how to start designing filters in labview?

[digu]

Hi,

How can i get started with designing of bandpass filter without using add on kit? 

[Mathan]

In your other thread you marked t06afre post as solution and you told doubts are clear, then why you started other thread with the same topic?

Mathan

[Coq_Rouge]

What do mean by designing filter? Please clarify your goal. Else we can not help you with your project. I have already given you some hint. But somehow I feel that was wasted time, and I hate wasting my time, like everyone in this forum.

So please take some time and give us enough details to understand what you are doing in your (school) project. You do not have be ashamed for asking for help in a school project. But Now you are spoon-feeding us with your project details using a small teaspoon. This make it very hard to help you 

Which type of Labview do have? Is it base, or a more advanced version

Message Edited by t06afre on 03-20-2009 12:32 PM

[Mathan]

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t06afre wrote:

and I hate wasting my time, like everyone in this forum.

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Dear t06afre,

Why you said everyone? This is not fair.  Even if you are not acknowledging others' helping tendency please don't comment like this.

Hope you understand.

Thanks,

Mathan

Message Edited by mathan on 03-20-2009 06:32 AM

[Coq_Rouge]

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mathan wrote:
Even if you are not acknowledging others' helping tendency please don't comment like this.

Hope you understand.

---

I can not see anything wrong in commenting like this. And I certainly acknowledge others helping, as I enjoy helping my self. But I to often feel my help is like a shoot in the dark because the original poster is holding back details. Or even worse not interested in help, but rather a complete application the can slap on a name sticker and deliver as their own homework(this do not apply to you kr.Digvijay ). I such cases a direct manner of speaking is in place. I have noticed that you are the first to comment duplicate posting. It is more or less the same thing.

Best regards

T06afre

[digu]

Hi.

well  the solution given earlier did not work for me n i am totally messed up what to do next.. I tried what was told to me but still no desired result n thats why i started fresh thread so that i can get some help n start designing from the begining. It may be possible that earlier I started of wrong,so this time i'll start from simple design n thn move to complex one..

The application is that" I have to design a bandpass filter used as Preamplifier,input to this is a sound wave(in mV),at the output i need signal in micro volts." how this is to be done that i m unable to find out. 

[digu]

It may looks simple to most of the people but being a beginner in labview m finding it somewhat difficult. I m using 8.5 (trial)version. so,if anyone have patience to clear my doubts,thn plz help me.

[Henrik_Volkers]

So, for a restart

You want to bandpass a signal...  and you didn't get the expected result...   so more information is  needed:

Samplerate

BW of signal

BW of BP

what is the signal?

What do you expect? 

Digital filters can do a lot, however sometimes the processing can be tricky ....and sometimes they have to fail :-0

[digu]

Hi Henrik,

Thanks for ur concern. Here is the info u have asked for:

Samplerate= 4500 hz

BW of filter = 100

Center frequency 2250 hz

signal is a sound wave in mili volts coming from the antenna.

At the output end, signal with amplification & filteration is desired. 

Now what I have to do next?

plz let me know ASAP. 

[Coq_Rouge]

Hi

Your filter specification is all wrong. You have placed your center frequency  on the Nyquist frequency. Your filter will never work. I guess you get some sort of error. If you are using a sound card increase your sample rate to about 44Khz.

Read more about nyquist frequency here 

http://en.wikipedia.org/wiki/Nyquist_frequency and here http://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem

I am also somewhat puzzled over this sentence

 I have to design a bandpass filter used as Preamplifier,input to this is a sound wave(in mV),at the output i need signal in micro volts." how this is to be done that i m unable to find out. 

Also tell us more about your AD/DA hardware is it a sound card or some other hardware