I started working on the resistor cube problem that we started thinking about in the resistor grid thread. Here are some results:

Code (Text):

- Resistor Mesh Cube
- ------------------
- N V R
- 1 4.000000 8.333333
- 2 3.255814 10.238095
- 3 2.967581 11.232493
- 4 2.813628 11.847100
- 5 2.718043 12.263726
- 6 2.653020 12.564298
- 7 2.605965 12.791168
- 8 2.570354 12.968384
- 9 2.542474 13.110588
- 10 2.520060 13.227196
- 20 2.418082 13.785033...

Now spiral a wire about this N times, evenly spaced.

What is the length of this wire?

My approximation is probably close enough, but I wonder if there is a simple answer to this.

(Note: I am NOT planning how to light my Christmas Tree. No, not me.)]]>

View attachment 140628

View attachment 140629]]>

i have been given the following:

Voltage = 100v phase angle 0° at 20hz

Current = 1.5A phase angle -30°

Capacitor = 50μF

any help would be much appreciated

many thanks]]>

I am trying to find an expression for the output voltage of my Royer oscillator. I have attached the oscillator as a file to this post.

I understand how the system works in practice and theory. However I need some help finding an expression for the voltage across L4.

Thanks!

Kasper]]>

View attachment 140458]]>

On the way back to the table, the waiter ponders on how he is going to split $5 three ways.

No problem, he thinks. "They think the total...

Another math problem (fun)]]>

I took an embarrassingly long time to figure this one out.]]>

View attachment 136466

and the y=x in semi logarithm is

View attachment 136467

what is the equation of above curve?]]>

From experience with common graphs about this subject, the left to right line is usually always the direction/angle/etc. not the amount/magnitude/etc.

Am I reading correctly where it says "The length of the vector represents the magnitude (or amplitude) of the waveform.." in the link above...

Vectors and definitions headache]]>

Question and a0

View attachment 134443

an, bn, f(x) and plot

View attachment 134444 View attachment 134445 View attachment 134446 View attachment 134447

Following the general equation as quoted from various reputable sources, such as John Bird, View attachment 134448 although the...

Fourier equation for given part of cos function between -pi and pi]]>

In the example on the image, there are 3 nodes on the horizontal axis (Nx=3), and 14 nodes on the vertical axis (Ny=14), but I would like to know if there is an analytical solution for any numbers of nodes along both axes (for any Nx and Ny).

The solution for Nx=1 is quite trivial, it is simply: Req=Ny*R.

But do you think it is...

Honeycomb electrical circuit]]>

For those that like solving networks here is a not too difficult one that only involves resistors and a single voltage source. However, there are a lot of resistors

The resistors form a nice symmetrical grid too.

So see what you can come up with, and see if you can figure it out in whole or in part without actually calculating too much, or if you feel you have to calculate a lot then go right ahead and do so. I can assure you it is interesting.

In this simpler example,...

Resistor Grid Voltages Challenge]]>

In step #4.....why would they multiply the second term by 8 and not the next sequence....which is 4?

http://www.dailymail.co.uk/femail/article-4702868/Can-pass-intelligence-test.html#ixzz4n94x1UzS]]>

for values of p near 0.5.

The exact solution is

But if D is large, then calculating the ln() in the denominator is problematic.

So I can think of two approximations that should be valid when D is very large (as in something like 2^256).

The first is the approximation that

Why don't these approximations seem to converge?]]>

Thanks in advance.]]>

as image are store in matrix form]]>

Unfortunately, the rules seem to be rather vague (they read like the IRS tax code) and I'm still not completely clear what actually constitutes a significant digit. My understanding is that significant figures refer to the known accuracy of each digit to the right of the decimal point.

For example, if a caliper in a machine shop can accurately measure to 1/1000 of an inch and it measures the...

Question About Significant Figures]]>