is there a licensure exam for electrical engineering in the US?

@IvanMatala No. And thank goodness there isn't!

Is anyone here? I have an easy question.

whats your question david :)

@IvanMatala If you look at my profile, is my email address visible? electronics.stackexchange.com/users/3624/david-kessner

Should be just to the right of the picture, if it is there.

no. i only see this puu.sh/4l1zs.png

@IvanMatala Ok, cool. Thanks. When I view it myself, it is visible. I don't know why I never noticed it before. But when I saw it I wanted to make sure that your average Joe couldn't see it.

+1

morning

@DavidKessner Ah did they fix that?

@jippie Apparently it is private info, that isn't shown to your average Ivan. So I'm safe.

Well, I'm off to bed. G'nite all!

night @DavidKessner

grEEtz all.

... or none.

Hi @Anindo

Hi @PeterJ :-)

Someone is systematically (and intelligently) downvoting my answers. Intelligently = not downvoting too many per day, so as to avoid the mass voting filter.

I wonder how long it'll take them to actually impact my rep noticeably.

morning @AnindoGhosh

@AnindoGhosh, probably a while at -2 a pop lol. I gather from a few posts on Meta.SO they do occasionally look into it (SE staff that is), but unless too bad leave it alone. Don't know about you but I think I've had more random upvotes after answering someone's question rather than the opposite so probably works out alright in the end.

Hi @jippie

hi @PeterJ

@AnindoGhosh I'm sorry but you noticed my voting pattern? ;) Just teasing, I guess Tony has a XXXX-on for you.

Just random drive by commenting.

Life got more relaxing since I stopped rep whoring ;o)

@PeterJ Yeah, I'm not fussed. Not much one can do with reputation beyond 20k on this site anyway, which is very demotivational. If I could at least do things like mark a user as a habitual spammer, or tag a user's ID for mod attention (rather than only tagging posts), I would really value the reputation points.

I don't think I'll ever see the 20k delete button

@rawbrawb No, it's unlikely to be Tony. For all his faults I've never seen a downvote on an answer of mine which went in direct opposition to one of his. Not saying it couldn't happen. People change.

So do you have any answer with negative score @AnindoGhosh? I usually blindy follow the score when voting ;o)

@AnindoGhosh I think those votes would be removed the minute the user is nuked. Not sure though

@jippie Not that I know of. But then, I often answer questions others consider below their dignity (too trivial?)... So I get the beginner votes.

@AnindoGhosh Bitterness has roots that run deep. You should see some compensatorial action.

@jippie Yeah I get that - but since I usually am up to the minute on most sites I participate in (EE.SE being one of about a dozen), I'd notice if I saw a downvote.

@rawbrawb I don't think he's bitter about me - I've been pretty balanced in giving him benefit of doubt. But if he is he is. I don't grudge him that.

@rawbrawb The one user I know is bitter about me is SHASWAT - After I called him out on his plagiarizing of answers, he promptly went and downvoted many of my answers... and then auto-reversal kicked in :-) Then he was away from the site for a while. He just came back a day or two ago. So that's where my suspicion points.

@AnindoGhosh I don't have any dignity

@jippie Yeah, I'm with you on that. There's no dignity benchmark in answering a question - if someone had the reason to ask, there's probably others with the same problem.

would a draaispoelmeter (no clue what the english word is) respond linear to PWM duty cycle variations?

an analog meter I guess ...

@jippie Moving coil analog meter. It will respond to PWM by showing the average level of the PWM signal, assuming the PWM frequency is high enough to not induce a quiver in the coil. Given the coil inertia, that could be anywhere from tenths of a second (0.1 Hz) to 100 Hz or higher.

@AnindoGhosh average power or average voltage? :-p

@jippie It's a DC electromagnetic coil - so average current.

@jippie Of course, if the coil resistance is too high, then the phase relationship starts leaning towards a power relationship instead of current, I guess.

