Author Topic: Worst PCB Ever?  (Read 15074 times)

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Offline StillTrying

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Re: Worst PCB Ever?
« Reply #50 on: June 02, 2017, 01:01:08 am »
If the crossing tracks really were joined to each other there'd be a round blob at the crossing points, so it should work OK. :)

I think it's real.
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Offline Someone

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Re: Worst PCB Ever?
« Reply #51 on: June 02, 2017, 03:01:43 am »
This has got to be a joke. There's no way a group of students made it to 400 level classes without being able to do better than that.
yes, it's obviously a joke...
You've probably never taught students then, those lagging behind and scraping their way through the prerequisites can have astoundingly poor understanding of the material and get by with combinations of "group work" where they don't contribute anything that helps the group (or hinders it), "tutoring" assistance with their assignments, and in extreme cases "substitutes" in tests. The really surprising part is they don't see any moral issues with it and will justify how they are entitled to all the assistance they need to pass.

The best example I can provide was a final year electronic major, who given all the resources of the laboratory couldn't measure or even describe current. You can't even laugh about it at that point.
 
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Offline mdszy

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Re: Worst PCB Ever?
« Reply #52 on: June 02, 2017, 03:06:09 am »
This has got to be a joke. There's no way a group of students made it to 400 level classes without being able to do better than that.
yes, it's obviously a joke...
You've probably never taught students then, those lagging behind and scraping their way through the prerequisites can have astoundingly poor understanding of the material and get by with combinations of "group work" where they don't contribute anything that helps the group (or hinders it), "tutoring" assistance with their assignments, and in extreme cases "substitutes" in tests. The really surprising part is they don't see any moral issues with it and will justify how they are entitled to all the assistance they need to pass.

The best example I can provide was a final year electronic major, who given all the resources of the laboratory couldn't measure or even describe current. You can't even laugh about it at that point.

I was about to rage about "How could someone like that even be allowed to get a degree????!!!" but then realized: they're completely unhireable and will just end up getting a crappy job unrelated to their degree , which they likely are in massive debt for!
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Offline Someone

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Re: Worst PCB Ever?
« Reply #53 on: June 02, 2017, 03:12:55 am »
If the crossing tracks really were joined to each other there'd be a round blob at the crossing points, so it should work OK. :)

I think it's real.
Thats the sort of thinking that would lead to this. You could produce clever laboratory work where the students would need to simulate the design and then measure the real world and determine why it differs, very few would ever be able to come up with the answer. I could fully imagine a group of clueless students (having failed to attach themselves to competent partners/groups) sitting around the schematic in simulation and just dropping that onto a board without a DRC or any forward annotation.
 

Online blueskull

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Re: Worst PCB Ever?
« Reply #54 on: June 02, 2017, 04:10:29 am »
I've mentored quite a few students on hardware and software design. The bottom line is, anything can happen with undergrad students.
Some can't write a hello world in their 4th year (yeah, I know they are EE, not CS/CE, but come on).
After 3 credit hours on C, 1 credit hour on C lab session, 3 credit hours on MFC GUI programming, 3 credit hours on embedded systems, 3 credit hours on Matlab and 3 credit hours on Verilog, some still can't write a hello world in any language.
On the other hand, there are some quite bright undergrad students that can take on a fairly large project with new technology on his or her own, or even manage a small team to solve an even bigger problem.

When I graduated, some of the best capstone projects involve computer vision, robotics and advanced communication and security, essentially a complete IoT system. While some others are as simple as setting up an MCU board and printing a string based on ADC input, essentially 10 lines in Arduino.
 

Offline jwm_

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Re: Worst PCB Ever?
« Reply #55 on: June 02, 2017, 04:39:46 am »
My guess about how this came about is that they attempted to split up the work.among the 4 person team. One person got schematic, another got theory and one dude got the make the PCB task. PCB guy probably slacked to the last minute, claiming he was on top of it, not asking for help because he already said he started it, until the night before it was due. Whipped this up, but wasnt the schematic or theory guy so didn't realize it wouldn't work. Brought it to his team members a half hour before it was due and they were like.. WTF. But soldered the components in anyway to turn it in so as to not get a zero, horribly embarrassed the whole time and shooting daggers at the PCB guy.  Not a fan of group assignments.
 
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Online james_s

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Re: Worst PCB Ever?
« Reply #56 on: June 02, 2017, 05:43:31 am »
I rarely liked group assignments either. With the right group they worked really well, but it was too easy to end up with some slacker who was just along for the ride.
 

Offline CJay

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Re: Worst PCB Ever?
« Reply #57 on: June 02, 2017, 07:16:15 am »
I've mentored quite a few students on hardware and software design. The bottom line is, anything can happen with undergrad students.
Some can't write a hello world in their 4th year (yeah, I know they are EE, not CS/CE, but come on).

