Electrical Engineering

6:00 AM

@jippie hey

7:52 AM

@NickAlexeev it clearly is a manufacturing defect and the seller evidently was using it fine for !many years on his CPU... So there it probably isn't much of an issue

8:10 AM

The cooler itself had a good reputation and its really hard to break them, so not unreasonable to expect it being useful. And its condition is likely about the same as when the previous owner unboxed it 5 years ago

8:33 AM

I fell into the Lava

Pandya

9:19 AM

How this site differs from engineering.stackexchange.com/questions/tagged/… ?

Not wasting my life or anything

A: Does the Rigol DS1054Z have a "integrated 2 channel waveform generator"?

9:49 AM

Apparently you can copy somebody else's comment [that answers your question] to the answer box and get up-votes for it!

I think you're having trouble reading Amazon listings. It doesn't say that, in fact the Q&A section says it doesn't. Other more expensive scopes in that series do. The question is somewhat O/T for this board anyway. — user44635 2 hours ago

1

Apparently, only the DS1074Z-S has the waveform generator. You can find the same bad verbiage in Amazon's listing on the DS1074Z too, The DS1000Z Series is the new economic level Digital Oscilloscope from Rigol to meet the customer's applications with its innovative technology, industry lead...

11:03 AM

I probalby can't ping @Arsenal here, but while I was trying to figure out TI's favorite method of simulating opamp [in]stability, I found this e2e.ti post, where the TI employee says he hasn't head of Middlebrook. I guess Caltech is farther from Texas than from Japan.

@RespawnedFluff I am wondering how people that have to ask this can manage to buy food that will not kill them

Q: What does 'fixed-bias', 'emitter-bias', 'self-bias', 'voltage-divider bias' etc. mean?

Should we also tell him what "etc." means?

-1

I am learning DC/AC biases of BJT and FETs, and these terms come up without explanation of why they are called as such, meaning a hard time remembering which is which. What do these mean? And what do I look out for to realise which type of circuit these are?

@RespawnedFluff I once overheard some exchange students from the us trying to 1up each other on how low the radius they came around so far was, the proudest one was from a small town who only ever got into the next city for school but never visited any other place there

@RespawnedFluff but only with another word at the end he needs help with

11:31 AM

math.ucr.edu/home/baez/crackpot.html is quite a nice reading

@RespawnedFluff He says he doesn't know the Middlebrook method he used, and to be fair, I had to think hard before it rang a bell, because you're dependent on your course material/prof/manual also stating that what you're doing is the Middlebrook method. Which is more likely, in fact, in honour driven countries, I'd say it's more likely to be mentioned

@PlasmaHH We may have to turn this into a clickable scoresheet and crapotometer

And then add other fields

11:52 AM

Can I flag my own post for a moderator so they delete it and I can retype it without my clear attention deficit problem while writing it? ^^

@Asmyldof you can flag whatever you want ;)

Careful or I'll flag you

Whatever that means

I think I found a way to success ... picayune.uclick.com/comics/ga/2015/ga151127.gif

@PlasmaHH I've been trying that. Unfortunately my plan is a great success

12:08 PM

anything differnt on that sd card while it is running?

12:50 PM

@PlasmaHH I have a few moments of meh before I dare continue that

@Asmyldof I will probably have a few meh moments at the weekend to inspect the mess of motion detection lighting that "electrician" installed at my mother in laws houses... he couldnt manage to make one ever go out and just "well, cant get it to work, going home now"

@PlasmaHH yay

she wasnt really good at explaining where it is and how the conditions there are, but I think its as simple as needing to block the street lights hitting the sensor

or at least, I hope so

otherwise I am probably lost as my experiences with PIR senors are nada

2:19 PM

@PlasmaHH Might be, but may also not be.

4:04 PM

What do you people think of this question? It's off-topic on Hardware Recommendations - would you take it here?

4:39 PM

@ArtOfCode nope, we dont do any shopping/recommendation or similar things here

@PlasmaHH cool, thanks

also is it really offtopic there?

I thinkt he last time I looked up the rules it was more or less "anything technical to get the job done" and while a lot where about PCs there was also quite some about other things

if it where, the site should better be renamed to "computer hardware recommendations"

@PlasmaHH It basically is computer hardware recommendations. It's defined by this post‌, if you want an exact definition.

@ArtOfCode then really a rename should be considered... or at least put it in the summary of the "Tour" site (which most people don't really read anyways)

@PlasmaHH I think we have got it in the information somewhere. Renames are basically out of the question, unless there's really strong evidence that the current name is actively harming the site.

