Recent content by nand_1

Thanks Kreil, realized this later on after the post. Thought it was an issue with the way i was using the feedback function.

Hi All, Suppose I have the following system: A = 1 / (S + 1) (open loop) B = S / (2S + 1) (feedback path) I know that the positive feedback closed loop system will thus be: A / (1 - AB), and entering this manually in MATLAB (as well as doing it by hand), I get: 2 s^2 + 3 s...

Hi, I'm sure there is a simple answer to the following question that's got me thinking lately but I'm unsure (it's more of a hypothetical question out of interest and not homework). If a simple older type fixed speed wind induction generator was connected directly to the grid via a gearbox...

Hi Pythagorean, I found a simple solution that works for me. Inside func2 and just before line "[t, x, te, xe, ie] = ode45 ( @de, [t0 tf], x0, options );" i record the internal CPU time. Inside function 'de', i check the new CPU time against what was recorded initially, and if 'x' seconds...

Hi all, I'm having some issues with Matlab. I'm running ode45 inside a function which is called repeatedly in a finite loop. As it is being called, Matlab is plotting and saving the data externally. Here's a quick pseudo-code func1 ( ) loop { data = func2 (variables) save...

Thanks for that Sylas.

Sorry about that I worded it wrong but that definitely makes sense. Basically I want to calculate the path in a 2D plane, however, there doesn't seem to be an easy way of doing this for time varying perpendicular acceleration. I have plotted the path taken in a MATLAB but i was just wondering...

^Bump^

Hi, If i had a point mass moving with a velocity V in a certain direction (with constant speed), and a constant acceleration (or force) was acting perpendicular to it's velocity vector. From my understanding, the point mass' speed will not change, however it will begin to take a circular...

Hi Skpetics, thanks for that. I tried the LM324 and it does saturate -ve & stays there after 1.5 periods of following the input. It does seem like a PSPICE modeling problem. My version is 9.2 non student edition. I am also using transient analysis.

Thanks for the reply guys. I guess it is pspice modeling problem. I was under the impression that the pspice opamps were accurate models of real world components. What is your voltage source amplitude set to? The circuit i drew up is at 3v.

Yes both those methods work (schmit trigger like output) but my problem is why doesn't the first method work? I would have thought that being in positive feedback configuration, even a small amount of voltage in the input (+ve or -ve) would cause saturation at +- 10V?

I'm just wondering, if an op-amp is connected in a positive feedback configuration, should the output not saturate immediately? Here is an example circuit i made in pspice along with its input/output curve (V12 has amp of 3v). http://img689.imageshack.us/img689/1286/posfeedback.png As...

Hi Guys, Thanks for the great explanations, i really appreciate it. It all made sense.

Hello all. I was just wondering if it is possible to use an inverting opamp configuration with feedback to regulate an output voltage V0 without the use of BJT's? For example, the following sketch: http://img411.imageshack.us/img411/2389/opamp.png V0 = Vs * (R1-R2) /2R1 Mathematically, V0...