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Hello, i have questions from a book that I'm reading, it's full of interesting problems about Electrical Engineering. For now i want to ask about op-amp offset error. I will post a copy of the problem here. We can talk about it, i have an idea about offset error so i can share it here later...

Hello, I would like to ask if it's possible to send assignments from book that I'm reading: Ten Essential Skills for Electrical Engineers This book is quite interesting , sometimes i solve its assignments but i find it quite challenging. Can I send regularly and discuss about it? I'm an...

I'm interested in analogue electronics in general. There is a book I liked named: Ten Essential Skills for Electrical Engineers by Barry L. Dorr. I've been reading it, somehow it's quite comprehensive and includes almost everything in clever way. I would be glad to have someone discuss with...

I just have Electronics Engineering diploma. Currenly I'm not involved in any school, actually I'm not from here. I live in Europe but I'm not participating in scientific activities, I'm just working whatever. That's why I decided to write here, perhaps to meet friends and discuss about Electronics.

Hello, I'm just open to new ideas about Electronics. For some reason or another, I loved this community. I want to participate in discussions about Electronics but I want something constructive, new ideas. I'm located in Europe so it would also nice to meet with other members here and share...

By calculating manually with the same steps for h=0.2 (which is quite large as you said) I got y2(1)=2,..(something) I don't remember but i think it's still acceptable for this large assumtption of h, so the guess that y2(0)=1 was not bad I think. Yes and y1(1) is almost 0.5 which ensures that...

I don't think so but why do you ask?

So when i applied your equations I got y1(1)=0 and y2(1)=2 assuming y2(0)=1 for increments h=0.2. Which is quite logical because y1 is strictly decreasing with x and y2 is strictly increasing with x as pasmith said.

No, only numerically.

Thanks but still not clear how to step forward to the other boundary point. We have two equation, i don't know from which one to start and how. What assumptions should be made and what concrete processes? Can you make it a little bit more clear?! Thank you.

Hello, can anyone give me the general instructions of solving shooting method problem: dy1/dx=-y1^2*y2 dy2/dx=y1*y2^2 with the boundary conditions: y1(0)=1, y2(1)=2

OK, thank you again.

But I still don't understand how e^(-j*2*pi/N *2)= e^(j*2*pi/N). Are these two angles identical??

That is a very good and summarized answer. Thank you RUber :)

No i mean for each actual frequency wha are the sampling results for fs=1000 Hz and then for fs=1002 Hz.

Homework Statement We have the following signal frequencies: f1=18 Hz, f2=510 Hz, f3=1100 Hz when using the sampling frequency fs=1000 Hz. how would these signals be like? my question is if I could use the same formula stated below for all the frequencies f1,f2,f3.. because the second and...

Homework Statement We have a set of values: f(n)=f(0,1,2)=(1,3,2) so f(0)=1, f(1)=3, f(2)=2, where n=0,1,2 the number of values N=3 The question is to calculate the FFT of this signal, the Fourier spectrum the power spectrum and phase spectrum. I'm not sure concerning FFT. And also about...

$$ y''' = f_{xx} + f_{xy} y' + f ( f_{yx} + f_{yy} f) + f_{y} (f_{x} + f_{y} f) $$ which leads to the final result.

Hi all, I need to understand these differential equations specially moving from the second order to the third order because i couldn't understand how they got to the result, what was exactly the principle: $$ y'=f(x,y) $$ $$ y''=\frac{df}{dx}(x,y(x)) = f_{x}(x,y) + f_{y}(x,y)y' = f_{x}(x,y) +...

Dear Mark44 and rubi, thank you both for providing the information. It was very helpful. Thank you very much indeed! :-)

the equation was actually $$ \lim_{n \to \infty }n\int_{0}^{1/n}f(t)dt= \lim_{n \to \infty }n\frac{1}{n}f(0)=f(0) $$

Hello, I passed by this integration and couldn't understand the moving from the left hand to the right hand side. $$ \int_{0}^{1/n}f(t)dt=\frac{1}{n}f(0) $$ could you please tell me why this is??

