Electrical Engineering

coding_corgi

00:36

@anorton awesome!

anorton

01:12

@angelatlarge sorry... I stepped away. :)

angelatlarge

@anorton No problem, of course. Have you ever used chat on Stack Overflow?

anorton

Yes, actually. I stepped in the Rebol room to chat with their robot, but not for much else

why?

angelatlarge

@anorton I just keep asking off-topic questions here, but I haven't had much luck with SO chat.

anorton

haha. Yeah. I stepped in the C++ Lounge once, but it didn't seem to be that helpful-looking...

But, of course, that may just be because I'm not a regular...

angelatlarge

@anorton They also aren't as active as the people here it seems...

anorton

01:19

true.

coding_corgi

01:49

Yo yo yo!

@angelatlarge Yes, I have tried many chat rooms, this is the best GeeK one (programming, EE, etc.) and most popular and friendly chat room I could find...

(Sorry, I also forgot that people here are also funny) :]

Is anyone else here?

angelatlarge

@coding_corgi That's been my experience too

coding_corgi

@angelatlarge Ok, you're here (glad you settled down...) @anorton Are you here still?

anorton

@coding_corgi I'm here, but I'm supposed to get some work done, so I can't talk much...

coding_corgi

@anorton Get your work done then, join the party when your done! :]

Feeds

W5VO has added W5VO to the list of this room's owners.

anorton

01:56

woah...

<sarcasm>I'm sensing a take-over!</sarcasm>

@W5VO what's up?

W5VO

@anorton No takeover

anorton

Sorry... forgot my sarcasm tags. :)

coding_corgi

@W5VO IS TAKING OVER!!! EVERYONE RUN!!!!!!!!!!!!! RUN FROM KIM JONG ... (North Korean Dictator)

@anorton RUN!!!

W5VO

I seize this room in the name of The Moderators!!

4

anorton

@coding_corgi I may just run out of earshot of you... that way, I don't hear any shouting. :D

coding_corgi

01:58

@W5VO That was scary, just saying...

@anorton Ok, I am running as fast as my geek swivel chair legs can take me! (JK Love running!)

@W5VO Nooo0o0o0oOOOoooo000!!!!!!! BoooooooooooO!

anorton

@coding_corgi In the immortal words of yourself, SHUT UP! ;-)

coding_corgi

@W5VO Really? I saw my browser tabs going (1) then (2) then etc.. I looked, and I saw something very scary...

@anorton Only if I get a start! ;] JK JK JK!

anorton

@W5VO All joking aside, I'm curious as to why this room needed fewer owners.

of course, if those other owners were just added as a joke or something, the answer is obvious. :)

coding_corgi

@anorton @W5VO Yes, me too, WHY!?!?!

anorton

@coding_corgi calm down... :)

I trust him--I don't think it's a takeover.

;)

coding_corgi

02:03

@anorton Yes, I like to be on the side with more power too, :]

@anorton Sorry, just had gummy bears! All hyped up with sugar! JK JK JK!

anorton

@coding_corgi New rule: No gummy bears for coding_corgi.

2

coding_corgi

@anorton Just like being dramatic.

anorton

(Everyone star my above line) :D

coding_corgi

@anorton Why not? ;]

@anorton Definitely NOT! What did I just do!?

angelatlarge

@W5VO Huh. The room owners were definitely changed. My sock puppet master (a.k.a. The Very Liberal Dictator) and his minions are no longer the owners, it looks like. And some person named tyblu is.

vvavepacket

02:15

anyone familiar with LUTs? (logic cells)

coding_corgi

@angelatlarge tyblu ? Hmmm.... I don't like this new leadership... @jippie Please read the chat messages above if you are wondering why you aren't the room owner, feel sorry for you! Naaahh, whatev...

angelatlarge

@vvavepacket Not me. Sorry

@CamilStaps No more "powers". Wah-wah-wah

coding_corgi

@angelatlarge Hee hee hee hee...

@angelatlarge Now it's all moderators and 'tyblu'

anorton

and Kevin Vermeer

angelatlarge

@anorton Kevin Vermeer used to be a mod here.

coding_corgi

02:23

@anorton But he's a moderator, look closely....

