Hi all,

does anyone know any good calculation software out there (say, I enter resistance and capacistance and get low/high pass cut off frequency)?

If not, I think of writing that kind of small application. It could have:

• Low/High pass filter cut off calc;
• Ohm's law calc;
• etc..

The main point is to enter values into input boxes and get the result after you press "calculate" button, not after inputing into regular calc: sin(a + b / x) * blah^43 etc.

YOu could just make an excel spreadsheet if you're too lazy to enter the sometimes long, repetive calculations rather than an application.

Vobla,

You want to design filters. Try this. It is also good for frequency response of amplifiers.

http://gradllc.com/IMAGES/RCLgrid-1.pdf
Here is graph paper for RCL filters.
Left side is resistance form 1 ohm to 1meg ohm.
Red lines are for Capacitors.
Blue lines are for Inductors.
Black horizontal lines are for Resistors.
Black vertical lines are for Frequency.

CL resonance:
Example: Follow the .1uF line from the top left corner down across the page. Find the 100mH line and follow it from the bottom left corner upward. Where they cross is the resonant point. 1.6khz.

Cx:
Follow the .1uf line. 1k ohm at 1.6khz.

Lx:
Follow the 100mH line upward. 1k ohm at 1.6khz.

RC low pass filter using 1k and .1uf:
Start out at 1hz at the right side of the graph and at the 1k ohm point. Go right until the 1k line intersects the .1uf line. Follow the .1uf line down. That is the frequency response of the filter.

I usually printout the graph and draw on the page. There is a detailed version at:
http://gradllc.com/IMAGES/RCLgrid3.pdf

Good luck.

This might help you. John

http://focus.ti.com/docs/toolsw/fold...lter-calc.html

Hi again.

That was not what I has in mind:

• Spreadsheets - was not designed for that, has ugly interface and why use application whitch reserves more PC resources than average program for simle calculations;
• pdf stuff - good, but not multi-purpose;
• websites - seen loads of these. You need internet and it takes time to find what you need..

I appreciate your answers, but I was asking does anyone know desktop software for that?

I like fdatool personally.

I'm not buying MatLab just for a few specific calculations.. And they've got really funny statement on their homepage: "MATLAB® is a high-level language and interactive environment that enables you to perform computationally intensive tasks faster than with traditional programming languages such as C, C++, and Fortran." How come high level programming languages are faster than low level? That's bullshit to fool consumer.

Anyway, thanks for opinion

Originally Posted by erosennin

"A high-level programming language is a programming language that, in comparison to low-level programming languages, may be more abstract, easier to use, or more portable across platforms. Such languages often abstract away CPU operations such as memory access models and management of scope... Rather, "high-level language" refers to the higher level of abstraction from machine language" - Wikipedia

Totally agree, but don't forget that compiled codes are executed, not the ones programmer writes in his programming tool. So the more abstract language you use, more trash comiler adds to the compoled result. The higher level programming language, the slower/bigger compiled application :P

Try this one...
http://www.geocities.com/robert_lacoste/freewares.htm

So, you want general purpose electronic calculating software that runs on your desktop, is easy to use, was written in something other than a high level language, and does not require a net connection.

I use LTspice, which is probably not what you want. Except for ohms law calculations, which I do by inspection.