Simulation of twin t bandpass filter with potentialmeter in pspice!!

Thread Starter

jin8820

Joined Dec 8, 2010
3
Hi all,

I am trying to simulate my twin t bandpass filter with adjustable Q and constant gain but i am facing problem on it!!

i am using PSPICE schematic version 9.1.
i have included a potentialmeter on my circuit(as attached) on it. when i simulating it, error occur at the potentialmeter node, it showed " Less than 2 connections at node $N_0011".

below is the output file result:
**** INCLUDING "twin t bandpass.als" ****
* Schematics Aliases *

.ALIASES
E_U3 U3(OUT=$N_0003 +=$N_0001 -=$N_0002 )
E_U2 U2(OUT=$N_0005 +=$N_0004 -=$N_0005 )
R_R1 R1(1=$N_0007 2=$N_0006 )
R_R2 R2(1=$N_0006 2=$N_0008 )
R_R3 R3(1=$N_0009 2=$N_0005 )
C_C1 C1(1=$N_0007 2=$N_0009 )
C_C2 C2(1=$N_0009 2=$N_0008 )
V_V1 V1(+=$N_0007 -=0 )
R_R5 R5(1=$N_0002 2=$N_0003 )
R_R6 R6(1=$N_0007 2=$N_0001 )
R_R7 R7(1=$N_0001 2=0 )
C_C3 C3(1=$N_0005 2=$N_0006 )
R_R4 R4(1=$N_0010 2=$N_0002 )
E_U1 U1(OUT=$N_0010 +=$N_0008 -=$N_0011 )
RT_R8 R8(1=0 t=$N_0004 )
RB_R8 R8(t=$N_0004 2=$N_0011 )

Can anyone give me some advice on my problem?? appreciate it alot...

thanks thanks..
View attachment twin t bandpass.sch
 

Thread Starter

jin8820

Joined Dec 8, 2010
3
Hi all,

seem like i got my solution for my above problem, i make my floating node (potentialmeter) connect to the above wire. (as shown in pic).twin t.jpg

my purpose to design this filter is to get a constant gain but high Q factor bandpass filter. My center frequency is 225Hz. i need a sharp peak for my filter.
Can anyone give me some suggestion how and which parameter to adjust to make the filter has high Q (Q=20)?? i have attached as well my graph..
graph.jpg

By theory i studied, increasing the C3 value will increase the Q value, but since i tried on it, i still failed to get a high Q filter.

hope to see ur reply...thanks a lot!!
 
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