@angelatlarge But it still says he is in his profile

angelatlarge

@coding_corgi That's a fake diamond :)

anorton

He isn't now...

electronics.stackexchange.com/users?tab=moderators

coding_corgi

@angelatlarge Really? I am going to add a fake diamond to my name....

angelatlarge

@coding_corgi It'd be funny if you could add it to the name. Only on your about page is possible, I suspect.

anorton

I think it actually would be feasible.

coding_corgi

02:25

@anorton This will be my new about page: ♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦

anorton

If it wasn't for the fact that name-changes must wait for nearly a month to re-attempt, I'd try it... :)

coding_corgi

@anorton me too, but...

angelatlarge

Anyone here know some computational geometry? I am trying to figure out how to find a point (in a unit square, say) that is maximally distant from a set of points in that same unit square. Any pointers for where to look, of what this is even called?

anorton

@angelatlarge Just tried it. No can do. :(

(not the computational thing, but other)

coding_corgi

@anorton :[

angelatlarge

02:28

@anorton Yeah, I saw what you were replying to

@anorton It'd be very surprising if you could.

anorton

Yes, it would be...

coding_corgi

@angelatlarge Yes it would be, maybe this could my name cool: ŒŒ§«¬¬¬ etc.

anorton

@angelatlarge How do define "maximally distant" from a set? The sum of all the distances, or the minimum distance to any point in that set?

angelatlarge

@anorton Ah! Good.. ahem.. point! I need a point maximally distant from every the point in the set.

@anorton Sorry, to clarify...

@anorton I need a point such that the minimum distance to any point in the set is maximized.

coding_corgi

Can you guys believe there is a dagger ascii char?! †

anorton

02:36

@angelatlarge Do you care about situations in which multiple solutions are possible?

angelatlarge

@anorton Whatever is easiest.

@anorton This seems useful, though not exactly right on

0

Q: Find a point that maximizes total distance from a set of points within a bounded area

Given a set of points p, I would like to find a point within the space b that bounds the region of p that is as far distant as possible from all points within p. This is in regards to implementing neighbor avoidance in a flocking simulation as per Craig Reynolds' Boids - if this isn't the best w...

W5VO

02:51

@coding_corgi If you don't know who @tyblu is, then you haven't been around long enough :)

angelatlarge

@anorton I guess one solution (as stated in the answers) would be to generate a voronoi and iterate the edges, just checking looking for the furthest point from among all points that define the voronoi edges. Trouble (for now) is that something like this is a 2d voronoi solution, whereas my space is 3d, so I might have to write my own voronoi implementation (ugh! really?) where a lot of the work can be saved, I presume.

W5VO

also, how much of a takeover is it if I'm in charge enough to make myself an owner?

EwokNightmares

Is anyone here good with electromagnetism theory?

coding_corgi

@W5VO I have seen him, he's the owner of this room and not even in the room! Maybe we should have elections on who should be room owner of this chat, since it is like the 'mascot' of SE.EE

@W5VO A big one

angelatlarge

@W5VO I guess that includes me too. I don't know who tyblu is. Is there an inteval named after him/her?

W5VO

02:53

where's the MOD ABUSE comments?

coding_corgi

@angelatlarge It's seems to be a him, because of his profile pic

@W5VO ?

W5VO

lol

angelatlarge

@coding_corgi If profile pics are to be believed, then you do not have an opposable thumb and like digging up the yard.

coding_corgi

@angelatlarge Ok, sorry, but I mean really....

angelatlarge

@coding_corgi :)

@coding_corgi Funny "rule" when you think about it though. Picture of a human implies that it is a picture of the account owner. Picture of a non-human -> no implications whatsoever.

coding_corgi

03:00

@angelatlarge It took me time and care to photoshop a Pembroke Welsh Corgi jumping

angelatlarge

@coding_corgi Ah. That's what a corgi is.

David Kessner

Hi all.

coding_corgi

@angelatlarge No stupid (sorry, i like to call people bad names), There is a Welsh Corgi, Pembroke Welsh Corgi, and something else I think,

@DavidKessner Yo!

David Kessner

I designed a new chip. It's called the LM666. Here's a link to the design files: thingiverse.com/thing:92778

coding_corgi

@DavidKessner AWESOME!

David Kessner

03:04

It was a devil of a time getting it to work properly.

coding_corgi

@DavidKessner A little fat though

David Kessner

@coding_corgi I'm working with Babylonian technology here.

angelatlarge

@DavidKessner Stone tablets?

David Kessner

@angelatlarge For the data"sheets", yes.

The pin pitch is 3 cubits.

angelatlarge

@DavidKessner :)

@DavidKessner Cute!

The Photon

03:41

I, for one, welcome our new nixie tube overlords.

David Kessner

@ThePhoton I thought about doing a vacuum tube of some sort, but it just isn't the same without the glass. And I can't 3-D print glass.

