactance.
|
|Id post this however the terminal wont handle the APL characters.
|
|
|Lots of luck
|
|Art Young
|
|AC0F

Wes Stewart wrote in message . ..
On 2 Feb 2004 10:04:45 -0800, (Art Young)
wrote:

|I have not seen any equations for a Pi network where you can enter the
|full complex number which would include the series resistance .

The series resistance of what?


The series resistance of the inductor along with its reactance.

in that each entry is a full complex number one could enter any series

resistance associated with it say a tuning cap.

THIS MESSAGE WAS MENT TO HAVE BEEN ADDED TO ONE ON 01.19.04 BY PatW.

I GUESS I FAT FINGERED THE KEYBOARD AND MESSED IT UP.

AC0F