Author Topic: Things derped engineers say.  (Read 35543 times)

0 Members and 1 Guest are viewing this topic.

Offline olsenn

  • Frequent Contributor
  • **
  • Posts: 993
Re: Things derped engineers say.
« Reply #25 on: May 02, 2013, 03:10:41 pm »
Quote
Quote from: ddavidebor on Today at 12:55:20 AM
You MUST drive led by voltage.

I'm not even really sure what this means.

Probably that the LED (or any diode for that matter) won't drain any current until a certain voltage threshold is reached (junction drop). Unless you plan on making use of a volatile voltage-current curve for your particular LED though, you'll need to drive the LED with a fixed current as well. Light = Power - Other Shit
 

Offline free_electron

  • Super Contributor
  • ***
  • Posts: 7373
  • Country: us
    • SiliconValleyGarage
Re: Things derped engineers say.
« Reply #26 on: May 02, 2013, 03:34:12 pm »
Newly minted engineer (NM), straight out of uni. Masters. Analog design.
Walks into my lab with 'underwhelming enthusiasm' because he is tasked with debugging an actual board as opposed to simulating it at his desk.

NM walks to large cabinet with parts , opens and closes drawers , get's a more and more puzzled look on his face and lumbers over to me.

NM: how can i tell for these small components (smd) what are resistors and caps. They all look the same...
ME: look at the label on the bins. The capacitors have their a little omega symbol behind the value.
NM: ok

NM rifles through cabinet and walks off with his 100kilo-pico decoupling cap.....

-------

PE ( paper engineer . Type that only shuffles paper around but has no practical experience. Never leaves desk ) comes to lab , has to do something on. Aboard. He is given a prototype chip and has to test power consumption on the 1.8 volt rail.
 He messes around for a while and cant get it to work . Calls for help.
I walk over there .. One huge ball of wires going everywhere.. I trace all the wires out. His ammeter wires , through lots of bananas and grabbers were both connected to the 1.8 v rail... So in essence the ammeter is shorted and connected to 1.8 volt.
I explain to him current needs to flow through the ammeter. I also explain that , in order to do that there is a nice jumper on the board that disconnects the 1.8 volt plane feeding the chip , from the regulator.

PE mucks about for another half hour and calls me over. He has blown the fuses in 3 ammeters.. I look at the wiring. The ammeter is now connected from the 1v8 regulator out to .... Ground... It is supposed to be between the pins of the jumper. It aint a voltmeter ! Anyway , we were out of fuses ( and working ammeters) so i tell him : take a bench supply , set it to 1.8 volts , connect to jumper and read the current from the supply. I walk off.

A few moments later i become awar of that typical smell of carbonised ic packages... Following my nose leads me to PE's bench....
Sure enough. The nitwit now connected the supply between the jumper pins. So he had 1.8 being made on the board , in series with 1.8 made by the supply , thereby feeding 3.6 volts into the chip...
He looks at me and say : there must be something wrong with these prototypes they all blow up at poweron...
ME : how many protos do you have ?
PE : 5
ME : how many did you try
PE : 5
ME : i guess it must be a production problem then. Its very consistent . They all blow at 3.6 volts...
PE happy trundles off to write report... Not catching on to what i just said. Sure enough during slide presentation he made a nice bullet point : all chips blow at 3.6 volts.. As this is consistent it must be a fab problem....

---
PE2 ( a different one) is tasked to design some glue logic to match a pcmcia wifi network card( pcmcia is basically isa) onto the memory interface of a chip. We want to add wifi capabilities and use simple pcmcia cards for that purpose (2001 era. Every router was built that way then)
He comes up with a circuit consisting of 11 or 12 ttl chips (74xx series). Most of em half used. Like a 7404 because he needs an inverter somewhere.... And there is an u used 7400 gate left...
I go over the schematic and manage to reduce the circuitry to 5 chips.( he used 74245 as bus switch on data . I happen to know there is such thing as a 16245 for 16 bit buses.... ) no comment on that , i just happened to know that, he didn't. That was not the problem.