The Photon

@DavidKessner At least you've got multiple colors.

Nevermind, I just saw you painted it.

David Kessner

@ThePhoton I can sort-of print in several colors. Basically, one color at a time but I can switch colors part-way into a print

angelatlarge

@ThePhoton Smart idea

angelatlarge

04:25

@jippie BTW, thank you so much for pointing me to proprietary drivers. Working much better (so far!)

vvavepacket

@DavidKessner nice chip number!!

Anindo Ghosh

04:42

@DavidKessner So what format does your 3D printer prefer? I could send you an inventor or 3DS or 3dsMAX file for a PC817 gullwing (SMD with DIP pitch) optocoupler, that I made.

angelatlarge

05:44

@AnindoGhosh Huh. Did you somehow remain in control of this room? You are still italic.

@AnindoGhosh ...and "hello"!

jippie

06:00

@angelatlarge welcome

good morning

angelatlarge

@jippie Yeah, super easy, super good, super thank you. And, like many good answers made me feel like a doofus in the end :)

@jippie Morning. Your "disciple" is starting to go a little nuts, BTW.

@jippie Perhaps it is the anticipation of your "retirement."

jippie

@angelatlarge you mean the muted one?

angelatlarge

@jippie Yes. Did you actually moot him?

@AnindoGhosh Please not that the above mute/moot change was intentional. I almost know the difference between the two, outside of the fact that "moot" is a strange, strange word.

jippie

You've earned the "arduino" badge. See your profile. Earned 100 upvotes for at least 20 answers in the arduino tag.

:o)

angelatlarge

@jippie He reminds me of Tony minus the age and (scattered) knowledge.

user61389

06:06

@angelatlarge :(

angelatlarge

@CamilStaps I am wrong. You too are still italic

user61389

Morning

user61389

@angelatlarge not for me, and I don't have powers

angelatlarge

@CamilStaps You I can't find you, @jippie, or @AnindoGhosh in the list of room owners.

user61389

@angelatlarge try a refresh :)

angelatlarge

06:07

jippie

@angelatlarge end of subject for me.

angelatlarge

@jippie Was I being too mean?

jippie

hey all italics are gone :|

user61389

@angelatlarge tried a refresh?

angelatlarge

@CamilStaps No. Too lazy.

@CamilStaps If it will make you happy...

user61389

06:08

:) neh, the longer I have the powers for you...

angelatlarge

@CamilStaps yup, gone

user61389

Oh :(

user61389

What's wrong with me?

angelatlarge

4 hours ago, by W5VO

I seize this room in the name of The Moderators!!

jippie

@angelatlarge m

user61389

06:09

@angelatlarge oh, yes, thanks for reminding me :)

angelatlarge

Actually, our benevolent overlords (a.k.a. @AnindoGhosh) did a good job of cleaning out stooopid message stars on daily basis. I fear that's all gone, and all that excrement will be nailed to the wall for all eternity.

user61389

Yes, they did. Do we know why? Did I do something wrong?

angelatlarge

@CamilStaps Yes they did = "They did clean out daily"? Do we know why = "Do we know why @W5VO took over"?

@jippie m?

user61389

@angelatlarge both true :)

angelatlarge

@CamilStaps Well, I guess that's probably how it is supposed to work.

user61389

06:13

@angelatlarge hm, okay

abdullah kahraman

Hi

angelatlarge

@CamilStaps @W5VO didn't answer me about it, but then the mooted one was... making his presence felt.

user61389

Ah, it isn't important, I just can't brag anymore

user61389

@angelatlarge yes, let me moote him tu - I don't understand him

angelatlarge

@abdullahkahraman Hello!

user61389

06:14

@abdullahkahraman morning!

jippie

@CamilStaps looks bad on your CV, having extra priviliges revoked.

angelatlarge

@jippie :)

user61389

@jippie I just have to become moderator, then I can delete all these messages :)

Anindo Ghosh

I would assume crap message unpinning now becomes a key responsibility area for the mods. All is good.

jippie

@AnindoGhosh oh I thought it was @kortuk or @W5VO who were unpinning my messages, because @AnindoGhosh or @CamilStaps wouldn't do that (get personal), would they?

user61389

06:22

@jippie not personal, I only removed a few when the muted one starred like 10 after each other

angelatlarge

@AnindoGhosh The moderators are not as omnipresent as the benevolent overlord

@AnindoGhosh And they (unlike the benevolent overlord) have enough on their plate: weddings, tornados, etc. The benevolent overlord, on the other hand, loves to smile upon his faithful subjects.

