Recent content by manzana

On a related note, the impedance of nothing(free space) turns out to be about 377 ohms! I always thought that was amazing. I guess it got decided in the Big Bang and has served us well. Kind of like PI...

These are some of my favorite myths I have encountered in my EE career... 1. NEVER mix Duracell and Eveready batteries in the same flashlight 2. Never leave your car battery on a cement floor, it will ground out and drain itself ( A metal shelf on concrete is OK) 3. Never use a wireless phone...

Good question. What is your circuit? Normally you would put a bypass capacitor across the battery to keep AC out of it. Chances are, I don't understand the problem.

SciLab? It's like MatLab... but it's free. I love SciLab...

You guys are awesome. Thanks

Wow, thanks for the insightful reply. I think I get it at a particular frequency, but these devices are amazingly broadband. For example, there is one for $9 on Ebay which works from 5 Mhz to a Gig. Thanks Sophiecentaur.

Sorry! Yes, for 35 years I have wondered how these things work. I asked a pHD but he said it was too complicated to explain. thanks

These things are pretty amazing. Very cheap, they are a 3 port device which basically works like a diode, but for AC. For example, it let's a signal pass from coaxial connector A to coaxial connector B but not B to A. There is also a third coaxial port C which passes C to B but not C>A or B>C...

So, do you have 240 coming into your house ? Here in the US we get 240 3 phase which appears as 120 if you look at either of the hot sides versus neutral (ground). Anyway, I assume your breaker box is grounded and so is the water tap unless the pipe is plastic. So it is strange that you would...

Thanks for the reply. This is for a remote sensing application with very limited power available. A PC is not an option but I do use it to verify my code. I am using a very low power (battery supplied) micorcontroller. I need to do a 512 point autocorrelation every 5 seconds and the brute...

I need to do a realtime 512 point autocorrelation for a seismic project but my poor little Parallax computer is getting swamped by all the floating point multiplies. The answer seems to be in the fast Walsh Transform. I bought some IEEE papers on the subject but they are a little deep! Does...

Oh, that is really pretty neat! I am used to looking at a point while time marches on. Since Hspice never lies (ahem) this is of course correct. You are seeing how mother nature propagates the signal down the line. If it wasn't for the little LC's you would just have a voltage divider with a...

I think phyzguy is probably right. But I don't understand your graph. Are we looking at a single point on the line as the pulse goes by? Then why is it a falling edge? Are we just scanning down the line after the pulse settled out? Remember that we will get a + reflection off the end of the...