4:48 PM

@ArtOfCode I can't find it when quickly looking through the "Tour" and honestly when reading just "Hardware recommendation" I would not immediately think of "Computer related only" the same way I would not buy a computer in a hardware store..

@PlasmaHH Noted. I'll see if I can find a moment to update the tour.

@ArtOfCode also hardwarerecs.stackexchange.com/help/on-topic which says "That means you can ask for a recommendation for hardware to perform a specific task." which suffers from the same definition problem.

Probably for you and others in the community it is clear "what else could 'hardware'" mean but probably not so for many other, especially lots of non native speakers

unless of course you want to go the route of DIY.EE which I just discovered is north american only, basically.

@PlasmaHH we do have folks who deal with UK/Euro conventions on DIY.SE as well, we just don't have nearly as many as we do folks familiar with US electricity

@Shalvenay its just that you are receiving some "oh, you are not in the US, you should have said that you are a foreigner and everything is not normal in your case" attitude quite often there

@PlasmaHH we generally encourage people to mention their locale on electrical questions -- even within the US, it's still important! (local code variances abound)

4:59 PM

@Shalvenay not talking about electrical questions here, just things like drilling a hole in the wall

For electricity it should be rather obvious that there are a lot of regulations out there, but I think its too much asked for to get familiar with all kinds of possiblities of walls and how you have to distinguish what wall you are talking about

@PlasmaHH well, drywall can hide some things :) steel studs are particularly persnickety, because they don't hold wall-mount things up nearly as well as wood AIUI

@Shalvenay well, when you live in a country where (and with a lot of counries around it) you almost never encounter drywalls, then its not so easy to think of them being a possibility.

@PlasmaHH aaah, all-masonry where you're at?

Just like it would be uncommon to encounter a 11kV cable when talking about electricity...

@Shalvenay germany

@PlasmaHH nods yeah...definitely the land of masonry galore then. mass walls work, they're just a bit annoying to insulate :)

5:07 PM

@Shalvenay not at all, besides insulating itself already better than a bit of plywood ;) you whack whatever is the hype this year on the outside. styrofoam is quite common these days

but there a commetn again, boiling down to "you have no location information so I assume you are in the US"

anyways I need to go home now, the wife is getting impatient

5:28 PM

@PlasmaHH thanks for your feedback, I've made some changes to the /tour and /help/on-topic pages.

@PlasmaHH yeah, closed-cell foamboard is wonderful stuff :)

6:06 PM

@Shalvenay my wife recently did some construction with VIP panels, wonder if that got built

jippie

6:16 PM

> What is the connections for a USB-VGA connector?

sigh

Q: Why this pair of IGBT's died silently?

@jippie indeed

jippie

I'm getting depressed from the review queue and some of the questions that haven't been close-voted yet.

Today's Darwin award nominee:

2

0

Before some days I have taken a look at circuit which controls AC current's frequency. That circuit was a VFD which looks like: simulate this circuit – Schematic created using CircuitLab But this circuit is for controlling 3 Phase motor. So, I tried to make a similar one that can control...

arduino igbt vfd

We should really change the off-topic guidelines

Nick Alexeev

9:49 PM

@jippie A non-frictionless admission system** for new members would be more effective at dealing with this.

** for example: quarantine, picture of the oscilloscope, etc

Q: Inverse Laplace transform: is there a nice formula for the step response of a 2nd order system?

11:04 PM

Laplace, sigh...

0

For the impulse response of a 2nd order system given by $$ H(s) = \frac{\omega_n^2}{s^2+2\zeta\omega_ns+\omega_n^2}$$ I was surprised to see there exists a general formula found by Wolfram Alpha for its inverse Laplace transform: $$ h(t) = \frac{\omega_n^2}{\sqrt{\zeta^2-1}}\exp(-t\omega_n\ze...

laplace-transform

11:29 PM

Sorry to disturb you all

I'd just like to know if I can use a speaker cable as connecting wire for a breadboard

e.g. maplin.co.uk/p/…

Thanks in advance

@Leuchte Not well because you need to tin the ends. If you're gonna appropriate something, networking cable works well enough as-is... and I usually have too much of that.

@RespawnedFluff Thanks for your response, just another question: can use this breadboard like a normal breadboard or does it require soldering - I'm a little confused (maplin.co.uk/p/…)

@Leuchte 99% certain it requires soldering.

I see :)

In fact given the "Perma-Proto" name, 100%.