Author Topic: EEVsmoke #2  (Read 16159 times)

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Online EEVblog

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EEVsmoke #2
« on: November 06, 2016, 10:28:53 pm »
 
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Offline rs20

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Re: EEVsmoke #2
« Reply #1 on: November 07, 2016, 01:00:45 am »
Awesome stuff!!!

I'd really like to try replicating (and videoing) the captured-smoke failure. Seems like a worthy exception to the "natural failures only" rule  :)
« Last Edit: November 07, 2016, 04:45:39 am by rs20 »
 
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Offline Vgkid

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Re: EEVsmoke #2
« Reply #2 on: November 07, 2016, 04:15:27 am »
Some major self destruction, on this one.
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Offline SL4P

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Re: EEVsmoke #2
« Reply #3 on: November 07, 2016, 06:12:10 am »
Gives you an idea of how good coffee is for us!  ;)
They say cockroaches will survive a nuclear blast - but not an active coffee machine!
Don't ask a question if you aren't willing to listen to the answer.
 

Offline Halcyon

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Re: EEVsmoke #2
« Reply #4 on: November 07, 2016, 07:13:21 am »
Gives you an idea of how good coffee is for us!  ;)
They say cockroaches will survive a nuclear blast - but not an active coffee machine!

It looked more like a cricket to me.
 

Offline blackbird

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Re: EEVsmoke #2
« Reply #5 on: November 07, 2016, 09:03:15 am »
About the last picture of the escaped smoke (the Jaycar UPS), I noticed the most right component looks still OK, at least it has not exploded or burnt.

Could it be that because the most right one has a sil-pad underneath it survived, or better, because the other three does not had the sil-pads made them go 'booom'?
 

Offline G7PSK

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Re: EEVsmoke #2
« Reply #6 on: November 07, 2016, 09:19:59 am »
The fourth mosfet in the Jaycar UPS looked liked it had got rather hot as well. I once had a 400KVA gen set that had the insulation on the stator removed by ants, but unfortunately I do not have any photo's of it as it was quite a few years ago now.   
 

Offline lowimpedance

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Re: EEVsmoke #2
« Reply #7 on: November 07, 2016, 10:57:42 am »
The captured magic smoke is amazing, worth framing  :-+.
Also an interesting picture of the 'dark side of the moon' ......... well maybe not that dark!  :P
The odd multimeter or 2 or 3 or 4...or........can't remember !.
 

Offline EPTech

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Re: EEVsmoke #2
« Reply #8 on: November 07, 2016, 12:08:18 pm »
Hi there,

Nice episode. I remember now that this is the actual meaning of debugging, LMAF.  :-DD

I especially liked the power module that blew up "discretely", capturing the act in the gel, very nice. This would be difficult to recreate actually.

To dave: I would use your friends "joule bomb", not sure what the technical term it for that demonic device, the one you used on the multimeters. The trick would be to determine just the correct amount of energy not to blow up the IGBT completely but still have the effect of the smoke caputered in the gel. The setup itself is quiete simple. Hook up source and drain to the "joule bomb" and put an isolated control signal over gate-source to make it conduct, like a 9V battery. If the battery blows up with the rest, that is not a big loss.




Kind greetings,

Pascal.
 

Offline max_torque

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Re: EEVsmoke #2
« Reply #9 on: November 07, 2016, 03:09:50 pm »
Here's the DC link contactor that died alongside that IGBT from me:



Current monitor on DC link opened it automatically when IGBT shorted, but contactor had 850A flowing through it at the time!  Which it did break, but resulted in significant arc damage to the contactor contacts and cracked the porcelain of the housing.


Love the fact the contactor looks soo sad in the picture!   :-DD
 
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Offline vinicius.jlantunes

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Re: EEVsmoke #2
« Reply #10 on: November 07, 2016, 04:22:21 pm »
That magic smoke captured picture is mesmerizing... the video was good in its entirety but that picture alone would have made it worthy no doubt.

Offline Len

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Re: EEVsmoke #2
« Reply #11 on: November 07, 2016, 06:04:53 pm »
About the last picture of the escaped smoke (the Jaycar UPS), I noticed the most right component looks still OK, at least it has not exploded or burnt.

Could it be that because the most right one has a sil-pad underneath it survived, or better, because the other three does not had the sil-pads made them go 'booom'?

More likely, the one with the sil-pad failed previously and was replaced, that's why it's mounted differently, and then the other 3 failed.
 

