What is the cut off frequency of this LC and RC combination?

Status
Not open for further replies.
gauthamtechie said:
Anyway I will leave this and concentrate on designing it from scratch. I know I need a 3 pole high pass filter. I will choose a cut off frequency. Does anyone have an idea as to in which phase will Matlab be of use in the design process?
Click to expand...

gauthamtechie,
what you did up to now was to ANALYZE a filter circuit with given values (using Wolfram-alpha service).
In contrast, your above cited question concerns the reciprocal process - that is: DESIGN of a filter. That is a complete different approach.
What exactly is your question regarding DESIGN?
 
Yes I wasn't clear enough. Earlier,before all the posts, I thought Analysis and design were nearly complementary, but now I understand that a lot of factors need to be taken care of in design of a similar filter for another cut off.
 
 

Are you saying you want a transfer function involving the old input (which was V1) plus a new Vnew at the same time? If so, this complicates things somewhat.

The best thing might be to use a linear solver instead of inverting matrices. This technique could also be used to get the transfer function of your original problem like this. The original Y matrix is changed by removing the first row and column. This is equivalent to grounding what was the V1 node. Let's use Vin to represent the old input voltage. We inject a current into the Vx node equal to the voltage Vin divided by the impedance of C1; that current will be Vin/(1/(s C1)), or Vin*s*c1. If we do this, we get the same transfer function as before. The desired result is the (2,1) element of the result vector; I've added some red to help identify it.



Now, to have both inputs at the same time we add another current to the injected current. This current will be a current equal to Vnew divided by the impedance of L1; this will be Vnew/(s L1). Then we get this result:

 

Attachments

  • Show1.png
    11.7 KB · Views: 248
  • Show2.png
    16.8 KB · Views: 224
Status
Not open for further replies.

Similar threads

  • Question
What is the waveform and frequency of the lcr t4 device when testing the capacitor?
Replies
7
Views
639
danadak
Y
  • Question
What is this?
Replies
4
Views
777
Tony Stewart
  • Question
What is the maximum temperature of a lithium battery when overloaded?
Replies
4
Views
646
rjenkinsgb
D
What value is this melf faceless diode?
Replies
8
Views
987
dalbo
D
  • Question
What is floating ground , and why it needs insulation ?
Replies
3
Views
899
crutschow
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…