I had minimized his pile of loose gates to two quad nand, a quad nor and a quad and. Or something like that. I had built an or gate from three nands. Simply make two inverters out of two nand gates, and slap on another nand gate.. A+B = not(notA * notB) . Simple boolean logic.
He doublechecked my circuit ( as he was responsible for signoff) andexclaimed this could not work. He definitely needed an or gate for the two signals and i must have made a mistake. I tried explaining him boolean rules.. But no budging on his side. Anyway, he was going to make a quick netlist in VHDL based on my schematic and send it through the simulator....

This made me print a large banner to put over his desk.. The banner said 'More TTL, Less VHDL'

---
Chinese collegue with -very- bad pronunciation...

RING.. ( telephone). We need talk abou alice. Alice no good.
???? This guy has a complaint about alice ? I look around puzzled .. I don't know any alice in the department ( i had just started there like a few weeks before ) . So i ask my collegue if they know any alice .. Puzzled looks . No, we don't have anyone in the company with that name.
I turn back to the phone and ask if he is sure he got the right guys ?
Him : Yes yes alice wok fo poi fai.
???? What the hell ? Alice.. And she works for some asian sounding guy called 'poifai' .. So i turn to my collegue and say that this dude wants to talk to 'alice' who works for some guy called something that sounds like poifai.

At this point the senior designer starts laughing and asks who i am talking to ... I give the name. .. He says , okay i know what this is about pass him to me. So we all look baffled .. And he explains :
This chinese guy has been working on the 'Netlist' for the first chip in 0.5 micrometer technology (this was 1993...)
So he found a problem in the 'netlist work for point five...'
Alice wok fo poi fai...

....
The same chinese dude drew massive crowds whenever he gave a presentation. People went there for laughs ... One meeting he was explaining a block he designed and he kept going on about some jibberish.. Lingoselelle or something like that. The senior designers were all baffled. We were used to chinglish by now but this was a rightout brainracker... Until 5 minutes later one of the seniors , who had been diggi g in the schematics exclaimed: i know what this is. It's the ringoscillator he used here:

Yes yes, lingoscelelle..

Other instances : the atela... ( talking about the altera fpga on the board )






Professional Electron Wrangler.
Any comments, or points of view expressed, are my own and not endorsed , induced or compensated by my employer(s).
 

Offline c4757p

  • Super Contributor
  • ***
  • Posts: 7805
  • Country: us
  • adieu
Re: Things derped engineers say.
« Reply #27 on: May 02, 2013, 04:06:07 pm »
NM: how can i tell for these small components (smd) what are resistors and caps. They all look the same...
ME: look at the label on the bins. The capacitors have their a little omega symbol behind the value.
NM: ok

NM rifles through cabinet and walks off with his 100kilo-pico decoupling cap.....

What!? Was his master's degree printed on toilet paper or written in crayon, by any chance?  :scared:

Quote
PE ( paper engineer . Type that only shuffles paper around but has no practical experience. Never leaves desk )
(entire story)

I have just lost the small amount of faith in humanity I had.
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline T4P

  • Super Contributor
  • ***
  • Posts: 3706
  • Country: sg
    • T4P
Re: Things derped engineers say.
« Reply #28 on: May 02, 2013, 05:00:54 pm »
"it's a current limiting power supply, the circuit can't blow up!"

That's a good one. How about "It's not the voltage that kills you, it's the current"? Can't say I've heard an actual engineer ever utter that one, but a perhaps a friend...
A guy on OCN claiming to be a electrical engineer kept on implying that  :-// and said that my argument that it's actually ohms law that is the matter and he said it's still current that kills  :-//
Bloody idiot didn't realize my point that if he phrased it like that it will saying that a 10V source can kill you given enough current |O

"Hey, Watch this shit!"