Anindo Ghosh

06:40

@jippie No, I don't recall unpinning any of your messages. Just some "OK" type one-word ones, and datasheet and code dump messages.

@angelatlarge Really now!

jippie

@AnindoGhosh hmm I shoud remove the - sign from @CamilStaps' name and move it to yours then.

user61389

@jippie what other signs does my name have in your black book?

Anindo Ghosh

@jippie Almost all of the ones I unpinned were either Corgi's work or hhh's - I assume they pin messages to remind them what they were reading - but the starred messages are of no interest to anyone else.

abdullah kahraman

►

@DavidKessner Would love this, lol

angelatlarge

@AnindoGhosh When you say "pin" do you mean "star"? Or are there moar powers that I am missing out on?

user61389

07:03

@angelatlarge you can also pin messages to the top of the star list, and unpin them, but @AnindoGhosh means unstar

Anindo Ghosh

@angelatlarge yup un-star

jippie

@abdullahkahraman So I get a Function + B to enable good sound? Why would I have disabled that in the first place?

abdullah kahraman

@jippie hahaha! Good point!

Anindo Ghosh

Why is nobody touching this question? It's just one BJT as a switch, measly 30 mA current needed... or am I missing something?

2

Q: Switching 12V with an active low 5V signal

I’m trying to switch 12V (max 30mA) with a signal from a MCU that I’d prefer to be active low (so the output voltage is 12V when the control signal is 0V, and 0V when the control signal is 5V). Since I have plenty of bipolar transistors at hand, I’m looking for a solution using bipolar transisto...

switches bjt 12v 5v

abdullah kahraman

07:19

@AnindoGhosh OK, I will write up an answer.

Anindo Ghosh

@abdullahkahraman First study the problem, there may be some catch I'm not noticing.

abdullah kahraman

@AnindoGhosh I think you didn't miss anything.

Anindo Ghosh

@abdullahkahraman And I simply cannot take time out for writing an answer today - I have a paper to write, I've only done the abstract so far. :-(

abdullah kahraman

@AnindoGhosh Oh, good luck with that

Anindo Ghosh

@jippie are you here?

abdullah kahraman

07:21

@AnindoGhosh shhh, I am going to write the answer! He has lots of rep!

Anindo Ghosh

@abdullahkahraman Scientific journal submission, not exam type paper.

abdullah kahraman

@AnindoGhosh Yeah, why did you think that all I know about papers are exams lol

Anindo Ghosh

@abdullahkahraman Yeah, I just needed to ask him something about the Joule formula he mentioned earlier.

@abdullahkahraman Well, you did say "good luck"

abdullah kahraman

@AnindoGhosh We have a saying in Turkish; "Kolay gelsin".

Google translates it as "Take it easy".

It means, let this thing that you are going to do be easy for you.

@AnindoGhosh So, I meant "kolay gelsin" by "good luck" :)

Anindo Ghosh

@abdullahkahraman got it :-)

thanks

abdullah kahraman

07:24

lol

Anindo Ghosh

07:48

Oh, I hate math!

Hey @abdullahkahraman are you here?

abdullah kahraman

@AnindoGhosh Yeah

Anindo Ghosh

@abdullahkahraman OK, I have what should be a simple math calculation, but it's confusing me. Care to help with it?

abdullah kahraman

@AnindoGhosh Sure, with pleasure, if I can.

Anindo Ghosh

@abdullahkahraman I'm sure you can. It's so ridiculously basic, I'm getting exasperated at myself, which is confusing me more.

abdullah kahraman

@AnindoGhosh And you are making me look up words again

angelatlarge

07:51

@CamilStaps When you say "you" you don't really mean me, do you?

user61389

@angelatlarge no ;) only the room owners

angelatlarge

@CamilStaps i.e. noone here.

user61389

@angelatlarge nope

Anindo Ghosh

@abdullahkahraman So here's the background. I need to calculate a suitable capacitance, such that if it is charged to 5 volts, then discharged via a resistor and LED, the LED will have 10 mA (when cap is fully charged) to 5 mA (when cap is at 3 Volts). How much capacitance value do I need?

angelatlarge

@CamilStaps Sad. Some of those "shut up" messages sorely need some unpinning/unstarring.

abdullah kahraman

07:52

@AnindoGhosh Oh, let me visit Wikipedia first

user61389

@angelatlarge get a smaller screen :) on my laptop, I don't even see them

Anindo Ghosh

@angelatlarge I agree. They are too childish to be the highlights of this chatroom for a newcomer to see.

angelatlarge

@AnindoGhosh Yeah. Though an honest representation of what the room is now like, at times :(

Anindo Ghosh

@abdullahkahraman Oh, and take LED Vf to be 3 Volts.

user61389

@angelatlarge it will go away

abdullah kahraman

07:54

@AnindoGhosh That is not possible, if the resistor is not somewhere about 1mohms?