I think this script can work very well for my example: http://www.physycom.unibo.it/bazzani_web_dir/modelli_numerici/algoritmipde.pdf

I would prefer to use the set of coupled odes as was in the example of my textbook. But it can also be any method that make the solution easier so i don't really know! If it's less difficult to solve it by single ode then i would go for it also. I'm not sure which one can go work better for...

the example was a single ode!

I will tell you, I applied Crank-Nicholson directly to solve the second order..as some examples i read in some textbook but the examples were solved there in a completely different way that's way i had problem.. I'm familiar with the idea that you said but not sure how to apply it to this...

yes, so what are you aiming to?

Thank you for the reply Bigfooted. I'm familiar with the numerical methods. I have applied the crank-nicolson relation so after many corrections I had some formula. But still I'm confused about how to move forward. Or maybe I don't remember verywell when it comes to more difficult tasks. I'll...

Hi, thanks for your reply. I haven't programmed it in MATLAB yet. But I'm not familiar how to solve it generally and how to hav the final formula for the solution so then i would start programming. The main is how to get it resolved. That's the point.

Hello, i'm willling to solve partial differential equation of the form: dy/dt = d2y/dx2 + 2/x * dy/dx - 4y where d here means partial derivation of course. boundary conditions are: dy/dx(0,t) = 0, y(1,t) = 1, t>0 initial condition is: y(x,0) = 0; (x,y) is position and t is time. and...

I know but I thought this is only an informal answer :)

Hello, we have the following example: Assume that (y1,y2) are discrete valued and follow such a distribution that the pair are with probability 1/4 equal to any of the following cases: (0,1),(0,-1),(1,0),(-1,0) . E{y1^2*y2^2}=0 E{y1^2}*E{y2^2}=1/4 I don't understand how the...

hello I'm there

Yeah,it could be a good idea. Can you send it to me please? Thanks.

Hello. Does anyone here have some resources about "probability and statistics for biomedical engineers" or "probability theory","random processes" ? I do need it. Thanks in advance!

Yeah. I think that i need such "fundamental" descriptions to those topics. Anyway let's see...we might want to discuss more thanks

I will try to get these books. Thanks

Hello. Any good resources which include general information about : 1- Bioelectric signals 2- Physiological transducers 3- Electrodes 4- Biopotential amplifiers for ECG (electrocardiograph),EEG(electroencephalograph),EOG (electro-oculograph).

Hello. I need to know the mechanism of drilling my printed circuit board (PCB) with two step motors x,y using microcontroller. How to use eagle or orcad to control two step motors to drill and how can the microcontroller accept the eagle file to locate the coordinates of the driller...

I need a clarify for this statement: Replacement of galvanometers with high-gain amplifiers allowed smaller electrodes with higher impedances to be used and potentials of smaller amplitudes to be recorded .

This is really amazing. Thanks.

Well,that's right. I tried to look up for that in german universities websites and using google but was of no sense.I haven't got the exact info i need. So i found this forum (physicsforums) is a proper place to post in since it has a variety of subjects discussed and many members seeking for...

Hello.I don't know if anyone can help or even guide me. reagards

Well, I studied electrical engineering at university in which we learned a lot of math as pure mathematics. The doctors and assistants were always saying that we do need mathematics in our engineering problems. The real problem for us is how we can use mathematics in such engineering or...

Hello. I can't understand some things in these two files attached with this thread. Firstly,in file "image 1",i don't know about the method of least sequares mentioned in equation 47. Secondly, in file "image 2",from where the equation 52 comes and how do we get the next equation 53. I...

Sorry if i change the subject somehow. I'm going to do postgraduate studies of medical electronics in germany, so does someone know which univeristies offer this sort of studying and its ranking.

Hello.I actually didn't know exactly how do we get to the second line with this integration.

I wrote this instruction: Needs["`Nodal2`"] but I had the warning messages: Cannot open Global `Nodal2` Needs::nocont: Context expr was not created when Needs was evaluated. I really would like to know what is the matter!

thank you,i will try what you have said but i also have been wondering about NodalNetwork,it didn' work once with me and i don't know why. we'll keep in touch anyway many thanks

I frequently get this warning message from mathematica: yntax::tsntxi: "Out:" is incomplete; more input is needed Does anyone here know about this kind of message ,,,why does it occur? Even that i read from help about it i didn't find any mistake made by me or...i might be wrong...