That is in the same league as
"How hard could it be?"
and
"What could possibly go wrong?"
Jeremy clarkson  :-DD

It must be a software problem.

 ;)
*points to software engineer*
The same chinese dude drew massive crowds whenever he gave a presentation. People went there for laughs ... One meeting he was explaining a block he designed and he kept going on about some jibberish.. Lingoselelle or something like that. The senior designers were all baffled. We were used to chinglish by now but this was a rightout brainracker... Until 5 minutes later one of the seniors , who had been diggi g in the schematics exclaimed: i know what this is. It's the ringoscillator he used here:

Yes yes, lingoscelelle..

Other instances : the atela... ( talking about the altera fpga on the board )
The moments that make you go  :scared:  You tell the best stories man :-DD
Being chinese myself i even found that extremely hilarious ... but yes someone with a chinese accent and doesn't have much english education will pronounce ring oscillator like that
You know why? ringo-scilator. In chinese rin = lin ... and yes i can pull of the same accent as well but it's not i wanted much chinese education since young, nope, i didn't listen to class because i couldn't be bothered with chinese and here i am ... speaking 100% english apart from the rare times i have to communicate in chinese  :palm:
« Last Edit: May 02, 2013, 05:05:00 pm by T4P »
 

Offline kfitch42

  • Frequent Contributor
  • **
  • Posts: 300
  • Country: us
Re: Things derped engineers say.
« Reply #29 on: May 02, 2013, 05:55:14 pm »
It must be a software problem.

 ;)

Q: How many programmers does it take to change a light bulb?
A: None, that's a hardware problem.

Hey! As a software guy I represent that remark!

P.S. I have used the "must be a hardware problem" excuse a few too many times.
 

Offline kfitch42

  • Frequent Contributor
  • **
  • Posts: 300
  • Country: us
Re: Things derped engineers say.
« Reply #30 on: May 02, 2013, 06:02:15 pm »
"It's not the voltage that kills you, it's the current"?

Everyone who says that should be forced to watch this:


"Its not the fall that kills you, its the landing."

 

Offline Rufus

  • Super Contributor
  • ***
  • Posts: 2094
Re: Things derped engineers say.
« Reply #31 on: May 02, 2013, 06:29:02 pm »
Everyone who says that should be forced to watch this:

Snip stupid boring video which includes a table showing you what current (that's current not voltage) it takes to kill you.

It isn't a myth he didn't bust it. It is a simple truth which needs some explaining if you are particularly dumb.
 

Offline N2IXK

  • Frequent Contributor
  • **
  • Posts: 701
  • Country: us
Re: Things derped engineers say.
« Reply #32 on: May 02, 2013, 06:31:27 pm »
Had a post-grad EE student helping out in the lab as an intern one summer. Came highly recommended, being one of the "best in his class".

Anyway, we were having some issues with computers and other equipment acting up/rebooting in one part of the building, so I gave the kid a DMM, and told him to go down and check the line voltage, as the problem seemed worse on hotter days when the line voltage tends to sag. Phone rings a couple minutes later, and he proudly reports that the line voltage is 188.8 volts (this on a US standard 120V branch circuit). Because everything was pointing to a LOW voltage problem, I was a bit dubious, and asked him to recheck the reading, but he reported that the meter wouldn't turn on. When I asked him how he got the reading, he said that he put the probes into the outlet, the display flashed up "188.8", then went out.

I then asked him what the knob on the meter was sent for, and he said "That little upside-down "U" thingy...".  Needless to say, he didn't make it through the rest of the summer with us.....
"My favorite programming language is...SOLDER!"--Robert A. Pease
 

Offline T4P

  • Super Contributor
  • ***
  • Posts: 3706
  • Country: sg
    • T4P
Re: Things derped engineers say.
« Reply #33 on: May 02, 2013, 07:59:38 pm »
Had a post-grad EE student helping out in the lab as an intern one summer. Came highly recommended, being one of the "best in his class".