Anindo Ghosh

@angelatlarge In general, I've found that immaturity cures itself with time and gentle mentoring. Don't be so concerned about it.

angelatlarge

@CamilStaps I guess I could also put a fist through my LCD, or use whiteout...

Anindo Ghosh

@abdullahkahraman Hmm right, let's take the discharge stop point to be 4 Volts. Sorry, obvious logical fallacy on my part.

user61389

@angelatlarge yes, that's the generally accepted method

angelatlarge

@AnindoGhosh What is this "gentle" word you speak of? I need to go look that up. Maybe @abdullahkahraman knows that that means.

abdullah kahraman

07:55

@AnindoGhosh Do you have a specific time that you want to go to 4V from 5V ?

Anindo Ghosh

@angelatlarge I wonder if, when you mute somebody, their pinned messages get muted as well.

abdullah kahraman

@angelatlarge I am very bad at vocabulary

Anindo Ghosh

@abdullahkahraman Yes of course. Looks like I'm just not providing the full problem statement. 0.1 seconds.

angelatlarge

@jippie What arduino badge? I don't see anything new...

user61389

@angelatlarge it's tag-specific

user61389

07:57

electronics.stackexchange.com/badges?tab=tags

Anindo Ghosh

@abdullahkahraman If it was just a resistor, calculation would be a standard RC time constant calculation. Since there's the forward voltage of the LED involved, that's adding too many variables for my aging mind to grasp.

@angelatlarge Look at the badges I have. See the LED and Arduino ones?

Connor Wolf

it's still a standard RC time thing, the only difference is that there is a non-linearity in the R from the LED

angelatlarge

@AnindoGhosh Yes. I don't have anything like that.

Anindo Ghosh

@angelatlarge You will, I'm sure.

abdullah kahraman

@ConnorWolf Yeah

Anindo Ghosh

08:00

@ConnorWolf Exactly. While I understand that conceptually, when I try writing equations, my mind balks. Stems from some childhood traumas involving differentiation and integration lectures ;-)

Connor Wolf

I'd just solve for a constant Vf, and call that close enough

angelatlarge

Oh, @jippie was talking about himself!

And I assumed that like all good creatures that talk he was talking to/about ME!

Anindo Ghosh

@abdullahkahraman One other thing - None of the variables are written in stone. That is, 0.1 second to 0.5 seconds or even 1 second, no problems. Similarly, Vf would be anywhere from 3 Volts (white LED) to 1.3 Volts (IR LED), so I don't mind using different caps (and of course different limiting resistors) for the different LEDs. Precision is not critical, "visible flash" is key.

@ConnorWolf Yes, that would work, but once my mind blew a fuse at LED behavior changes across current levels, I just could not focus on the original problem any more. Point to note, @abdullahkahraman, that Connor is a wise man.

abdullah kahraman

@AnindoGhosh I know, I watch his videos :)

Anindo Ghosh

@abdullahkahraman I prefer watching Abba, but that's just me. :-)

abdullah kahraman

08:05

@AnindoGhosh Then, use the highest value capacitor that you want, but then, we should calculate for the worst case. Do you have any R value in mind?

@AnindoGhosh I think 330 to 470 ohms resistor with a 470uF capacitor will give you at least 0.1 sec delay when using a 1.3V cutoff LED after being charged to 5V.

Anindo Ghosh

@abdullahkahraman No, highest value cap = time constant could be in several seconds - that's not a visible flash, that's an LED that refuses to die! Standard-value R = 220 Ohms is what I calculated, for the voltage to current range I wanted.

abdullah kahraman

@AnindoGhosh But with the LED cutoff, the flash time will dramatically change!

Here is how I calculate:

Vcutoff = 5 * ( 1- e^-(t/RC)

Where t is the flash time you want.

