Electrical Engineering - 2016-08-22

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4:49 AM

Morning all.....

I'am studying about the transistors. It's 10:30 am here but I'm sleepy :( . This sleepiness is becoming like Wall between me and my studies. So trying to break it :P

Well, Hope you all well.

5:43 AM

@KeremZaman I'm no expert in H-Bridges, but it seems to me that you have the IR2109s connected wrong. The IR2109s should be driving transistors diagonally through the motor rather than one above the other as your diagram has them. The way they are, they are making a short from the motor drive voltage to ground with each PWM pulse. Not surprising that something(s) burn out.

6:02 AM

@KeremZaman At any rate, I think you ought to post this question on the main site rather than leaving it here in chat. Even if I'm right about the IR2109 connection, there are probably other things to consider. You will get a more comprehensive answer on the main site. Include your circuit diagram and a link to the IR2109 datasheet in your question.

4 hours later…

10:07 AM

Hello everyone!

I was searching for some questions about sparks created when you plug in a charger.I couldn't find any.It looks like they vanished..

Do you remember any,by chance?Can anyone point me to one?

2 hours later…

11:54 AM

Note to self: when insulating Hot water Pipes, you notice the efficiency of the insulation by quite increased temperatures of the Las bit of pipe you work on

12:36 PM

@PlasmaHH Note to PlasmaHHHHHHhHhHh; that's why most people work on an inactive system or failing that, backwards.

1 hour later…

2:01 PM

@KeremZaman Having airwires (yellow) is asking for a failure. Try powering it without a motor connected to eliminate that variable. If you aren't getting 12V on your gate driver at any point, stop.

@W5VO @KeremZaman has opened a question - electronics.stackexchange.com/questions/253572/…

2:40 PM

@PlasmaHH Depends on what you're looking at. If this is feeding a baseboard heat system or some such, excessive heat of the pipes can mean the water isn't getting where it needs to!

@ScottSeidman There are half-bridge gate drivers

it's much more common at higher voltages and/or powers

@W5VO Thanks. I imaging they're for MOSFETS hard to drive at digital levels?

@ScottSeidman Yeah, that chip is intended to take a logic-level input, amplify it to 0-12V, and level-shift it for the high-side device

it's really more about the high-side level shifting and sometimes shoot-through protection

and it also lets you use 4 NFETs in your bridge instead of NFETs and PFETs

3:01 PM

@Asmyldof in a circular pipe system backwards is relative

@ScottSeidman it's a circle for hot tap water

@PlasmaHH Most places don't have a closed circulation loop for hot water. They just let the cold water run out of the hot tap until hot water comes out.

Branden Boucher

I have a VHDL/FPGA question. As I was reading a book on VHDL, I noticed one of the samples was a clock divider using a counter Variable (not signal). It seems like the value of the variable is maintained even after the Process block, it is defined in, has finished. Is that a correct assumption?

3:37 PM

@PlasmaHH backflow point is colder when you start than when you end, while outflow point of the heater is always hot, so logic dictates, asI tried to point out, that you start at the backflow, so you limit the time you're working with hot pipes

@BrandenBoucher it's been a minute but if i recall correctly, yes, you are correct, variables are maintained

gmvhdl.com/variable.htm

Branden Boucher

@TheNoonMoose, thanks!

3:53 PM

iirc they can make synthesis pretty difficult sometimes though

like if you're doing vhdl for sim or educational purposes, doesn't matter much, but if you're actually trying to get a program running on an fpga, well, just keep that in mind

6

Q: How is a VHDL variable synthesized by synthesis tools

I know two ways in which a VHDL variable is synthesized by synthesis tool: Variable synthesized as Combinational logic Variable synthesized as a Latch unintentionally (when an uninitialized variable is assigned to a signal or another variable) What are the other ways in which a VHDL variable ...

vhdl synthesis rtl

that answer actually makes it sound like not even a problem but certainly a thing to keep in mind

Branden Boucher

From what I've heard, you do your best to avoid variables anyways. It was just not made clear.