Anyway, we were having some issues with computers and other equipment acting up/rebooting in one part of the building, so I gave the kid a DMM, and told him to go down and check the line voltage, as the problem seemed worse on hotter days when the line voltage tends to sag. Phone rings a couple minutes later, and he proudly reports that the line voltage is 188.8 volts (this on a US standard 120V branch circuit). Because everything was pointing to a LOW voltage problem, I was a bit dubious, and asked him to recheck the reading, but he reported that the meter wouldn't turn on. When I asked him how he got the reading, he said that he put the probes into the outlet, the display flashed up "188.8", then went out.

I then asked him what the knob on the meter was sent for, and he said "That little upside-down "U" thingy...".  Needless to say, he didn't make it through the rest of the summer with us.....
:palm:  |O  :-DD
My daily dose of fail has just arrived
 

Offline Dataforensics

  • Supporter
  • ****
  • Posts: 134
  • Country: gb
Re: Things derped engineers say.
« Reply #34 on: May 02, 2013, 08:35:31 pm »
Not really electronics, but I was doing a mixed engineering course around 35 years ago
In the last few weeks of the three years the whole class had to attend prize giving for the best paper on equipment used, mine did not win.

The winning paper was on Milling machines, during the presentation the winner was asked to stand by one to have his photo taken. He proceeded to proudly walk up to the bank of Lathes.

This probably reflects as much on his tutors!.

 
 

Offline free_electron

  • Super Contributor
  • ***
  • Posts: 7373
  • Country: us
    • SiliconValleyGarage
Re: Things derped engineers say.
« Reply #35 on: May 02, 2013, 09:04:20 pm »
Had a post-grad EE student helping out in the lab as an intern one summer. Came highly recommended, being one of the "best in his class".

Anyway, we were having some issues with computers and other equipment acting up/rebooting in one part of the building, so I gave the kid a DMM, and told him to go down and check the line voltage, as the problem seemed worse on hotter days when the line voltage tends to sag. Phone rings a couple minutes later, and he proudly reports that the line voltage is 188.8 volts (this on a US standard 120V branch circuit). Because everything was pointing to a LOW voltage problem, I was a bit dubious, and asked him to recheck the reading, but he reported that the meter wouldn't turn on. When I asked him how he got the reading, he said that he put the probes into the outlet, the display flashed up "188.8", then went out.

I then asked him what the knob on the meter was sent for, and he said "That little upside-down "U" thingy...".  Needless to say, he didn't make it through the rest of the summer with us.....

Give the kid some credit for checking the impedance of the grid ! After all you were after a voltage drop. Voltage drops are caused by imcreased resistance or impedance.. So he was on to something ...
Professional Electron Wrangler.
Any comments, or points of view expressed, are my own and not endorsed , induced or compensated by my employer(s).
 

Offline ConnorGames

  • Regular Contributor
  • *
  • Posts: 94
Re: Things derped engineers say.
« Reply #36 on: May 02, 2013, 09:14:10 pm »
Had a post-grad EE student helping out in the lab as an intern one summer. Came highly recommended, being one of the "best in his class".

Anyway, we were having some issues with computers and other equipment acting up/rebooting in one part of the building, so I gave the kid a DMM, and told him to go down and check the line voltage, as the problem seemed worse on hotter days when the line voltage tends to sag. Phone rings a couple minutes later, and he proudly reports that the line voltage is 188.8 volts (this on a US standard 120V branch circuit). Because everything was pointing to a LOW voltage problem, I was a bit dubious, and asked him to recheck the reading, but he reported that the meter wouldn't turn on. When I asked him how he got the reading, he said that he put the probes into the outlet, the display flashed up "188.8", then went out.

I then asked him what the knob on the meter was sent for, and he said "That little upside-down "U" thingy...".  Needless to say, he didn't make it through the rest of the summer with us.....