Anindo Ghosh

@abdullahkahraman I actually breadboarded a 0.22 F capacitor, and the LED remained on for some ridiculous amount of time.

abdullah kahraman

@AnindoGhosh Oops, then I am not counting in the voltage drop on the resistor :)

Anindo Ghosh

@abdullahkahraman Now you begin to understand how I confused myself, and tied my mind into knots ;-)

abdullah kahraman

08:11

@AnindoGhosh That is pretty interesting to me now, I like math challenge :)

Anindo Ghosh

@abdullahkahraman Excellent, go for it. Let's set a limit on the flash duration - Anything from 0.1sec (minimum) to 0.3 sec (maximum), is that OK? Similarly, LED case 1: Vf = 3 V, Rled = 220 Ohms. LED case 2: Vf = 1.5 Volts, Rled = whatever suits the calculation.

abdullah kahraman

@AnindoGhosh OK

@AnindoGhosh In the first case, if there is 10mA current flowing, 220 ohms resistor will drop 2.2V on itself. 5V supply will not light up the LED.

I will make it 100 R and it will drop 1 V.

Anindo Ghosh

@abdullahkahraman invert your logic: 5v - 3v = 2v, with 220 ohms: current will be 9 mA.

@abdullahkahraman there is no current source... current is not a constant, it is a dependent variable.

abdullah kahraman

@AnindoGhosh Oh, OK..

@AnindoGhosh Mathematically, this is not possible with assuming that forward voltage drop will be constant.

Anindo Ghosh

08:26

@abdullahkahraman 220 was taken just to get a "standard resistor", since there's no harm passing 9 mA instead of 10 through an LED. 200 ohms if you want a precise calculation. 200 Ohms at 5 Volts = 10 mA, 200 Ohms at 4 Volts = 5 mA, precisely the parameters I had described.

@abdullahkahraman In other words, it is perfectly possible mathematically.

@abdullahkahraman You applied the math without applying your knowledge of LED behavior, i.e. that a 9 mA current and a 10 mA current are going to give nearly indistinguishable visual results (unless you have two LEDs at 9 and 10, and compare them). Similarly 4.5 mA and 5 mA are indistinguishable. Keep in mind that the whole flash is between a tenth and a third of a second, too brief for the eye to care much about the difference between 9 and 10 mA

abdullah kahraman

@AnindoGhosh OK, I will get back to you.

abdullah kahraman

08:53

@AnindoGhosh Seems like 100uF will do the trick, along with 220ohms resistor.

Anindo Ghosh

@abdullahkahraman calculation basis?

abdullah kahraman

@AnindoGhosh SPICE :)

Anindo Ghosh

@abdullahkahraman hahahaha the empirical method instead of the mathematical one!

abdullah kahraman

Anindo Ghosh

@abdullahkahraman So you converted a mathematical challenge to a modeling one :-)

abdullah kahraman

08:58

@AnindoGhosh hahahha

PeterJ

09:11

@CamilStaps, I saw your chat ping this morning, but it was 4:30AM and I just got up to go to the loo and checked first posts from my phone while I was up which probably answers your question ;-)

user61389

@PeterJ haha okay :)

user61389

I'm out, bye!

abdullah kahraman

0

A: Switching 12V with an active low 5V signal

You can achieve this with two NPN transistors as shown below. As you can see, whenever a 0V signal is given, 12V is seen in the output, and whenever a 5V is given in the input, 0V is seen on the output. Let's see how it works. First of all, let's start with the scenario where the input is 5V, or...

@CamilStaps Bye!

Anindo Ghosh

@abdullahkahraman I would consider using a BJT with a HFE in the 1000s for the first transistor.

abdullah kahraman

@AnindoGhosh I think he has lots of 2N3904 in hand. But why is that?

Anindo Ghosh

09:26

@abdullahkahraman Well, high DC gain at the first step, so fast switching at output... plus high gain BJTs are generally lower current spec while power BJTs have lousy gains in the 10s... Not that you need a power transistor for a measly 30 mA of course.

abdullah kahraman

@AnindoGhosh Oh, I see.. But in this case it will be OK, right?

Anindo Ghosh

@abdullahkahraman See, the smaller the gain, the slower the transition between 0 and 1. A high enough gain, and you've created a really sharp-knee comparator switch

Hey is it no longer possible to sort a digikey search by price?

@abdullahkahraman You got my vote, though.

abdullah kahraman

@AnindoGhosh Look at the left, they have moved the column

@AnindoGhosh Thank you!

Anindo Ghosh

@abdullahkahraman Darn! Thanks :-)

abdullah kahraman

@AnindoGhosh lol, also, the quantity is there, on upper side..

