I learn that we can expand the electric potential in an infinite series of rho and cos(n*phi) when solving the Laplace equation in polar coordinates. The problem I want to consider is the expansion for the potential due to a 2D line dipole (two infinitely-long line charge separated by a small...
I guess this is just a maths problem about algebra. I'm learning to solve Schrodinger equation numerically, and right now I'm just dealing with the simplest examples like harmonic potential, square well, etc. The problem is that sometimes my program gives some strange results and I suspect it is...
In class I learn that we can get the dispersion relation for particles by using E=hbar*w and p=hbar*k. The calculated phase velocity is w/k = hbar*k/2m, while the group velocity is dw/dk=hbar*k/m. All these make sense to me, except one thing: I always thought that E=hbar*w=hf is only applicable...
Suppose I have already found the surface normal vectors to a set of points (x,y), how do I compute the surface height z(x,y)?
Basically what I have are the normal vectors at each point (x,y) on a square grid. Then I calculate the vectors u = (x+1,y,z(x+1,y)) - (x,y,z(x,y)) and v =...
I am doing a project on image processing and I need to solve the following set of equations:
nx+nz*( z(x+1,y)-z(x,y) )=0
ny+nz*( z(x+1,y)-z(x,y) )=0
and equations of the boundary (bottom and right side of the image):
nx+nz*( z(x,y)-z(x-1,y) )=0
ny+nz*( z(x,y)-z(x,y-1) )=0
nx,ny,nz is the...
I'm still not sure what 'real time' means, but if u throw any diff eq of the form y''+by'+cy = f(t) to me, I can solve it using my circuit provided that the values of coefficients are not too extreme
I tried other values of resistance and capacitance for the integrator, but 100k ohm and 0.1uF seems to work best. If I use any other larger resistor (~1M ohm), the output signal is just to small to be seen on the oscilloscope). Since y'=-100*integrate(y''), and...
I finally manage to get some output signals that I suspect are correct both in LTSPICE and in my actual circuit. My circuit is the same as yours, except I remove the inverter for f(t) as it merely have a pi phase shift for the forcing function. It shouldn't affect the amplitude of the...
thanks for all the replies so far. Solving first-order diff eq is not a problem, but the problem is still the 2nd-order diff eq. I just try to have two integrators connected together, hoping that it will integrate the input signals two times. Suppose the input signal has the form sin(wt), then...
I have an idea: have two square wave output signals from the same function generator, and introduce a phase shift to one signal. I should get zero output when the two signals have opposite signs, and the amplitude should double when the two signals have the same signs. Does it work? But I need...
I guess the generators in my lab don;t have the function you mentioned. I asked the demonstrator during the lab, and he said all I could do was to use another model of function generator that produced +ve and 0 output alternately, but this is still not what I want as I need a narrow 'spike'.
Basically I want to test my analog circuit using a forcing function that has a form of a delta function. The function generator I use outputs sine wave, triangular wave and square wave (+ve and -ve output in one period). Are there any ways to produce a square wave that has an output for like 5%...