Give the kid some credit for checking the impedance of the grid ! After all you were after a voltage drop. Voltage drops are caused by imcreased resistance or impedance.. So he was on to something ...

Obviously he needs to use an LCR meter. Preferably the nicest one in the lab so he can measure low impedance accurately...
 

Offline senso

  • Frequent Contributor
  • **
  • Posts: 949
  • Country: pt
    • My AVR tutorials
Re: Things derped engineers say.
« Reply #37 on: May 02, 2013, 09:33:20 pm »
I can't really understand how all those "best of the class" are of hum... DUMB!
 

Offline free_electron

  • Super Contributor
  • ***
  • Posts: 7373
  • Country: us
    • SiliconValleyGarage
Re: Things derped engineers say.
« Reply #38 on: May 02, 2013, 09:45:35 pm »
3 day course from cadence on some new tool. Second day halfway through the afternoon. Loud snoring from the last row ... Everyone turns around to see where it comes from ... Dr Berndsen had fallen asleep ( our swedish digital design guru).

His neighbour pokes him in the ribs and Dr berndsen jolts awake and exclaims in his thick scandinavian accent. Huhuhu i fell 'asjleep'...

I took 5 minutes for the laughing to stop .... The way he said that was so funny. He had this very deep voice aaand wooulld taaaalk veeryyy sloowwlee.

Huuhuuhuu aiii fellll asjjleeep.


---

Midnight shift in the waferfab .. ( i started as a makntenance technician repairing the plasma etchers and ion implanters... )

Ring. Ion implant station 3 here. The wafer handling robot is stuck.
This was acommon problem. I was outside the cleanroom so i told the operator the clear the wafer basket and hit init. Meanwhile i would suit up and come in.
The operator says : i don't think that will work. The endstation door is open...
?? What do you mean the endstation door is open ?

( for the unwashed masses. An ion implanter is a large machine. Basically an ion gun. We have long vaccuum tube ( several meters long ) with an ion gun and a mass analyzer on one end and an endstation on the other end. This endstation has a massive door that is lifted from horizontal to vertical position. In this doo there is a heavy larg rotating , watercooled, disk with clamping mechanisms. The robot takes a wafer , and loads them in the clamp. When 25 or 50 wafers are loaded in this spinning disk the door is raised vertically, the endstation is pumped vacuum , the disc is brought up to speed and the innner airlock opens. At that point the wafers are exposed to the ion beam. As the wafers spin in front of the 'business end' of the ion gun they get implanted with the dopant material. A big electromagnet deflects the beam to scan the entire surface. )

So the endstation door is open... But .. The robot should be parked on the other endstation ( for throughput there are two of these endstations. The one that is 'up' and being i planted has the robot i. Front of it so it can load the one that is down.

So i ask again ? Where is the robot.

Sheepish answer ... Underneath the door..

Me : WHAT ? Explain that again please . Where is the robot ?
Operator : Underneath the door...
Me : HUH  ?
Operator : both doors are open. The robot is underneath the left endstation...
Me : ?!? What happened ?
Operator : well at the end of the run there was this loud bang and the door crahshed open...

It turned out one of the retaining bolts that hold the pistons that lift the door had sheared clean off. As the lock was opening the bolt gave out, the piston shot loose , ripped half the cabling out and the entire door crashed open o top of the precision wafer handleing robot. Completely crushing it i to oblivion....

So we made a plaque that said : if both doors are open you got biiiig trouble..
---

Afternoon shift. Water alarm on implanter 4. We go and check and there is water dripping from a feedr line. We find it is the connector. So we ( my collegue and i , you always work in pairs around these implanters. They are dangerous ) apply some duct tape and call plant and facilities to replace the water feed. ( that stuff is p&f work)

P&f engineer comes in and we show him where the problem is.