On the other hand, there are some quite bright undergrad students that can take on a fairly large project with new technology on his or her own, or even manage a small team to solve an even bigger problem.


I found the best students were always those who took the courses to certify their skills, I.E. they were long term hobbyists who were probably, in knowledge terms, already at degree level before they started and just needed to be taught how to apply it.

They were the 'self starters' who, when tasked or even just shown a new technology, devoured it if it interested them.

One of my responsibilities in a long left job was to manage university students on work experience placements, they were almost without exception, utterly bloody useless, most freely admitted they'd taken the course because of the financial prospects and not because of any interest in it.

The very best, one who stands out in my memory (I'd love to know what happened to him) was a guy called Andy Papageorgiou who was in the middle of designing a Transputer based machine that got published in one of the electronics magazines of the time (mid 80s, if anyone has scans...).
 

Offline Red Squirrel

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Re: Worst PCB Ever?
« Reply #58 on: June 02, 2017, 07:43:28 am »
lmao at the overlapping traces.   I think they were so used to seeing it in circuit diagrams where if you don't put a dot it means the lines arn't touching, that they actually took that literally in the PCB design.  :-DD
 

Offline Zbig

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Re: Worst PCB Ever?
« Reply #59 on: June 02, 2017, 09:44:50 am »
I've had a masters in EE tell me that its impossible for the battery charger to be outputting 2A at 12V because the benchtop supply it was being powered from was only showing 1.2A of output (at 24V).  He simply could not understand that a device could output more amps than it was taking in.

I've had a teacher in my technical high school look down at me in disgust because, during the lab class, I haven't hooked up an ammeter just after the PSU (as the instructions called for) but took the readings off the meter conveniently built into the PSU instead (only some newer ones they've got had them). She said something along the lines of "and how on Earth do you think the current would have ended up inside the power supply!?". She just couldn't wrap her head around the idea that the current doesn't magically appear on the positive output terminal and then disappear to another dimension into the negative one. It was just too much for her to comprehend. Jeez, how I hated that woman. I think it was also her who insisted that the optocoupler working principle as explained in the book was just a kind of a "metaphor" to make understanding of the concept easier as she figured it would be impossible and/or silly for an actual LED to be shining on an actual phototransistor inside the IC package :palm:
 
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Offline CJay

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Re: Worst PCB Ever?
« Reply #60 on: June 02, 2017, 09:49:03 am »
I think it was also her who insisted that the optocoupler working principle as explained in the book was just a kind of a "metaphor" to make understanding of the concept easier as she figured it would be impossible and/or silly for an actual LED to be shining on an actual phototransistor inside the IC package :palm:

Your opto coupler comment piqued my interest, I've always taken it as read that there was a LED and phototransistor inside the package, probably as two separate die with some sort of transparent filler between, now I need to go and chisel one open to find out for myself :)

*edit*

Ah, the 'net to the rescue, x-ray images are brilliant. Though there's a 4N35 that's going to meet the Dremel this evening anyway...
« Last Edit: June 02, 2017, 09:51:48 am by CJay »
 

Offline TerraHertz

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Re: Worst PCB Ever?
« Reply #61 on: June 02, 2017, 12:17:52 pm »
While I agree with everyone saying there are plenty of completely clueless electronics undergrads, I still think this is someone trolling. The original post is this:
   http://imgur.com/gallery/i8MEXct
Where there's zero evidence this was real.
If the photo was taken in a university lab environment, why not include some context in the frame?
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Offline Cerebus

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Re: Worst PCB Ever?
« Reply #62 on: June 02, 2017, 12:37:23 pm »
I was about to rage about "How could someone like that even be allowed to get a degree????!!!" but then realized: they're completely unhireable and will just end up getting a crappy job unrelated to their degree , which they likely are in massive debt for!

Yeah, the problem is that unrelated job is "Management" and you get to call them "Boss".  ;)
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Offline pitagoras

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Re: Worst PCB Ever?
« Reply #63 on: June 02, 2017, 12:41:54 pm »
What's wrong with crossing traces? Electrons that come from the left continue to the right because of momentum, electrons from the top continue to the bottom... it's simple physics people!  :-DD

They could have even fix it with miniature traffic lights in the corners
 

Offline igendel

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Re: Worst PCB Ever?
« Reply #64 on: June 02, 2017, 12:57:46 pm »
What's wrong with crossing traces? Electrons that come from the left continue to the right because of momentum, electrons from the top continue to the bottom... it's simple physics people!  :-DD

They could have even fix it with miniature traffic lights in the corners

Now that's some original, out-of-the-box thinking! You're hired!  :-DD
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Offline madires

