test bandpass

Hello!
I have to build a bandpass filter, noise filtering and removing the DC component for a signal, the range is [0.5-5 Hz].

I am using the following design:
http://img199.imageshack.us/img199/2947/badnpass.jpg

Considering my available components (but I am planning
to use more coherent stuff)
Part high-pass:
C1, C2 = 1 microF
R1 = 450 KOhm
R2 = 225 kOhm
Part lowpass:
R1, R2 = 8.2 KOhm
C1 = 4.7 microF
C2 = 2.2 microF
-------------------------------------------------- --------------
Here are my questions,
1. Using a wave generator and an oscilloscope, how do I test that the allowed band is effectively [0.5-5 Hz] ? What differences should I see if I send as an input a square/triangle/pseudo-sinus wave inside and outside the band ?

3. I need to avoid dual supply amplifier, 'cause the rest of the circuit is aa single supply. Assuming I have some LM386 and LM358, is it correct to just use the bottom circuit in the picture I posted ?

4. Considering I want to filter a signal coming from a photodiode and a transimpedence amp. removing noise and DC component. Can I stick with the filter I posted, or should I investigate more about Butterworth, Bessel and so on filter .... ?

Can I kindly receive an explanation why my questions were moved in HOMEWORK HELP ???!?!?!!?
I can understand that for some of you some of these questions are really easy but for me they are not!!!!!!!
And browsing among the threads I don't see a big difference between my questions and the questions of the other users!!!! I FOUND THIS BEHAVIOUR REALLY OFFENSIVE.

After a Msc in Informatic Engineering and a Ph.d in Applied math for medical imaging, I don't expect to be a genius of electronics because it is just an hobby and I am here to learn. But I found difficult to learn if someone discriminates me for some reasons. Is there a not clear motivation in the rules of the forum ? Can I have explained which part of the forum agreement did I violate ?

Best regards

Hello,

I do not know who moved it here.
You can simulate the responce in some spice programs like TINA-TI or LT-spice:
http://focus.ti.com/docs/toolsw/folders/print/tina-ti.html
http://www.linear.com/designtools/software/ltspice.jsp

Both programs are free.

TI made also two nice PDF's on filters:
sloa065_filter_design_on_a_budget.pdf
sloa096_filter_design.pdf

Bertus

sunone said:

Can I kindly receive an explanation why my questions were moved in HOMEWORK HELP ???!?!?!!?
I can understand that for some of you some of these questions are really easy but for me they are not!!!!!!!
And browsing among the threads I don't see a big difference between my questions and the questions of the other users!!!! I FOUND THIS BEHAVIOUR REALLY OFFENSIVE.

After a Msc in Informatic Engineering and a Ph.d in Applied math for medical imaging, I don't expect to be a genius of electronics because it is just an hobby and I am here to learn. But I found difficult to learn if someone discriminates me for some reasons. Is there a not clear motivation in the rules of the forum ? Can I have explained which part of the forum agreement did I violate ?
Best regards

Click to expand...

As you are experienced in math. Take a look at this book http://focus.ti.com.cn/cn/lit/an/slod006b/slod006b.pdf Feel free to ask anyway if you have some problems

I don't see any other physical way to test this appart from actually using a signal generator and an oscilloscope. Both very expensive equipment, unless you 're lucky and have access to a laboratory's equipment.

The simulation is a much more reliable method of theoretical study, though.

Thank you for your reply.

Georacer said:

I don't see any other physical way to test this appart from actually using a signal generator and an oscilloscope.

Click to expand...

If you read my first question in the post, I am actually asking a specific question assuming that I have these instruments in my apartment and my lab:

- Assuming I have a wave generator and an oscilloscope.
- If I send to the input of the bandpass filter a square wave outside a the allowed frequency. What should I see if the circuit is working properly ?
I assume nothing. If I see some micro-pseudo sinusoide is it still acceptable or this means I have done some mistake in the design? This is what I meant in the original question, sorry if it was not clear.

Georacer said:

Both very expensive equipment, unless you 're lucky and have access to a laboratory's equipment.

Click to expand...

Not really, I am sure you can find some cool and in good condition Tektronix even on Ebay for less than 1000 euro. Take a look
About the wave generator, even the good one are no more than 100-300 Euro. And you can find also good stuff for less than 100 Euro, depending what you need.

t06afre said:

As you are experienced in math. Take a look at this book http://focus.ti.com.cn/cn/lit/an/slod006b/slod006b.pdf Feel free to ask anyway if you have some problems

Click to expand...

I am not sure it contains the answer I need but
it seems a nice text thank you,