Now this machine has a service walkway behind it that is fairly narrow. On the back wall is the mkan breaker panel for the power to the implanter. Oneof these gass assisted rotatry type breakers. Big red handle you have to grab with two hands and rotate down 45 degrees. The gas charges then shoot the switch open.( this machine draws substantial power when in operation... 380 volts at 400 ampere.. )

Now, you have to know a bit about 'bunny suits'. The cleanroom overall is an annoying garment to keep skin flakes and other wate products of humins trapped inside and out of the cleanroom. It is a loose fitting garment with elasticised neck , wrist and ankle cuffs and an elesticised waistband. Basically a big garbage bag.. It always pulls and pinches i. The wrong spot if you need to kneel or bend. It is only good for walking or sitting on achair. Anything else it is annoying.

So this dud pulls up the legs to remove the slack i. Order to kneel down and sit on his knees half underneath the machine and fix the leaky plumbing. As he does this he basically creates a flap of material around the waistband. Ho goes through the knees , this flap of fabric hooks the breaker arm and...
 
You guessed it. -boom- fieuuwwwww ( sound of motors spinning down , compressed air escaping , ) kling , bang , kloink ( sound of vacuum valves popping open , breaking wafers, ion gauges popping )...

This dude gets up very quickly , looks at us sheepishly and goes. 'Oh sorry'... Turns around and lifts the breaker back up.. Followed by more loud booms and bangs .....

It took 3 weeks to repair the machine.... The dude was barred from ever entering the cleanroom again...

---

Main extraction voltage failed on one of the implanters. So the senior equipment engineer calls us 'freshman' overto show how you replace the main rectifier.
The high voltage generator is a large oil filled tank that takes 380 volts and makes up to 160 kilovolts from it. Full of transformers, massive capacitors , motorized variacs and other high voltage stuff. The end rectifier is a vacuum tube... It turned out the filament had popped.

So he shows us to safely shutdown the hv generator , discharge every cap usi g a special grounded stick , open the access cover , disconnect the anode wire and pull outthis vacuumtube. This thingis the size of a volleyball. Massive glass balloon rectifier.

He puts a new one in . Covers everything up and goes through the startup procedure. No power.

Drat.. Maybe we put it in wrong. This thing has a 4 pin base and you can put ot in wrong ...

So we go through shutdown, discharge, safety yadda yadda yadaa. Pull the tube, rotate it , make sure it is i right this time and firethe machine up.
The operator starts pulling beam current . At about 40 kilovolts the tube pops. Game over....

So the senior engineer gets nervous. Its the end of his shift, he is in overtime, the operators are annoyed because the machine has now been down a few hours already.

So he shoves us asided and decides to do it himself as he can do it faster. Rush rush rush .. And he forgets to discharge the anode..... He reaches i to the oil tank and grabs the tube.
Now the bunny suits are conductive ...( not dissipative but really conductive . A few kiloohms ).
This thing arcs over and hegets a massive jolt from the tube ( the suit caught most of it ,but he still got zapped good ) so he jolts up. Now. His arm was up to his elbow in this high voltage oil...

Floor ,wall ,ceiling , him and me and my collegue were all drenched in oil. He had to sit down for a while because he literally say stars...
« Last Edit: May 02, 2013, 09:49:32 pm by free_electron »
Professional Electron Wrangler.
Any comments, or points of view expressed, are my own and not endorsed , induced or compensated by my employer(s).
 

Offline ddavidebor

  • Super Contributor
  • ***
  • Posts: 1167
  • Country: gb
    • Fermium
Re: Things derped engineers say.
« Reply #39 on: May 02, 2013, 09:51:56 pm »
I can't really understand how all those "best of the class" are of hum... DUMB!

school and all-day problems are different.

everyone with good memory and good brain can have 10+ at school.

you only need to do thing that someone has alredy teach you, and you need to do in the same way.

outside school, is the opposite.

you have not pre-make answer. sometimes you don't have the question too.

you need to solve problem in the best way, and is never the way someone has teach you.

i see it everyday. no one that is a genius at school, is a genius outside school and vice versa.
Davide Bortolami,
Fermium LTD
 

Offline lemmegraphdat

  • Frequent Contributor
  • **
  • Posts: 273
  • Country: us
Re: Things derped engineers say.
« Reply #40 on: May 02, 2013, 10:14:49 pm »
OK, so...