4:31 PM

@JRE i have never been Fond of living in "most places"

Yay, a question by Olin, looks like even at his age you wonder about things ;)

3 hours later…

7:22 PM

user image

10 Unit manual assembly in a day

Not too bad

user image

Also turns out my 60 degree angled sides are nearly perfect. Always a happy surprise

Cool.

Gotta improve my dosing a bit with the new dispenser, paste and old oven

And after this really have to start building the new oven

7:48 PM

@Asmyldof What is the role of the big Wurth magnetic, if that's not a secret?

7:59 PM

i would appreciate any info you can share about what in the world we're looking at and why it needed to be a hexagon

@NickAlexeev It is used by the onboard Atmel and a feedback network to create a higher voltage drive from a Li-Ion at any state of charge to then get a consistent 180Vp-p on a piezo element :-)

@TheNoonMoose Because designers and no extra fee for a good customer (i.e. me)

haha neat man it looks great

And as a bonus when seeing bare boards people here (most notably @ThePhoton) suggested digital Katan, which I am DEIFNITELY going to develop now once I have budget for custom made displays

Maybe more of a table-top Sid Meyer's

I wonder how "digital" it makes sense to make the board

(from a Catan standpoint)

as you have secrets and random selection

Well, sure, that's why I thought of making it more of a table top Sid Meyer's

Oh, that can all also be worked into digital

localised transponders and such

8:07 PM

a good point

Players with their own rings to transpond with

But The Sid idea, I mean, at set moments stuff reveals on tiles, and people discover suddenly they want to fight for whole different areas

make a "board" that is their "hand"

With a TRNG driving what is where....

I'm trying to overcomplicate things by not allowing a graphics display

It will have a display

That's the whole fun part

8:09 PM

too "easy"

In case of Catan like games people get an iPad with their private stuff

too "easy" to make that all work just like catan, rather than having the same fixed tiles with a transistor on top?

Which does.... something

Anyway, I'm going back to Firmware Development :-)

Need to improve the scanning algorithm to find the characteristic poles and zeroes of the attached piezo, so the device can predict whether it's dirty or not

8:56 PM

dirty or not? so its a porn analyzer?

Turns out ESP8266'es don't like 13.5v on their VCC.

no shit sherlock

Also, methinks I should reset the startup preset on my Korad psu.

And perhaps pay a little more attention before pressing the Output Enable button.'

Branden Boucher

I think it all depends on what you're planning to use the ESP8266 for

Well, it would certainly work well as an electronic load now.

9:01 PM

@BrandenBoucher Golf ball marker

Warning sign

Draws about ~2 amps now

How about a hand warmer?

Branden Boucher

I was going to say small heater

But I think Golf ball marker would have been one of the last things I thought of

Or an adequate "minimum load" for those voltage regulators requiring such.

(shamelessly stolen, of course)

Branden Boucher

we see that

I wonder just how salvagable it would be

if there's like an internal reg that took one for the team

9:04 PM

At 2A? It's dead.

Oh yeah, did I tell you guys about the time I applied -15 volts at ~40a across the only prototype of our product one day before a meeting with new partners?

We were supposed to give a demonstration.

@Giskard42 That's usually how you learn to always design with polarized connectors for power.

Or at least a crowbar protection circuite

Well, I suppose we did have that

To some degree or another

@ThePhoton The connectors would have been polarized, but we were running from a 12v battery, with spade connectors

Several things caught fire very quickly indeed

And we did not give the demonstration.

"Ah, tosh. Dear investors, it seems my colleague has just triggered the self-destruct function, we built in, in case of theft. He seems to have foolishly left the wireless dongle in the office, out of range of this meeting. Well, you have now seen how safe your IP investment is with us, and we can show you the preliminary test results. In three weeks we will have a new and improved version."

"Self-destruct function." That's great. I'm stealing that.

9:19 PM

I have once opened with similar. I'm such a bald faced liar the CEO asked, full of credulous wonder "Oh, really? Interesting! Did you add that right away?"

Rapid Unplanned Entropy Increase Device.

To which my copresenter snorted and I admitted it was levity to lift spirits at the loss

Luckily, I also always build 3 or more

Aaaaaannndd back to FW

And, @PlasmaHH No. NO! Just No! Back in your kennel.

