LC filter help need information

[yassin.kraouch]

Hi all, can you please share me some courses on the design of LC filter ? if you have some courses or paper ?
i need this information soon

 

[Darktrax]

Here is a link to a free tutorial on LC filter design.
HERE --> **broken link removed**
There are many tutorials, and also free online tools where you get the calculation done for you - but to understand the the design, you at least need the tutorials.

 

[Rohitchampion]

Rather than asking here, u should google it. You will find many good stuff. Take down whatever you want. Try pdf or ebooks. And yes there are many tools available online too. Use them to get learn more efficiently.

 

[yassin.kraouch]

Darktrax, thank you for your reply, it is really helpful, can you please send me a link of free online tools for calculation ?
Rochitchampion, yes i know to google, annd i google it but i didn't understand anything, please if you can help, and i don't need such a remarks

 

[BradtheRad]

Not all considerations are intuitively obvious. Nor are they brought out in tutorials.

Of course we have the standard formula for center frequency (which is independent of resistance).

There is the Q factor, which is associated with bandwidth. (This depends on resistance.)

And it makes a difference whether the LC is series, or parallel (tank). Then for either configuration, we can tap at one end to obtain a bandpass, or at the other end to obtain a notch.

There are the parallelogram shapes, created when we calculate effective impedance for coils and capacitors, for given frequency and resistance.

I believe simulations are invaluable for giving further insights.

Example:

1.

This simulation shows how Q factor (and thus bandwidth) is affected by input resistance. (This input resistance might be known or unknown.)

Five identical LC tanks. Input resistors increase in steps of 10X. A sine sweep is applied.



2.

This simulation illustrates various Q factors (and thus bandwidths), based on the ratio of coil value to capacitor value. (This is despite the fact that the combinations have identical center frequency).

Four series LC filters, with identical series resistance.
Coils decrease by steps of 10X. Caps increase by steps of 10X.
A sine sweep is applied.

 

[LvW]

.... can you please send me a link of free online tools for calculation ?

Here is a link for downloading a rather versatile program for designing passive filters:

www.aade.com

 

[Darktrax]

Here is a link to a (free) York University calculator that does not require you to install any executables on your PC.

It requires frequencies in Hz, and I had a problem with it wanting "minimum frequency", which I though I had offered. I did not spend time on it. You can maybe figure it out.
HERE -->

This one does high-pass and low-pass only.
HERE --> https://www.wa4dsy.net/filter/hp_lp_filter.html

Finally, you can try out a filter you design by entering the values into a simulator.
Linear Technology supply a (free) Spice simulator called LTspice. It is provided for users to design their switched-mode power supplies products, but is a powerful general purpose simulator you can use for anything. You get the result from simply using the mouse to place probes. It has a learning curve, but there are lots of instructions and examples if you use Google.
Again - you will have to figure out how to use it yourself. It has built-in educational examples.



HERE --> https://www.linear.com/designtools/software/#LTspice
The example in the picture is normalized to 1Ohm, and the frequencies are in milliHz. Such a filter may be transformed to any frequency.
you will have to learn what is "normalizing" and how to multiply and divede the component values to scale the frequency if you come across these.