"too high" .... ;o)

@jippie Think of it as percentages. If the resistance is, say, under 5% (figure that I made up) of the reactance of the inductive coil, at the frequency of interest, then the coil will behave reactively, with resistive (i.e. power) losses being an insignificant contributor.

Hi!

Not everyday you see a burnt lizard on a PC power-supply PCB :)

Hi folks, I want to ask you about electric-driven vacuum cups. Do you know how much is it? I want to create a prototype of automatic paper feeder that must lift a paper from a stack of papers from one container to the other containers one by one without mistakes (no two papers get lifted at the same time).

@PSTikZ Too broad. What have you worked out so far, and what exactly is it you are blocked at?

@abdullahkahraman Was the lizard's power rating too low?

@AnindoGhosh I have a problem to build the mechanical parts. Software parts are not as difficult as the hardware ones.

@PSTikZ shapeways.com and use their White Strong Flexible Polished as your material for the suction cups. If you want more rubber-like suction cups, you need their new rubber-like material. The metal parts, go to a neighborhood CNC lathe / milling shop.

@PSTikZ A halfway competent CAD designer could make you the part specifications / drawings for both the metal and the flexible parts.

@AnindoGhosh Yes. I am learning the SolidWorks 2013 and the problem is still about finding the mechanical parts that I cannot create by myself. :-)

@PSTikZ And why can you not create them all by yourself?

@AnindoGhosh It does not make sense for a short period of time.

I love this product. destaco.com/ecocup.html

@PSTikZ OK, just so I understand this: You can't get them fabbed, and you want a cheap source for them readymade to your specifications? Do let me know what works out for you, because I'm sure there is a market worth billions for that kind of stuff.

The vacuum cups should be able to lift a sheet of paper without pneumatic system.

@PSTikZ That isn't a specification, it is a wishlist entry.

@PSTikZ Do you realize that different papers have different surface porosity and unevenness? The "photo glossy light grammage" types, i.e. magazine glossy paper, is relatively easy to lift without pneumatics, as long as we're talking about really small pieces. Anything bigger, the constraint is not fabrication, it is physics. I am curious: How much do you understand of the physics and mechanics of what you are trying to do?

I know high school level physics and mathematics. C# is more than enough.

I will use netduino micro .net framework.

@PSTikZ Hmm, unless you can lift paper with C# or Jedi mind tricks, the physics of what you're trying to do is not going to work out.

The paper I want to lift is normal paper used for daily printing A4.

@PSTikZ OK, so that's even worse - Normal printer paper is high porosity low surface evenness and medium grammage. You'll need a vacuum pump.

My previous idea is to use LEGO, but now I want to build more robust one.

@AnindoGhosh But parallel vacuum cups can be used to overcome this barrier, i think :-)

@PSTikZ Work out the physics: You'd need pretty much 70% vacuum cup coverage on conventional (non-glossy) printer paper, and then too you'd achieve perhaps under a half-second of holding suction using silicone rubber cups.

@PSTikZ You do realize what that means?

@AnindoGhosh Where did you get the statement above?

@PSTikZ Google patent search gives several different passive suction cup paper lifting patents.

@PSTikZ And I've done work in this area, so the rules of thumb are in my head.

@AnindoGhosh That is good!

@PSTikZ Here, you'll need this equipment to start with: printwiki.org/Sheffield_Porosimeter

@AnindoGhosh So you want to blow air to help separate the top paper from the bottom ones before lifting?

I see....

@PSTikZ No, that doesn't work with stacked paper. That instrument will let you know how much your paper's porosity is, so you will know how much air will leak into the vacuum volume before the paper can no longer be held up against gravity. It's used for adjustment of the vacuum pump in offset machines too.

@PSTikZ Trust me, high school physics won't cut it. You'll need much more - or you could just experiment with existing vacuum cups, such as the bathroom mirror suction cup hooks you can get from stores... Just keep adding them up till you have lift long enough for your purposes, that will tell you the coverage percentage required.

@AnindoGhosh I can try with a straw... :-)

How about using electrostatic charge?

@AnindoGhosh lol, probably it was connected backwards.

@skullpatrol: Why are you here? :-)

@abdullahkahraman thanks for helping me make my point

@PSTikZ Just looking around honey :D

@jippie hahahaha

@skullpatrol Oh my ghost honey!

@PSTikZ A straw isn't a suction cup.

@PSTikZ How are you?

@AnindoGhosh Yes. And I cannot lift a sheet of paper by sucking. :-)

@skullpatrol Fine, I am very stressed to develop an automatic paper feeder. :-) You are fine too ,right?

Yes I am thank you :-)

@skullpatrol :-)

@jippie I am jealous.

@Kortuk I know! and I enjoy you being jealous at me.

hmm some people have interesting names ... look at who I've been answering for the past hour ...

oh event time @Kortuk

or did we miss it again?

Hello

morning

'evening!

it's 17:18 here in Europe.

western one at least.

it is always morning somewhere in the world

LOL Thanks once again for taking your time with my oh-so-strong-desire-to-understand-how-things-works.

I couldn't resist all the slight improvements.

In the while, I totally take apart a multimeter that fell apart mostly completely, but that's another story.

...

I spent the last hours watching this. It is fun as heck youtube.com/watch?v=gh1n_ELmpFI

I never heard the sentence 'heap of shit' so many times in 52 minutes

yeah he makes nice vids

Anyhow, I still heve some question mark floating above by head, so here I am in the hope to get (even) more clarity

foremost.

why constant current is varying so much between ranges?

even dropping while the range goes up, in a casa?

case.

The constant current changes per range in such a way that it is easy for the rest of the meter to display the correct value.

every range has a constant current. If you use the same current for several ranges, the voltage across your resistor will get too high (out of scale) or too low (too little resolution)

@Anal what instance are you referring to?

DT-830B unit.

DVM2000 as well.

For the DT, it's between the first and the second ranges.

For the other one it is between the 50 and the 500 ohms.

the dvm2000 has steps of roughly factor 10, just like the range of resistance has a factor 10

the dt-083b obviously uses the same current source for diode testing and for a good diode test you want about 1mA constant current.

I am starting to think (it's some time actually) that I am probably diving in something too hard for me to understand - yet.

and of course it is all about design desicions

yup!

some decisions are better for quality, some decisions are better for cost.

Let me sum this up. So to check if I got something.

What they internally do is try to get a stable current out of an unstable source - that is, the battery.

And that this voltage drop is, in short, related to that.

The details are above my level uf understanding up to now. :P

@Anal no the important thing is not the voltage that the ohm meter supplies, but the current. The constant current. That is actually what comes out of the two wires of your ohm meter.

yes:11120492

@Anal partially, yes. Also remember that you load your ohmmeter current source with the input impedance of your voltmeter. That was at around minute 6:00 of Dave's video ;o)

Yes. Thanks. My first meter was my tongue and I was only able to get a (quite rough indeed) measurement for that.

I mean, only for VOLTAGE.

@Anal yeah don't do that :-p

My book told me so. :)

hey @jippie - I've found an old TV-related IC, Motorola MC1391P - Says it is a TV horizontal processor. Now, I have no idea where it came from, I guess it came as an accidental substitute for a bunch of DIP op-amps I bought recently. So is there anything interesting I could ise the MC1391 for, do you think?

@Anal While testing the very small current a battery operated, low end multimeter produces, may be safe for tongue testing, it's a really bad habit to inculcate. Some day you'll try the same trick with something connected to the mains supply, even via a battery eliminator / wall-wart for instance, and you won't be here to chat with us any more.

I took about 7 second look at the datasheet. I think what it does is lock on the color carrier pilot and do something smart with that

@AnindoGhosh I think it perfectly doubles as a smoke generator :-p

I think it is pretty much useful when designing a PAL or SECAM or NTSC decoder or so

not entirely sure why it has a sawtooth input

@jippie Yeah well it seems to be something that might lend to creative fooling around with oscillators and stuff. I was looking for ideas. Hate to throw it away. I could sell it on eBay for $2 or something, I guess ;-) That's more than I paid for 10 LM358 op-amps, one of which seems to have been switched with this IC.

:)

@jippie Latest update: The local shop I buy electronic components from will happily exchange it for a couple of TLC5940 constant current PWM driver ICs, which I needed. That's not bad, since I have no use for the MC1391, I was hoping for some creative ideas from you before deciding to get rid of it.

not a bad deal I guess

@AnindoGhosh or they know the true value of the thing ;o)

Woah

@jippie Well, on eBay the MC1391 is $2 in singles, lowest price. The TLC5940 DIP is $1.50 in singles, lowest price. So it's a pretty close match - plus my friendly shopkeeper favors me a bit.

@Guy Woah?

Oh sorry, I was just testing out the chat

Just started here today

@Guy Welcome aboard. I hope you enjoy your stay. :-)

@Anindo Ghosh Actually, is there a room I could go to to ask about a computer problem I'm having?

@Guy You could try the SuperUser stackexchange and its chat room, I guess. State your problem, maybe some of the gurus here could help too (not me, probably)

Ok, I've been having this problem that just appeared where some webpages won't load

If I'm using GC, it will just load for about 5-10 mins, and then go to the "An error occurred, Google Chrome can't access the page"

On IE, it just loads indefinitely

check your choogle grome version is the latest one. Find a common denominator between the web pages that won't load.

@Guy I'm even a lesser guru than @AnindoGhosh when it comes to these things

@Guy OK, just so I understand: So this problem began recently, and these pages were loading OK on both browsers previously? Next question: Anything in common between these sites? As in, are they all related sites / same owner / same site, or are they diverse sites including some big-name sites?

I've looked for any similarities, but I can't seem to find one

All wikia sites don't work

(any site that starts www.wikia._____.com)

almost sounds like a DNS problem

or hosts file

But, various other sites don't seem to work either

@jippie I was just thinking that... Either that or spyware / malware.

you could run a command on the commandline nslookup www.wikia._____.com

Such as when I Google search for something usually around 2 of the sites don't work

@Guy What operating system are you on? Windows?

and see what it returns

My OS is Windows 7

@jippie What is the commandline?

@Guy what do you mean by that comment? instanteneously or continuously?

Sorry, I'm not extremely tech-savvy. I just know most of the basics

@Guy now that is the reason why I always say I don't know about computers

nothing personal BTW

saved by the bell, my dinner is ready :)

What does that mean?

@Guy Press Windows-R, type in CMD, press enter. Black box should open up, that's your command line.

Oh, that thing

I thought it was called the command prompt

@Guy Once you're in that window, type in nslookup www.whatever.is.not.loading.com

@Guy Same thing, various terms for it. Also called command console, or just console, by some.

Okay

So

@Guy So what result do you get from that command?

***** is where the name of my user is

@Guy However, the IP address you got also belongs to Wikia.com so it's not invalid.

@AnindoGhosh Hm, so what could be the problem?

@Guy Do you have a third browser? Also, do you have some spyware protection, such as SpyBot-S&D ?

@AnindoGhosh No third browser (i don't want to have to download Firefox, although I considered it). I have SUPERAntiSpyware

@Guy Well, in that case I guess your next stop is the SuperUser chat. :-)

@AnindoGhosh Okay, well thanks for the help =)

I also called my Internet provider and my previous Security program, Norton

@Guy Sorry couldn't be much use to you.

None of them could find anything as well

@AnindoGhosh That's okay, thatnks for yur time

*your

mind the new answers @guys can do with a couple flags.

@AnindoGhosh he's answering his own question

@DavidKessner I have ubuntu server running on my beagle bone black.

@jippie Who is answering which question?

oh the gibberish question

nobody understands that question but the person who wrote it

yet someone can answer it

I guess I was wrong on that account ;o)

dude

what does a yellow [active] mean behind a flag? In the list of flags I issued?