Author Topic: Pot Blow-up  (Read 13994 times)

guysmiley

Pot Blow-up
« on: April 13, 2014, 10:42:44 AM »
So I was building a Atari Punk console and got it up and running and then a pot blew up.  Video of it happening here.  The pot seems to have stopped working, but the circuit still works.   Is this a common problem, or should I be worried about the circuits values that could have caused this?  Just bad luck?  I'm using mostly standard values everywhere, but used 500K pots and not 100K like the schematic had listed.  The circuit only works with a negative tipped 9v.  
« Last Edit: April 13, 2014, 11:04:03 AM by guysmiley »

Will.mendil

Re: Pot Blow-up
« Reply #1 on: April 13, 2014, 10:54:45 AM »
Wow that is a first time for me! Well I guess you should check for a short circuit. The way it burnt makes me think something caught fire in it. Check the voltages to see if nothing is higher than expected or inverted. But my opinion is that that was a faulty pot. I don't think it should happen again unless you are really unlucky.

Try opening it to see what is the damage inside. It is easy to open them just Lordy the tabs on the side and you'll see the "usually" graphite line with the whipper. If you could send some pictures. I am very curious

deadastronaut

Re: Pot Blow-up
« Reply #2 on: April 13, 2014, 10:58:23 AM »
blew up.. :icon_eek:

ive had one smoke on me on bvreaboard due to human error...but not explode....

guysmiley

Re: Pot Blow-up
« Reply #3 on: April 13, 2014, 11:05:16 AM »
I got the video posted above.  I guess the word blow-up is a bit strong.  There was a big flash and smoke.  I'll try to open it up. 

duck_arse

Re: Pot Blow-up
« Reply #4 on: April 13, 2014, 11:58:07 AM »
and that smell is to remind you not to do it again.

it looks as though you might have trapped the full supply across the wiper and one end of the pot. I've let the smoke out with a miswired wiper, but not as exciting as that. do you always video when you fiddle your pots?

guysmiley

Re: Pot Blow-up
« Reply #5 on: April 13, 2014, 01:44:04 PM »
No, I was just testing it and recorded that.

Jdansti

Re: Pot Blow-up
« Reply #6 on: April 13, 2014, 04:00:20 PM »
Cool!  Do it again!  :icon_twisted:

Just kidding-hope you figure it out.  :)

deadastronaut

Re: Pot Blow-up
« Reply #7 on: April 13, 2014, 04:13:20 PM »
^ ha ha, yeah i enjoyed watching that too.. :icon_twisted:

jimilee

Re: Pot Blow-up
« Reply #8 on: April 14, 2014, 12:16:22 AM »
Crazy,I've  had one glow and then melt down, it was pretty exciting... And then that smell...

Stinger

Re: Pot Blow-up
« Reply #9 on: April 23, 2014, 03:25:11 AM »
I had the exact same thing with one of my builds, can't even remember what was wrong with it, but yeah it was cool  :icon_twisted:

Will.mendil

Re: Pot Blow-up
« Reply #10 on: April 23, 2014, 04:21:24 AM »
Have you had the chance to open it? I curious to see if the graphite has burnt hence being the combustible

guysmiley

Re: Pot Blow-up
« Reply #11 on: April 26, 2014, 10:23:15 AM »
Well, here is the pot that blew.  Actually I blew another one.  I'm wondering what the hell is wrong?  How is the whole charge going to that pot?  It's a simple Atari Punk layout.  I had it working, now, not so much.

Will.mendil

Re: Pot Blow-up
« Reply #12 on: April 26, 2014, 10:40:54 AM »
Did the pots came from the same supplier? Might be a damaged batch. Maybe contact the seller

guysmiley

Re: Pot Blow-up
« Reply #13 on: April 26, 2014, 10:58:02 AM »
Went to an electronic shop, in two different visits.  I doubt it's a bad batch because of that and the other pot on the circuit is fine.  It's always the same posistioned pot that blows up. 

Jdansti

Re: Pot Blow-up
« Reply #14 on: April 26, 2014, 12:20:35 PM »
Post the link to the layout you're using and some photos of your board and maybe we can figure it out.  Note which pot is the one that's smoking.

GibsonGM

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Re: Pot Blow-up
« Reply #15 on: April 26, 2014, 08:18:17 PM »
That was awesome!  I love how you put your eye down to look right after, ha ha.    (The) Smoking pot is something we've all done, I think!

Strange to be having enough voltage getting to that pot for it to go postal.   Maybe the cap to ground from the "Freq 2" pot (pin 12) is shorted, allowing a full 9V to flow?  Or a similar thing with Freq 1, pin 1. If the 1K skips the 10nF there,  we have DC flowing to ground....

Good vid capture, that's kinda priceless!

guysmiley

Re: Pot Blow-up
« Reply #16 on: April 27, 2014, 08:34:36 AM »
I'm using this layout.
http://beavisaudio.com/bboard/projects/bbp_AtariPunkConsole_Rev_1_1.pdf
I'll try to get some pictures up soon.
The pot is the VR2 Freq 2 pot
« Last Edit: April 27, 2014, 08:49:16 AM by guysmiley »

guysmiley

Re: Pot Blow-up
« Reply #17 on: April 27, 2014, 09:28:49 AM »
Not sure how much anyone can see with these photos.  But here's whats going on.  It now doesn't work.




guysmiley

Re: Pot Blow-up
« Reply #19 on: April 27, 2014, 09:54:29 AM »
No offense taken.  I'm not good at working with small spaces and IC chips.  Maybe, I'll just get a vero board.  I haven't bread boarded this yet.  I should buy a bread board, it might save me some headaches.