HW7 Prob 1 Different times for zener discharge

Hey everyone, I noticed that I get two different time values for the time period where the zener is on depending on the method I use (for P=100W case):

Method 1 (lecture 20 slide 3 method):
L_l = 16u I_p = 1.43
t_z = (16u * 1.43)/(500-300-100) = 229nano seconds

Method 2 (state plane geometry, annotation from lecture 20 slide 1, theta_p is the angle between r1 and r2):
r1 = 1.45 r2 = .25 and r2 = r1 * cos(theta_p) => theta_p = arccos (r2/r1) = 1.4 radians
w_o = sqrt (L_l * C_ds) = 25M
w*t = theta => t_z = theta_p/w_o = 1.4/25M = 59nano seconds

Why do these not match up? I used state-plane geometry to get all the other times for my graphs, but now I am doubting these values. What am I missing?

MATLAB graphing in HW7 Problem 3

Hi class,

I'm very bad at MATLAB to say the least and am having trouble graphing the equations in problem 3. We're supposed to graph similar equations to what is shown in slides 13 and 16 of Lecture 22.

Right now I am rearranging the equations as J = ........*M and then using plot(M,J)

However, it is very tedious and I am not sure my graph is correct. Is there a simpler way to graph these equations? If you could point me to some MATLAB references that would be great.

-Rob

HW7 prob 2

Hello everyone. I need some help.

Part a. Is anyone else calculating a vertical line at pi-2 for mc vs jl?

Part b. From the lecture notes gamma=2pi and J=2/pi. Here is what I've calculated for the rest. Mc1=2, Ma2=3/2, Ma1=1/2, alpha=undefined and beta=undefined. Does this sound correct? I'm assuming the sketch will be a horizontal line at J=pi/2.

Thanks for the help.
-Joe