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Re: Worst PCB Ever?
« Reply #65 on: June 02, 2017, 01:06:07 pm »
Promising candidate for a senior consultant at Accidenture  >:D
 

Offline ZeTeX

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Re: Worst PCB Ever?
« Reply #66 on: June 02, 2017, 01:27:11 pm »
What's wrong with crossing traces? Electrons that come from the left continue to the right because of momentum, electrons from the top continue to the bottom... it's simple physics people!  :-DD

They could have even fix it with miniature traffic lights in the corners
And add a hospital in case one of the electrons crash into another
 

Offline janoc

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Re: Worst PCB Ever?
« Reply #67 on: June 02, 2017, 02:00:14 pm »
I was about to rage about "How could someone like that even be allowed to get a degree????!!!" but then realized: they're completely unhireable and will just end up getting a crappy job unrelated to their degree , which they likely are in massive debt for!

You don't realize that these guys are not there to get hired as EE (or another type) engineer. They are there to get a degree, often choosing the school only because it was easiest to get in or simplest to get visa or having cheapest tuition. Then they go home and become managers.

Not joking - had exactly this happen with some international students. Getting western education is a matter of prestige there, regardless of whether the student needs it or wants it. So they "study". All they really want is the graduation paper, in most cases they will never touch the subject they have studied in their lives anymore. One such guy got almost expelled for cheating, totally incompetent, barely scraped by but colleagues let him graduate. Now he is a C-level exec at a major company in Singapore laughing at how stupid we were working for the pittances we were paid.

I have met even a French guy (so it is not just international/third world stuff) who has been *proud* (and bragging about it) that someone else wrote his thesis and did his final project for him (under his "management"!). He was dumb as a brick, of course, anything he touched with his management "skills" turned into a major clusterfuck. And that fraud has almost managed to get a tenure at a fairly prestigious technical university by bullying ("managing") others to credit him for work he didn't do. He would have got it if there wasn't for one prof who actually knew him personally and put a kibosh on it by vetoing the process.

« Last Edit: June 02, 2017, 02:08:16 pm by janoc »
 

Offline tatus1969

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Re: Worst PCB Ever?
« Reply #68 on: June 02, 2017, 05:31:18 pm »
What's wrong with crossing traces? Electrons that come from the left continue to the right because of momentum, electrons from the top continue to the bottom... it's simple physics people!  :-DD

They could have even fix it with miniature traffic lights in the corners
Don't underestimate the abilities of these tiny little electrons, they have gone through worse than that. Below is a diagram showing their tricks with a BJT. Don't believe all that theoretical explanations with semiconductor junctions and charge carriers, this is how they really do it!




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Offline pitagoras

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Re: Worst PCB Ever?
« Reply #69 on: June 02, 2017, 05:43:07 pm »
What's wrong with crossing traces? Electrons that come from the left continue to the right because of momentum, electrons from the top continue to the bottom... it's simple physics people!  :-DD

They could have even fix it with miniature traffic lights in the corners
And add a hospital in case one of the electrons crash into another

Problems arise when there is no electricity, traffic lights would not work, so we need also little policeman to take over the situation.
 

Offline evb149

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Re: Worst PCB Ever?
« Reply #70 on: June 02, 2017, 05:51:29 pm »
It works, here's proof:
https://www.eevblog.com/forum/rf-microwave/retro-raytheon-microwave-amplifier/msg1219908/#msg1219908

What's wrong with crossing traces? Electrons that come from the left continue to the right because of momentum, electrons from the top continue to the bottom... it's simple physics people!  :-DD

They could have even fix it with miniature traffic lights in the corners
And add a hospital in case one of the electrons crash into another
 

Offline Red Squirrel

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Re: Worst PCB Ever?
« Reply #71 on: June 03, 2017, 05:08:33 am »
What's wrong with crossing traces? Electrons that come from the left continue to the right because of momentum, electrons from the top continue to the bottom... it's simple physics people!  :-DD

They could have even fix it with miniature traffic lights in the corners
And add a hospital in case one of the electrons crash into another

Problems arise when there is no electricity, traffic lights would not work, so we need also little policeman to take over the situation.

Or just make it a 4 way stop, you can even put "no left turns" and "no right turns" signs to ensure they go the right way.  Violators are just seen as noise and are the reasons for error correction further down the line, so you need a correctional facility in the circuit.
 

Offline German_EE

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Re: Worst PCB Ever?
« Reply #72 on: June 03, 2017, 07:04:15 am »
"Or just make it a 4 way stop, you can even put "no left turns" and "no right turns" signs to ensure they go the right way."

Which is roughly what a microwave circulator does, I've always thought that a little bit of magic was involved with them.

https://en.wikipedia.org/wiki/Circulator
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