Online blueskull

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Re: EEVsmoke #2
« Reply #12 on: November 07, 2016, 06:33:51 pm »
About the last picture of the escaped smoke (the Jaycar UPS), I noticed the most right component looks still OK, at least it has not exploded or burnt.

Could it be that because the most right one has a sil-pad underneath it survived, or better, because the other three does not had the sil-pads made them go 'booom'?

Looks like FET desaturation or core saturation to me. Simple overcurrent don't usually end up like this for FETs. It must be some gross overcurrent and overvoltage (desaturation) at the same time.
Many cheap power electronics do not have current sensor. They simply rely fuse to do average current protection, so FETs will not be turned off when desat happens.
 

Offline dansan

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Re: EEVsmoke #2
« Reply #13 on: November 07, 2016, 09:07:43 pm »
I can't be the only one who saw in that first example a Chinese emperor holding a Super Bowl trophy.
 
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Offline retrolefty

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Re: EEVsmoke #2
« Reply #14 on: November 07, 2016, 09:36:20 pm »
Cochrouch my ass, that's a grasshopper.  :-DMM
 

Offline electrophiliate

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Re: EEVsmoke #2
« Reply #15 on: November 08, 2016, 04:33:13 am »
The captured smoke in the IGBT gel is impressive.
Nothing is quite like a great humming power-station.
 

Offline EPTech

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Re: EEVsmoke #2
« Reply #16 on: November 08, 2016, 02:25:49 pm »
Here's the DC link contactor that died alongside that IGBT from me:



Current monitor on DC link opened it automatically when IGBT shorted, but contactor had 850A flowing through it at the time!  Which it did break, but resulted in significant arc damage to the contactor contacts and cracked the porcelain of the housing.


Love the fact the contactor looks soo sad in the picture!   :-DD

Hi there. I have not encountered a contactor like that in the drives I repaired, with the porcelain base I mean. Was it and older drive or maybe a high voltage one?
Kind greetings,

Pascal.
 

Offline SgtTech

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Re: EEVsmoke #2
« Reply #17 on: November 08, 2016, 08:09:20 pm »
Excellent stuff Dave, l like the magic smoke stuff. Maybe need to take another look at the multimeters you blew up! or maybe blow up a few more with a slow mo camera?
 

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Re: EEVsmoke #2
« Reply #18 on: November 08, 2016, 11:55:17 pm »
80k views, 5k thumbs, and a normal 5% thumbs down ratio.
So the segment seems very popular.
Although it could still be anomaly because of the awesome captured smoke photo.
 

Online Brumby

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Re: EEVsmoke #2
« Reply #19 on: November 09, 2016, 12:20:40 am »
You never know, this series might find a cult following.

But aside from that, I am beginning to warm to the content - and it's not because one of my photos was in there (but that didn't hurt  :D).

What is beginning to appeal to me is, I think, the dramatic nature of the failures - and the chances of seeing those one-in-a-million shots ... like the smoke captured in the gel.  That was just awesome.


I'll be interested to see how this theme tracks over time.
 

Online Brumby

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Re: EEVsmoke #2
« Reply #20 on: November 09, 2016, 12:25:21 am »
Anyone have some good examples of a MOV failure?

I had one, but I cleaned it up and repaired it.  A dead short across 240V makes for an interesting afternoon.
 

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Re: EEVsmoke #2
« Reply #21 on: November 09, 2016, 01:15:33 am »
What is beginning to appeal to me is, I think, the dramatic nature of the failures - and the chances of seeing those one-in-a-million shots ... like the smoke captured in the gel.  That was just awesome.
I'll be interested to see how this theme tracks over time.

Yes, will be interesting.
100% reliant upon viewer submission though, and to be honest there were a lot of submissions that really weren't worth showing IMO
 

Offline rrinker

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Re: EEVsmoke #2
« Reply #22 on: November 09, 2016, 01:05:02 pm »
 That captured smoke is going to be very hard to top. I'm with Lowimpedence - that's suitable for framing as art.

 

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Re: EEVsmoke #2
« Reply #23 on: November 09, 2016, 02:07:23 pm »
That captured smoke is going to be very hard to top.

It is.
 

Offline StuUK

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Re: EEVsmoke #2
« Reply #24 on: November 09, 2016, 02:11:04 pm »
80k views, 5k thumbs, and a normal 5% thumbs down ratio.
So the segment seems very popular.
Although it could still be anomaly because of the awesome captured smoke photo.

And the keywords in the title I suspect.....
 


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