Our lecturer gave us a final project. We need to create a PLC. I am going to use a PIC16F887 and this and this source, and I am done :)

Stacey Anne

13:39

is it better for me to specialise in a specific area of firmware design, or get exposure in a lot of different projects/applications? (from an employability POV)

yogece

@StaceyAnne hi stay here some other would give answer for you

abdullah kahraman

14:11

@StaceyAnne What are you specialized on, currently?

Stacey Anne

I spent 3 years working as a firmware designer in the defence industry writing firmware for radar systems in VHDL. Now I'm writing firmware for MIT that's in the medical field in VHDL (both DSP related), but I'm wondering if it's doing damage to my career if I want to go back to defence. I feel like I've grown a lot as a developer, but am still a bit concerned.

abdullah kahraman

@StaceyAnne What damage do you think it could do to your career?

rawbrawb

14:31

grEEts all

Anindo Ghosh

grEEtz :-)

@StaceyAnne I'd say diversify - that way, if a great employment opportunity comes up, you're more likely to have the skills.

abdullah kahraman

@rawbrawb Hi!

rawbrawb

@StaceyAnne the short answer is, that some people will say, stick to one area, and some people will say diversify. And you will run across both types, the ones that want you to stick in one area probably have a limited view of what engineering is comprised of, and will be suspicious. The ones that would like to see diversity will not judge you as harshly for not having diversity.

For most people who understand the creative nature of engineering, diversity is more important especially if you are able to see the patterns and the commonality that links everything together. I would argue that you don't want to work at places that do not understand the creative value

2

vvavepacket

@rawbrawb how about if u diversify, then you miss the opportunity of becoming a master to a specific field

rawbrawb

14:47

engineering is after all about finding solutions to problems, the greater the exposure the better the result. However, it is important that you show your transitions to have been because of a logical progression. If on your resume you have "left company because everyone there was a ****" that is bad. You want to have moved because of positive reasons, but without appearing too mercenary.

Your around the world tour would really make you stand out if your resume crossed my desk. In a positive way

2

@vvavepacket The only aspect of that that is valid is the domain specific knowledge for the market and the customer relationships.

abdullah kahraman

When an NPN transistor fails, what is the probability that its CB junction will be shorted?

rawbrawb

@vvavepacket there is also the aspect that we are assuming a certain competency. Some people may need to be in a field for years. I also judge ability by innovation ability, that may not be others criteria, but then I'd argue they aren't an expert.

@abdullahkahraman it's possible

abdullah kahraman

@rawbrawb Thank you :) Also, people in various forums say the same.

Stacey Anne

@rawbrawb, that's really reassuring. I realised after I left my previous employer how much I'd missed just because a company can get stuck in the rut of doing things a certain way.

but then a company might like being able to teach people to do things the way they want things to be done

rawbrawb

@abdullahkahraman the probability will depend upon construction, a mesa etch BJT may not spike that way as readily but once it gets hot who knows.

Stacey Anne

14:57

Anyone have any idea where I can find a simple practical formula for bootstrap capacitor values for MOSFET drivers?

rawbrawb

@StaceyAnne That is the key, and they may only value that. SO you have to realize that yes, you will give up something. There is no one answer. But rather what type of people do you want to work with. Myself I always look for people who think differently because it gives an opportunity to learn and grow. But you will be closing some doors for sure, I would hope that other and more doors open up.

Anindo Ghosh

@StaceyAnne And perhaps more interesting doors, rather than ones leading to that cart rut. :-)

rawbrawb

@scott-seidman here is a link to some early NASA pictures featuring a lot of NASA Ames that we were talking about gizmodo.com/…

David Kessner

@StaceyAnne That is not always a good thing.

rawbrawb

@AnindoGhosh I'll reply to your stuff in about 12 hours or so, gotta go to a conference so I'm away for most of the day.

Anindo Ghosh

15:04

Just for general amusement: One of the best engineers I know, began with a degree in medicine, worked as a GP for a couple of years, then went on to obtain advanced degrees in surgery and gynecology, was a successful specialist at a major hospital, then decided he likes software. He switched, then went on to found an electronics firm that produces India's most significant contributions to medical electronics - all original IP, all low-cost devices that perform at least as well as ...

... their big-brand western competitors. He then moved on (still owns that business) to corporate productivity software training, and today runs a roaring business in teaching people how to get the best productivity out of MS Excel, MS Project, Sharepoint, and so on.

Somewhere along the way he also became a Microsoft Regional Director (that's not employment or contract, it's an honorary position like an MVP), and he also dabbles in industrial electronics. Now that's diverse.

@rawbrawb Cool, have a great conference.