A: This circuit needs 12V, 1A supply.
B: nice! I can give you this 12V 3A spare supply!
A:  :o are you mad? 3A would fry it!
B:  |O
I've had like conversations with someone who will remain nameless and I don't ever want to hear this kind of $#*! ever again from this person, it creeps me out.
Start right now.
 

Offline lemmegraphdat

  • Frequent Contributor
  • **
  • Posts: 273
  • Country: us
Re: Things derped engineers say.
« Reply #41 on: May 02, 2013, 10:47:34 pm »
Speaking of chocolate percentages.

You should try 99% chocolate sometime, It's crazy strong.

Almost impossible to chew without being overcome with bitterness. You have to let it dissolve on your tongue.

http://www.lindt.com/swf/eng/products/excellence/excellence-99/



I wonder how it is with bacon. Gonna try that. I'll let you know.
Start right now.
 

Offline c4757p

  • Super Contributor
  • ***
  • Posts: 7805
  • Country: us
  • adieu
Re: Things derped engineers say.
« Reply #42 on: May 02, 2013, 11:28:32 pm »
I wonder how it is with bacon. Gonna try that. I'll let you know.

Well, it can't possibly get any worse...  ::)
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline nuhamind2

  • Regular Contributor
  • *
  • Posts: 138
  • Country: id
Re: Things derped engineers say.
« Reply #43 on: May 03, 2013, 12:09:22 am »

Quote
F:What if we couple a generator to motor and power the motor from generator?
L:Power will be dissipated on the wire resistance

Well... technically true...
If it is me ,I'm gonna answer "You're not thinking about free energy ,are you?"
But still, I hope I never heard what my friend ask.
 

Online Dave

  • Super Contributor
  • ***
  • Posts: 1246
  • Country: si
  • I like to measure things.
Re: Things derped engineers say.
« Reply #44 on: May 03, 2013, 03:03:04 am »
you only need to do thing that someone has alredy teach you, and you need to do in the same way.
Wrong. You will see why, when you get to university.

When I was still in highschool, we had a teacher that taught us practical electronics. He was a know-it-all. At least he thought he was.
One day, we were messing with some opamp circuits, the teacher gave us TL072 opamps and pointed out, that those opamps were VERY rare (because he only happened to have 5 or 6 in his parts bin). My schoolmate managed to hook up the power supply in reverse (we only had red and black wires in the lab, he used red wires for both +12V and -12V line and - obviously - mixed them up) and the opamp gave up it's life with a loud pop. The teacher looked at my schoolmate with fear in his eyes and started whining that those opamps are rare and that now he won't have enough to show to other groups of students.
I was just about to order some stuff from Farnell that week and asked my schoolmate if he wanted me to pick up a couple of TL072s for him give back to the teacher. I did and next week my schoolmate gave two to our teacher. The teacher took those opamps and looked at them with amazement. "But they are SO rare, where did you find them?" I spoke up: "They sell them by the thousands at Farnell." The look on his face at that point was priceless. Disappointment, surprise and annoyance, all mixed together. :-DD
« Last Edit: May 03, 2013, 03:05:27 am by Dave »
<fellbuendel> it's arduino, you're not supposed to know anything about what you're doing
<fellbuendel> if you knew, you wouldn't be using it
 

Offline c4757p

  • Super Contributor
  • ***
  • Posts: 7805
  • Country: us
  • adieu
Re: Things derped engineers say.
« Reply #45 on: May 03, 2013, 04:17:46 am »
you only need to do thing that someone has alredy teach you, and you need to do in the same way.
Wrong. You will see why, when you get to university.

