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passive analogue circuit in digital representation

PostPosted: Mon Oct 15, 2018 12:22 pm
by Rocko
Hi,

I would like to experiment a bit with transferring analog circuits into digital representation. For starters, I'm focused with passive analogue modules only and filters of order 1-2-3-4.
I've read a few posts in this forum, but not sure I really found my answer...

For instance, can I transfer any given analog circuit (which makes sense and works) with passive RLC compontnets,into digital domain as an FIR/IIR filter?
Is there a tool (MATLAB/SImulink or the like) which I can "throw in" an analog circuit design and output a filter of shape:

Y[n] = a0 * x[n] + a1 * x[n-1] +... + b1 * Y[n-1] +...

Which I can then use in Flowstone ?

Re: passive analogue circuit in digital representation

PostPosted: Tue Oct 23, 2018 11:57 am
by Rocko
Hey... Anyone ?

Maybe MATLAB + Simulink can help ?

Re: passive analogue circuit in digital representation

PostPosted: Tue Oct 23, 2018 1:54 pm
by TheOm
There exist multiple methods for transforming continouus time circuits to discrete time.
See:
Impulse Invariance
Bilinear Transform
Matched Z-Transform

I also recommend this paper where another method called topology-preserving transform is introduced
https://www.native-instruments.com/fileadmin/ni_media/downloads/pdf/VAFilterDesign_2.0.0a.pdf

I think MATLAB can definitely help, for example: https://www.mathworks.com/help/signal/ref/bilinear.html

Re: passive analogue circuit in digital representation

PostPosted: Wed Nov 07, 2018 11:03 am
by Rocko
Thank you for the answer.

I think there are two stages here:
1. From an analog circuit (drawing) to H(s) [continous time transfer function]
2. From H(s) to H(z) [discrete time transfer function]

The above answer is perfect for the second part { H(s) to H(z) }.

But could you recommend me a software solution for converting an electric-analog circuit (L,C,R Kirchoff...) to H(s) ?

Re: passive analogue circuit in digital representation

PostPosted: Wed Nov 07, 2018 3:25 pm
by wlangfor@uoguelph.ca
I thank You both for Your efforts. The fact that You have found a solution for converting electrical formula's so that they can
be converted to math is very exciting. I'm also looking forward to using such a software that can convert it into something We
can use.

Re: passive analogue circuit in digital representation

PostPosted: Wed Nov 07, 2018 4:48 pm
by DigiTonix
Hi guys! I see that you are talking about simulation. I have been working on this issue for a very long time ... I tried different methods (in the course of work I accidentally created distortions with unpredictable behavior.) I was distracted ...
Roco wrote that he wanted to learn how to make passive components to begin with.
I highly recommend using NI MULTISIM. :idea:
1) It allows you to listen to the sound of any circuit ..
2) It allows you to create an IR pulse.
3) It allows you to create any equalizer, amplifier, or effects pedal.

Re: passive analogue circuit in digital representation

PostPosted: Wed Nov 07, 2018 4:49 pm
by DigiTonix

Re: passive analogue circuit in digital representation

PostPosted: Wed Nov 07, 2018 5:20 pm
by DigiTonix
I also often use Proteus 8, it is also good !!!
As for non-linear components, you can also use this!
http://www.ni.com/tutorial/12784/en/

I'm not sure that this is what you wanted, but I think to be useful to you.
I use this method, I do not know another) :oops:

Re: passive analogue circuit in digital representation

PostPosted: Wed Nov 07, 2018 6:38 pm
by wlangfor@uoguelph.ca
DigiTonix wrote:Hi guys! I see that you are talking about simulation. I have been working on this issue for a very long time ... I tried different methods (in the course of work I accidentally created distortions with unpredictable behavior.) I was distracted ...
Roco wrote that he wanted to learn how to make passive components to begin with.
I highly recommend using NI MULTISIM. :idea:
1) It allows you to listen to the sound of any circuit ..
2) It allows you to create an IR pulse.
3) It allows you to create any equalizer, amplifier, or effects pedal.


Thanks Digi, I'll look into that.

DigiTonix wrote:https://youtu.be/fF6gI4w-LuE


Very Good, Cheers.

DigiTonix wrote:I also often use Proteus 8, it is also good !!!
As for non-linear components, you can also use this!
http://www.ni.com/tutorial/12784/en/

I'm not sure that this is what you wanted, but I think to be useful to you.
I use this method, I do not know another) :oops:


Proteus, heard that somewhere.. Will look into it. :)
Thank You.

Re: passive analogue circuit in digital representation

PostPosted: Thu Nov 08, 2018 8:52 am
by Rocko
Hi,

Thanks for the answers, but I'd like to focus my question even more.

My original question is if there is an automatic tool that can SOLVE the electronic circuit ( SOLVE = derive the transform function H(s) )
I think (not sure) that Simulink, Proteus, MultiSim, etc. can SIMULATE the circuit, but can it provide the transform function ?

Simulation:
The solution (Proteus, MultiSim, etc.) can pass different signals through the 'circuit' and provide the Magnitude graph, the phase graph (BODE), Impulse response, etc.
But can it provide the transfer function in time domain or in 'S' domain (Laplace transform) ?

SOLVE = Derive the transfer function:
A (human) electronic engineer can take a circuit diagram and 'solve' it by using Kirchoff laws (KCL, KVL) to reach the transfer function in time domain representation, from which the 'S' domain transfer function can be derived.
Is there an automatic tool that provides that ?