@Asmyldof to work at the entropy reversal device?

Dude, who borrowed the multivax?

LET THERE BE LIGHT

*multivac

9:48 PM

@Giskard42 Somebody's going to invent polarized spade lugs someday and make a killing.

I don't know

Fitting spade connectors through a polarization film might be hard.

I hear that if you connect two Anderson Multipole connectors together, they destructively interfere

And spontaneously form a pair of dean connectors

The energy it takes to remove a dean connector is exactly the same amount of energy that's needed to form another pair.

Altium: Leading cause of repetetive stress injury in the electronics industry for over 20 years!

Here's another "SE or Darwin Awards?" entry:

14

Q: Drilled into studs, light flickered momentarily but everything else seems fine now - should I be worried?

I was installing shelving in my closets, when drilled a hole into studs, the lights flickered momentarily for 2 seconds. I stopped drilling, and everything else seems fine now. The circuit didn't break and the lights are no longer flickering. There doesn't seem to be any sockets around the swi...

10:08 PM

@ThePhoton Which part of Altium are (were) you struggling with?

@NickAlexeev The moving the mouse all the time all day part.

10:50 PM

@ThePhoton As opposed to what kind of design work, exactly?

@Asmyldof Pencil and paper? Even working on the keyboard isn't as bad as a mouse.

@ThePhoton I thought you had a repetitive stress disorder from yelling at Altium.

@ThePhoton It's very long ago that I was able to create something "sufficiently impressive" in EE design with only a keyboard

@Asmyldof Just shift over to FPGA design

That's like saying "start developing firmware", somehow I don't consider those design really.

Design to me is something you can't fake your way through in for at least 3 years by following a list of rules or steps every time without anyone noticing

there's a few too many words in that sentence, but my exhaustion doesn't allow to identify them properly

Guess I'm just going to be hoping it's still legible

10:59 PM

@Asmyldof You think just because it requires a mouse, people don't fake their way through pcb design?

Yes, they do, but I have seen them fired/project cancelled more often than not

May also be because I'm mainly concerned with low noise Analogue and or high reliability, where (bull)shit hits the fan quicker than a company where they make, eh, say Atmel based experimenter boards in Italy with wanky names

On the other hand, it's also annoying that their crap doesn't work well in my field, because they make getting decent projects that much harder.

If you make an error in PCB design, and you know how to fix it, it will be a while till you can get a PCB without an error. With firmware, you can usually fix an error a lot more quickly. As a result, firmware doesn't require as much design upfront. Firmware enjoys rapid prototyping environment.

I'm going to put a lid on my ranting now... though I'm not feeling ranty... and toothbrushies

@NickAlexeev Firmware, done properly, also requires quite a bit of planning and set-up comparable to a design loop of hardware.

Not saying your point isn't true, but a keen eye can still separate weed and chaff

Requires a pretty keen eye though

@Asmyldof Firmware is much more malleable than PCB. Firmware is challenging, because it often has more features than PCB. (To be extra silly, I can compare the number of lines of code to the total number of pins on the PCB.)

PCB design is challenging, because it requires more foresight. Plus, some PCB errors are difficult to diagnose.

@NickAlexeev This is pretty much a toss up between FW and PCB. IF you don't partition and group your firmware plan properly you also end up with a shitstorm of re-locating code or untransparent maintenance procedures before your project is a year in.

People often happily ignore that, because usually a year in, people in the world are already using your messy code and management is fine with that, so long as the crashes and complaints can be handled by existing staff

11:14 PM

A good digital designer is a good digital designer and a crappy one is a crappy one, same as pcb guys.

@ThePhoton My only real point was that to me design is harder to fake, because the rules aren't 1,2,3. More like 1, unless 5, with the exception of if you see A2, 2, but only if not 3 or 9.

Anywhuu, I'm going to take a nap.

11:36 PM

@ThePhoton ... but yeah, Altium lacks in the hot key department. (Or may be I haven't got used to it yet after OrCAD.)

@Asmyldof And that's not true in digital design?

@Asmyldof There are no rules. There are only virtues.

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