I think he's saying that's what you need to do to get through school, not that that's all you need to do in school to learn properly. Think - your teacher would have been perfectly happy to pass you if you all remained complete ignoramuses with regard to the availability of TL072, right?
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline ddavidebor

  • Super Contributor
  • ***
  • Posts: 1167
  • Country: gb
    • Fermium
Things derped engineers say.
« Reply #46 on: May 03, 2013, 07:38:19 am »
Yes, but learn properly + a good education is what, 90%?


...well, i've only 7/10 of average and i've ever had problem with autority of teacher.

But they treat me as the best student of the school.

So effectly what i've said is just for "standard" situation.
Davide Bortolami,
Fermium LTD
 

Offline T4P

  • Super Contributor
  • ***
  • Posts: 3706
  • Country: sg
    • T4P
Re: Things derped engineers say.
« Reply #47 on: May 03, 2013, 10:45:06 am »
Indeed, so-called top students (I was nearly top but not top so i'm not in the same category  ^-^) knows nothing else but the book ...  :palm:
He scored double distinctions but, ah f that  ::) He doesn't know shit about how things properly operate and thinks he's the best  :-//
When asked what's a quad matrix driver he has no idea  |O (FYI our teacher covered matrix displays the other and matrix drivers but he still has no idea  :scared: )

After the 2nd semester my class position has fallen to the center. Lucky me  :) No more being the center of attention ...  ;)
 

Online digsys

  • Supporter
  • ****
  • Posts: 2179
  • Country: au
    • DIGSYS
Re: Things derped engineers say.
« Reply #48 on: May 03, 2013, 11:04:26 am »
Long time ago I shared a factory with a high-end medical service / supply company (once had a DNA synthesiser in for commissioning !!)
One day a senior tech comes to me to ask for a fuse - give him the fuse and off he goes -
5 mins later, comes back asking for another fuse - ok, give him the fuse and off he goes -
5 mins later, comes back and asks for 10 fuses ! HUH? So I go back with him ... a large PILE of dead fuses on his bench?
I inquire ... Wassup mate ????
Reply: Every time I put a fuse in, it blows.
AND? Your conclusion is ????
Reply: Must be the fuses ! I need more ...
True
Hello <tap> <tap> .. is this thing on?
 

Offline free_electron

  • Super Contributor
  • ***
  • Posts: 7373
  • Country: us
    • SiliconValleyGarage
Re: Things derped engineers say.
« Reply #49 on: May 03, 2013, 03:12:51 pm »
I did one year of graduate course. They basically start again at zero ( ohms law) because a lot of people come in from other directions like latin-greek etc... Having had already 6 years electronics i was bored out of my skull . So i filled my time doing the seniors graduation projects, and annoying the non-teccies.

We just had seen the thermal calculation. Rthjc rthca et al... Dodo number one had a power supply with a 7805 and heatsink. It kept going in thermal protection . So he came to me for advice. Always up for a bit of fun i explained that increasing the surface of the heatsink would decrease the thermal resesitance rthca. . Case being the heatsink, a being ambient. So far so good. He nodded agreeingly..

But didnt have a larger heatsink. So i pulled in some other mathematics. Look at the thickness of the aluminum. If we were to drill a hole in there of the same diameter as the thickness. Lets say it is 1mm thick. The inner wall surface of that hole is thickness x diameter x pi . We only lost a bit of material in the hole ( on purpose i did not calculate what we lost , or it would have punctured the theory.. )

So dodo went off drilling lots of holes in his heatsink trying to get it to work. He spent an entire lab session (4 hours) on that.
Professional Electron Wrangler.
Any comments, or points of view expressed, are my own and not endorsed , induced or compensated by my employer(s).
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf