Electrical Engineering

Kortuk

12:06 AM

@Gilles That is probably not a great fit for ED. Sorry to say it.

@DanielGrillo I connected the dots later.

@DanielGrillo Hope all is going well for you.

Kortuk

1:37 AM

0

Q: Is USB car-charger with output 5.6v DC safe to use with battery-powered device designed for standard USB input

USB standard says voltage should be 5.0 +/- 0.25. I have a car charger that specifies its output as 5.6v DC. How safe it is to use this charger to charge battery of HTC phone, that comes with a 5.0v-output home-charger? Can this difference in voltage harm battery in any way or shorten its life?

Consumer electronics?

Kortuk

2:26 AM

@reemrevnivek yeah, i saw the feeds and assumed you guys were trying to change up the settings. glad you got it fixed.

markrages

3:38 AM

,

W5VO

hey mark, what's up?

Kortuk

5:05 AM

@markrages, how goes it?

@W5VO Sure, dont say hi to me.

W5VO

6:24 AM

@Kortuk I was here first :p

Kortuk

6:40 AM

@W5VO doubt that

But, hello @W5VO

@W5VO, you also said hi to mark and he was here second!

(third?)

markrages

hi there

anybody got a hp 16550 logic analyzer?

all asleep I see

hi @W5VO @Kortuk

I can babble... I got the LA off of ebay

hard disk error

replaced it with a 1G solid-state disk and copied system software

it appears to work. great for the bearded unix geek in me: ftp, NFS, X-window built-in

but the fan sounds like sitting in row 27 of a 737 airplane

Kortuk

@markrages I am not asleep, night shift at work for the next two weeks

markrages

hey

Im not alone

Kortuk

@markrages That sucks, Have you tried replacing the fan and adding a few more on the outside to improve air flow. If you still notice heat, add some cooling, maybe a peltier array to improve the efficiency of a loud fan?

I hate loud fans also @markrages, What are you doing up so late, or are you not US based?

markrages

6:56 AM

I'm US based

Kortuk

Then why up so late?

markrages

Some projects are just late night projects

Kortuk

(i was pretty sure you were US based, I think you wrote something once, or it is your style of speach)

markrages

Missouri

anyway, it's not overheating

it's just a loud fan

doesn't sound like bearing noise

Kortuk

yeah, replace it!

markrages

6:58 AM

just like a jet engine

Kortuk

hmmm

markrages

it's one of those 5" muffin fans

Kortuk

I have to say I never have to maintenance fans. Is there a way you can decrease the speed. That sounds like it is caused in general by the velocity.

markrages

the 16500b is a mainframe

so the fan is sized to keep it cool when you have it stuffed with cards

and then oversized, cause it's HP

Kortuk

Ahhh yes.

I read your nomination and laughed, I also still type chiphacker.com. I tried to get electropus brought through for the new site. IP issues I think caused them to not try.

markrages

7:01 AM

yes

I was active on chiphacker, then I became discouraged and gave the site up for a while

Kortuk

I had the same thing happen

There was a really good question that they bashed and admin deleted. I left for a bit

There were many many hobbyist there and they missunderstood what the user was asking.

Ahhh well, what discouraged you?

markrages

something similar

there were some know-it-all users dispensing wrong advice and getting upvoted

Kortuk

Yes, that took a major part in it also for me

I was not a know it all, i hope, but I knew enough to know when something was seriously wrong. You are by far my technical superior though. Who knows how often I gave bad advice.

markrages

well, it's not the technical superiority

its the humility to shut up when you don't know the answer

Kortuk

We only have a couple users here whom try to answer everything.

markrages

7:05 AM

the "new" site is a lot better

Kortuk

I think out of the mod statistics I looked at most people running for mod get at least 3 votes per post.

Glad to hear that @markrages

I hope I am not being to frustrating to you about the shopping advice.

markrages

It's a little frustrating. I believe electronics design is fundamentally different from most of the SO sites

I am active in other forums, piclist, mspgcc etc

Kortuk

I do hope my point that good shopping questions will never be removed is clear also. When someone just wants to know where they can get a better deal on a part is inherently bad. It means nothing possibly a week later when demand or supply changes.

markrages

and I am often helped by shopping advice offered to others

even that kind of advice is useful to me

Kortuk

@markrages I think quesitons where someones good answer is learning about a technology they did not know already existed as a SoC is good. Just asking, I already can do X for Y dollars, how much cheaper can I do it? seems bad bad to me

markrages

7:09 AM

because things don't change that fast, and learning where to find certain classes of parts is helpful

Kortuk

@markrages For a week? I mean, yes, it can be useful to know that, but the question is invalid in a week and the site is targeted at making a bank of useful knowledge.

@markrages Prices can change that fast imho.

again, you have more experience then I do.

markrages

I design for the consumer market, and if you can redesign for a dollar cheaper, that's a huge engineering victory

Kortuk

Even a year though. I get SO help from old questions, never had one come up in google that was any newer then 4 years ago. I wish the same was true for Electronics design.

@markrages I understand that price is inherently important, especially in consumer.

markrages

the price might change, but when someone asks, "where's a cheap place to find X"

Miss

hi all

markrages

7:11 AM

the replies are a goldmine to someone else trying to buy X (or Y, where Y is like X)

Kortuk

@markrages But asking where to get a part cheaper is inherently the easiest question, this would result in highest rep users just knowing how to look up information.

@Miss hello

markrages

even if the price has changed, the same distributors will be in business selling the same kinds of part

for the most part

Miss

i was to know steady- state and transient response...

markrages

I think lazy shopping questions are bad

Miss

let me post figure

markrages

7:12 AM

like most lazy questions

Kortuk

@markrages I think one good CW question to discuss suppliers. just one question that has a list of

markrages

hi @Miss

Miss

hi all

Kortuk

@markrages A good shopping question is inherantly going to fit. The issue is probably our differing definition of good.

@markrages, more then just giving a price quote.

@markrages, or finding a supplier that has gotten a higher failure rate batch and will not tell you

Miss

how should i post my example here

Kortuk

7:14 AM

@Miss we do question on the main site, this is more for off topic and site administration discussion.

Miss

ah..

Kortuk

@Miss You can, but if you have a solid technical question that is what the site is for.

markrages

post to the main site and we'll have a look

Kortuk

@Miss we occasionally handle some basic technical discussion, but if we teach you on the site all can help and learn from it.

Miss

idea !! hold on...:)

Kortuk

7:17 AM

if it helps @Miss

Steady state (electronics)

In electronics, steady state is an equilibrium condition of a circuit or network that occurs as the effects of transients are no longer important. Steady state determination is an important topic, because many design specifications of electronic systems are given in terms of the steady-state characteristics. Periodic steady-state solution is also a prerequisite for small signal dynamic modeling. Steady-state analysis is therefore an indispensable component of the design process. Calculation methods Steady state calculation methods can be sorted into time-domain algorithms (time domain se...

Transient response

In electrical engineering and mechanical engineering, a transient response or natural response is the response of a system to a change from equilibrium. Specifically, transient response in mechanical engineering is the portion of the response that approaches zero after a sufficiently long time (i.e., as t approaches infinity). (Contrast with steady-state response) In Electrical engineering a simple example would be the output of a 5 volt DC power supply when it is turned on: the transient response is from the time the switch is flipped until the output reaches a steady 5 volts. At this ...

Miss

i want to psot an example and then figure

how should i psot here?

i am studying signal processing..

Kortuk

there is a button available.

when posting to link the image, it will upload.

Miss

and if i have a mathematical eq then ...

how should i post it here.

i try to copy and past here but useless

markrages

do you know TeX?

er, LaTeX?

Miss

nops

yes its an figure

now please tell me how to post an eq

ok yes

its an example

now i do't understand the figure according to this example

@kortuk can you please see & guide me..

i studied this link for understanding the steady-state & transient response..

but i did not understand yet when i saw that figure for the above given example..

markrages

7:30 AM

I suggest you collect this into a question on the main electronics.stackexchange site

also, what don't you understand?

Miss

i did not understand figure for steady-state response...

markrages

do you understand why the FIR filter only has five samples memory?

do you understand that if you pass a sinusoid into a linear system, you get a sinusoid of equal frequency out the other side?

Miss

yes i understand the second point

markrages

so the FIR filter is a linear system

Miss

yes mean LTI ...

markrages

7:33 AM

right

Miss

well i do't know your first point...

markrages

what does FIR mean?

Miss

finate impulse response...

sorry for spelling mistakes ..

finite impulse response

markrages

so how long is the impulse response for [1, -2, 4, -2, 1] ?

Miss

ths FIR is order of 5

and its length is 0~4

am i right?

markrages

7:36 AM

yes

Miss

ah .. ok

markrages

so the output of the filter isn't affected by the 6th previous sample

Miss

but is it necassary that order must be 5

yes right

markrages

no, I'm just using your example

Miss

ah ok ok

markrages

7:37 AM

the filter "remembers" the last 4 samples (+ the current one)

if you actually write the implementation

you would find yourself reserving memory for those four samples

Miss

hold on.. i am studying this for signal processing...

since this subject comes in electronices so i posted here ...

markrages

um

ok

Miss

thanks for understanding...

markrages

the real world doesn't divide neatly into categories

like electronics vs. computer science vs. physics

Miss

hm..

yes right

markrages

7:40 AM

so the more ways you can approach this, the better you

can understand

Miss

yes i agree...

markrages

so in relation to the figure

at the start of the input

Miss

yes

markrages

you have a discontinuity in the sine wave

Kortuk

@Miss Sorry, I am at work, was afk.

Miss

7:41 AM

ahh..@kortuk..ok ok

but please make it clear for steady-state & transient response

markrages

as this goes through the filter, you have a step response superimposed on the siusouidal output

Miss

ahh yes

markrages

once it's worked its way through, the filter has forgotten about the discontinuity

and you get a sinusoid out

is that helpful?

Miss

you mean disconitnuty is removed in output signal

is it/

?

markrages

it's filtered there

consider the step response of the filter

I assume you've done the convolution by hand

to se why the transient response is what it is

I was trying to give an intuitive handle to what you see

Miss

7:45 AM

hmm ..

well i understand this that there is actaully noise in the signal.. by aplying the filter we remove the discontinious from the signal...

thats it...

means high pass filter applied to low pass filterd signals...

markrages

not quite

Kortuk

I do not think that is what he means

well, he beat me to it

Miss

hmm..

Kortuk

the wiki article uses turning on your power supply.

markrages

so there is the region between the sinusoid applied

Kortuk

7:49 AM

While the power still ripples as it turns on and attempts to regulate with the load you are dealing with transients. The continuous 5V you get from there on out are examples of a steady state signal.

markrages

and the sinusoid coming out

that is the filter digesting that step

when it's done digesting it

it poops it out

and then clean sinusoid form then on

the intestine is four samples long

Kortuk

haha, i like it

markrages

heh

I'm off to bed

@Miss, post on the main site

and get more perspectives

Kortuk

@markrages, have a nice night mate

markrages

gnite all

Miss

7:53 AM

wait please

Kortuk

@miss, helping you in chat is like private tutoring, we are not private tutors, we prefer help on the site where the general public can learn. It is more like directed lecturing. Most users enjoy teaching, but like the reward of rep and helping a greater audience.

Miss

8:09 AM

ah/.. i just have to know steady-state response also transient

but after talking with @markang... i got some understanding .. but i am not sure...

so now i would like to expplain that figure that i understood...

actaully transient region where the noise is removed...

in my figure, transient region is 0<n<3 ...presentated as shaded in output...

thats actaully remove...

and you can see.. as output presrved input signal n>= 4 , thats a steady-state region... and finally we removed the noise from the signal

so that mean high pass filter applied to signal..

thats it

Kortuk

8:32 AM

@miss, careful with your use of the word noise. I am not sure you are at a point where you understand what is meant by noise. You are still at building blocks.

A transient is not noise, really. It is an expected output of your system. It may be detected as noise if the user or designer does not know why it is there.

Miss

9:23 AM

hmm..

@kortik: noise means disturbance...

Kellenjb

12:31 PM

Only 23 non-mods are capable of voting to close questions right now. i really think SE needs to rethink how they do their rep privileges for new sites

reemrevnivek

1:45 PM

@Kellenjb I think that 23 active users interested in bootstrapping the sites can handle the task for the most part, but other privileges:

Voting to delete answers with score of -1 or lower
Voting to delete questions immediately after they are closed (even if they are new)
Editing all tag wikis on the site

protect questions

cast delete and undelete votes on questions
view deleted posts
see spam and offensive flags on posts
have access to moderator tools

(See electronics.stackexchange.com/privileges/moderator-tools)

are only available to Joby and Leon.

Kellenjb

yeah, those are issues also... but even though there are 23 users high enough for vote to close, i dont believe they are all active

such as Jason S

and there are many others that may come around the site, but i have never seen them on a vote to close

my latte is not so yummy this morning. i think i got the girl who always manages to mange the drinks taste bad

reemrevnivek

...and Leon hasn't shown much interest in moderating. He has a lot of edits, because he always posts the first answer to most questions, and then updates it later, but he hasn't ever posted to Meta (apparent from the site) or even been to Meta or Chat (just based on my recollection)

Kellenjb

he does vote to close though, which is helpful

reemrevnivek

@Kellenjb - true.

Kellenjb

a quick look makes it look like there are about 10 users who are active enough and can vote to close

reemrevnivek

1:59 PM

@Kellenjb - What do you think the rep requirement should be?

Kellenjb

well... the more i think about it the less worried i am

reemrevnivek

What users are active, involved, and trusted enough to be given the privileges currently restricted to 5k, 10k, 15k, and 20k users?

Also, I think the message "We've adjusted rep requirements down, you now have new privileges" would be well-received, but "Rep requirements are going up" would be protested.

Kellenjb

i guess what i look at more is that we were a pretty strong site when we graduated, and i know most are not that strong just because they didnt have a seed like chiphacker to help out the over all rep of users

reemrevnivek

I was going to post a proposal to MSO, but I didn't have a quick answer to those two questions so I decided not to.

Kellenjb

i look at users like dean, he seems more then qualified to vote to close, but is only half way to the rep required

reemrevnivek

2:07 PM

@Kellenjb Good point. It's an advantage, but it's not as big as I would have guessed.

stackexchange.com/leagues

Click through some of the new sites - many have 5-10 users with >5k

I think part of the problem is that the best users aren't those that post lots of answers.

Kellenjb

flag weight could be interesting to look at, but i can seen some issues with it

@reemrevnivek you and your small 235 flag weight ;-)

reemrevnivek

Yeah, I'm working on it. I try to handle simple problems myself, rather than just send it off to the mods.

Kellenjb

i send stuff like answers that should be comments (because i know mods can convert it with 1 click when they have a flag) and things that are getting out of control with anger

for people who are looking for jobs, interesting about large companies and how many they are hiring: money.cnn.com/galleries/2011/fortune/1105/…

reemrevnivek

6:07 PM

2 days left on the election.

@DanielGrillo - Can you tell how many votes have been cast?

Daniel Grillo

@reemrevnivek 393 voters are eligible for this election, 94 visited the election, and 53 voted.

reemrevnivek

Kortuk said here that only 47 votes had been cast as of Saturday. So, we've had 6 more votes!

I wonder why so many people visited but did not vote. Perhaps our blurbs were too long?

Daniel Grillo

@reemrevnivek Maybe they're letting to the last day.

reemrevnivek

6:22 PM

I'm also surprised that there are only 393 users with >150 rep (eligible to vote).
Checking the user pages reveals that there are (at 36 users/page) :
393=11 pages of eligible users

393=11 pages of users with 102 < rep < 150

1008=28 pages of users with 101 rep (Our biggest group!)

468=13 pages of users with 2 < rep < 100

648=19 pages of users with 1 rep.

I suppose that I would have guessed that roughly 50% of our users are non-participatory, but it feels surprising at first glance.

reemrevnivek

8:48 PM

Hey, got a new badge:

electronics.stackexchange.com/badges/69/vox-populi

(Bronze) Vox Populi: Used the maximum 40 votes in a day.

Apparently, it's a brand new badge. Wikipedia says that Vox Populi means "Voice of the people".

Here's the Meta.SO FAQ question:

5

Q: What's the difference between Suffrage and Vox populi badge

Suffrage - Used 30 votes in a day. Vox populi - Used the maximum 40 votes in a day. 40 is now a new day limit for casting votes?

discussion badges

...and here's the blog post:

Stack Overflow Blog: Vote For This Question or The Kitten Gets It

Posted by Jeff Atwood on May 6th, 2011

When the wordpress.stackexchange.com community asked Why are questions not being voted on …

I have noticed a trend that questions (even good ones) that have multiple answers are not being voted on.

Out of our 5,550 questions only 41% have at least 1 vote which leaves around 3,000 with 0 votes and a few hundred with negative votes.

I had a strong sense of déjà vu all over again.

One of the longest running concerns in Stack Overflow and Stack Exchange history is Why aren’t people voting for questions? a question originally posed on Stack Overflow on August 5, 2008 — long, long before we used UserVoice for this sort of thing. At that point, meta.stackoverflow wasn’t even a glint in anyone’s eye, much less Area 51 or the WordPress Stack Exchange. …

Gah. Posting links like that always gets me the "You can retry this action again in 1/2 seconds...

That badge wasn't in my list of "wanted" badges, which currently includes:
Bronze: Tag Editor
Silver: Deputy, Enthusiast, Pundit, Taxonomist
Gold: Copy Editor, Electorate, Fanatic

I think those are badges I can be proud to have. Some of the others (more to the point, some of the others which I don't have right now) seem to be more selfish in nature.

Also, WRT the Tag Editor badge, who handles the tag wiki edits and approvals? I'd be editing them like crazy, but I don't have the proper privileges and I don't want to be a burden on the mods that they don't need.

Kellenjb

9:18 PM

@reemrevnivek They must have upped the limit because i thought this badge was for maxing out your votes in a day:

electronics.stackexchange.com/badges/58/suffrage

oh, just read more down

reemrevnivek

Yup, they did. Makes the Electorate badge much easier to get. In fact, it almost forces it, assuming you max out your votes frequently...

Kellenjb

/me gets to voting :-P

Kellenjb

9:50 PM

3

Q: Inserting a Simulated GPS Entity in Motor Base - Microsoft Robotics Developer Studio

I'm very new to MRDS and I'm trying to simulate a robot driving a car. I have used the Motor Base with Drive in the EntityUI manifest and would like to insert a GPS sensor to it to get its coordinates and maneuver accordingly. So I inserted the GPS sensor in the Visual Simulation Environment and...

sensor robotics gps microsoft mrds

It's GPS, but specific to a robotics question, wonder if it should be on the site or not

reemrevnivek

On a first glance, I would have said that it's only tagged robotics because the electronics involved are on a robotics platform.
Adding a GPS sensor to a motor base? Sounds like electronics to me! They're doing electronics design, not robotics design, so I say that it can stay on the Robotics vs. Electronics grounds.

Kellenjb

0

Q: Robotics questions that are electronics based

So, as I am sure everyone in Meta knows, we are no longer the home for robotics, but where does our scope end? Specifically this question: Inserting a Simulated GPS Entity in Motor Base - Microsoft Robotics Developer Studio It is a GPS question, but specific to software for robotics. Opinions?

discussion

reemrevnivek

However, after further reading, they're using MRDS. I don't see any indication that they intend to use any electronics to make a physical realization of this system at any time. Therefore, I'd say it's not on topic.

OK, fine, off to post my reply as a Meta answer...

:)

Kellenjb

i figured others might want to chime in and would be good for us to have something to reference in the future.

and I just learned we have a microsoft tag

electronics.stackexchange.com/questions/tagged/…

I feel like someone should be able to answer this question:

3

Q: Lightning/surge protection for a Arduino monitored thermistor circuit

I am considering whether to replace the commercial differential temperature controller on my solar water heater with a Arduino based controller of my own design. I know just enough to be dangerous about such things. First question: will the classic 5V/10Kohm thermistor voltage splitter circuit ...

arduino solar-cell protection thermistor

reemrevnivek

@Kellenjb Interesting. All Microsoft Robotics questions. Perhaps this should be changed to microsoft-robotics?

This would eliminate a number of robotics questions along with the microsoft tag.

@Kellenjb I think it should be (/ should have been) split up. The first question is dangerous and difficult to answer, the second question is easy-peasy beginner stuff.

@Kellenjb Answered.

reemrevnivek

10:29 PM

Well, I'm headed home. See y'all tomorrow.

Kortuk

11:44 PM

@reemrevnivek Think about the number of users whom do not feel well informed enough to vote.

I still do not vote in IEEE elections, but I can. I just do not know enough about the material.

@reemrevnivek Sounds like a great choice

@DanielGrillo It was only 51 voted yesterday. (cc: @reemrevnivek)

Transcript for

Electrical Engineering