Recent content by eman3

Thanks! How did you derive that?

I want to determine how large a magnet I need in order to get a given field a certain distance away from the surface. An N48 neodymium magnet has a Bremanence of ~1.47T. How does the physical size of the magnet affect the field a given distance away...

I'm not really sure what you're asking, nor am I really sure I'm the person to give you a definitive answer... but this seems like it might help: http://www.avx.com/docs/Catalogs/cbasic.pdf Equation III relates the current to the capacitance and dV/dt, and capacitance contains the...

mfb -- thanks, but I'm looking to figure out V(x,y). Your equation gives me an idea of what voltage measurement I might get as I vary the measuring point along the x-axis (assumed to be a straight line between the two wire probes). But what happens if I vary the measuring point along the y-axis...

Thanks. Having failed DiffEq twice when I took that class, is there e.g an online tool that will generate a nice graphic showing how the solution looks? I don't need a precise solution, just an order of magnitude estimation...

DragonPetter: That would be nice, but what little PCB space there is already quite fully occupied, by which I mean jam packed. (It's a sensor to help improve the efficiency of power plants in 3rd world countries. It has to be simple and tiny enough that the end users can retrofit it into...

DragonPetter: I'm trying to figure out where some failures are coming from despite the chips all having fairly good internal ESD protection on every line that could even remotely be getting hit. The problem is the device has to be too small to do protection off the IC. Yungman: That's more or...

DragonPetter: Fair enough, but it sounds like you still had some failures. What caused the ESD protection to fail? (Anyone else have experiences with ESD protection failures? yungman?)

DragonPetter: That makes sense. What about when all exposed I/O was protected, and the failure occurred despite ESD coming in on a protected line?

Florin, I'm not really qualified to answer this, so take my thoughts with a grain of salt. That said: Dielectric constant should be related to the rate of change of current and voltage between electrode and ground plate prior to the arc discharge. At that point I think the spark plug would be...

yungman, thanks! That's pretty incredible. Have you ever looked at chips with built-in ESD protection, like DragonPetter was talking about? (capacitors and diodes to prevent overvoltage) Have you ever seen a failure despite ESD protection? How did that happen?

Hey, Assume I have a very large tank of some liquid with uniform but medium conductivity. I now insert two fine wires into the tank some distance (D) apart, and create an electrical potential difference between them (V). 1) If I were to take my voltmeter (input impedance very high, so we...

Dragon- Thanks, that's quite interesting. What happens when ESD protection devices aren't enough? (Presumably they aren't perfect, or we wouldn't get electronic components like hard drives in silver baggies.)

Thanks! The site as a whole looks like an amazing resource on semiconductor failures. Is there anything similar covering ESD protection mechanisms?

I'm trying to understand why static discharge (or just plain high voltage) damages semiconductors, in particular integrated circuits. What happens when a chip gets hit by a voltage spike that it can't handle?