Stacey Anne

@DavidKessner, referring to "a company might like being able to teach people to do things the way they want things to be done"?, or before that?

vvavepacket

@AnindoGhosh really a well faceted person. he tour different worlds

Anindo Ghosh

@StaceyAnne A company like that, do they issue horse blinkers to you at the joining formalities?

David Kessner

@StaceyAnne Often times, companies want things done a certain way but that way is wrong. I've seen this destroy many R&D teams.

@AnindoGhosh Horse Blinders.

rawbrawb

@DavidKessner you're my hero today! you nitpicked the nitpicker! but then he may be using the British affectation so I can't be sure.

;)

Anindo Ghosh

15:10

@vvavepacket Yup, he never ceases to impress me. After we met and became great buddies at a series of Microsoft TechEd and DevDays events back in the mid 90s where we were both speakers, he decided he wants to be a photographer as well. Not going to win any awards in that endeavor, though, as I keep pointing out to him ;-) I'm going to show him this chat when he comes over for a drink next week.

abdullah kahraman

yogece

@AnindoGhosh hi sir i couldn't program my ATmega8 using arduino uno as aprogrammer.you got any idea

abdullah kahraman

I like how vehicles are parked, lol

Anindo Ghosh

@DavidKessner Yup, well played! I googled, to find that what we call horse blinkers in Indlish, should actually be called blinders.

vvavepacket

@AnindoGhosh r u well versed in photoshop sir?

user61389

15:11

Hi, hello

Anindo Ghosh

@yogece Nope, I've not managed to go there yet, so no.

yogece

@AnindoGhosh then can i post that ques here

rawbrawb

@AnindoGhosh not that you'd admit ..... ;)

David Kessner

@CamilStaps Hullo.

Anindo Ghosh

@vvavepacket I've taught it, and for a period I provided photoshop services to fellow photographers. So yes.

@vvavepacket But not the most recent versions, since I never upgraded after CS5, cannot justify the cost.

rawbrawb

15:13

Bye all!

Anindo Ghosh

@yogece Of course. As long as a question is well researched, it's always good - add in the links to the blogs or articles you tried to follow, that you mentioned in chat yesterday.

yogece

@a

Anindo Ghosh

@rawbrawb Oh, I admit everything :-) I lack "the filter".

@yogece @a to you too.

yogece

@AnindoGhosh yes i do

Anindo Ghosh

@yogece You do what?

yogece

15:15

@AnindoGhosh i post the ques

Anindo Ghosh

@yogece XLNT

vvavepacket

15:50

is this valid? verilog

wire [8:0] sum.ext;

assign sum2 - sum.ext [ 9 : 1 ] ;

disregard the upper post. here is the proper one puu.sh/2Zw4i.png

is accessing sum_ext[9:1] valid/legal? coz we limit sum_ext to only 9 bits namely [8:0]

coding_corgi

16:04

Yo yo yo!

vvavepacket

yo coding1

coding_corgi

@vvavepacket Yo!

coding_corgi

16:51

@nyone here?

vvavepacket

17:23

im here

coding, i see that ur interested in atmega stuff

user61389

@coding_corgi sometimes there's activity here, sometimes there's not. Constantly saying it's quiet doesn't really help.

The Photon

@vvavepacket I think it's not valide because sum_ext[9] has not been declared.

vvavepacket

thanks thephoton for your response

user61389

(And now I have a meeting, bye.)

The Photon

You could do {1'b0, sum_ext[8:1]}, for example, if you want to right shift.

vvavepacket

17:27

bye camil

The Photon

@rawbrawb In my experience, I have to work in a particular field for 3-5 years before I really start to understand that area in depth. What are customer expectations and how all the elements of a system tie together to solve the customer's problems.

And often you need that depth to solve the really hard problems.

@StaceyAnne, but I don't think that means you have to be in or out of the defence field. You could be working on remote sensing for medical tomogrophy or for defence radar and still be gaining depth in that area.

jippie

17:52

@AnindoGhosh what's up?

@angelatlarge check my profile

good morning @all

angelatlarge

@jippie Yeah, it eventually dawned on me:

10 hours ago, by angelatlarge

Oh, @jippie was talking about himself!

@jippie Congratulations

jippie

@angelatlarge thanks, although it would have been nicer if it was a badge with a really cool name. like transconductance or applied-nanotube-electronics

angelatlarge

@jippie Or plz-sent-teh-codez ?

jippie

@angelatlarge wasn't that tag nuked by someone evil?

Transcript for