Blow out! :-) - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 19th September 2012, 08:06 PM   #1
KLR650 is offline KLR650  United Kingdom
diyAudio Member
 
Join Date: Aug 2012
Default Blow out! :-)

Pushed this effort a little too far ;-)

Glad I was several feet away when it went lol
Attached Images
File Type: jpg burn1.jpg (158.0 KB, 185 views)
  Reply With Quote
Old 19th September 2012, 08:14 PM   #2
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Kona, Hawaii
Blog Entries: 4
That is not a happy transistor!
  Reply With Quote
Old 19th September 2012, 08:21 PM   #3
adason is offline adason  United States
diyAudio Member
 
adason's Avatar
 
Join Date: Nov 2004
Location: Maryland
that capacitor looks even less happy, maybe thats what it all started...you breach the cap, you get dc where you do not want to, there goes transistor
  Reply With Quote
Old 19th September 2012, 08:22 PM   #4
tvrgeek is offline tvrgeek  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Md
Ah grasshopper, you must strive to keep the smoke inside the wires.
  Reply With Quote
Old 19th September 2012, 08:30 PM   #5
KLR650 is offline KLR650  United Kingdom
diyAudio Member
 
Join Date: Aug 2012
Quote:
Originally Posted by tvrgeek View Post
Ah grasshopper, you must strive to keep the smoke inside the wires.
But Master, I leave no trace on the rice paper! lol

I think I exceeded the power dissipation - worked fine 100V p to p and 500Hz but shortly after increasing to 1KHz it went (I'm driving a piezo stack). Exciting! :-)

BTW, I'm running it off +120V and -20V - hope this hasnt got anything to do with it?
  Reply With Quote
Old 19th September 2012, 09:24 PM   #6
diyAudio Member
 
Nico Ras's Avatar
 
Join Date: Nov 2005
Location: East Coast of South Africa
Quote:
Originally Posted by KLR650 View Post
But Master, I leave no trace on the rice paper! lol

I think I exceeded the power dissipation - worked fine 100V p to p and 500Hz but shortly after increasing to 1KHz it went (I'm driving a piezo stack). Exciting! :-)

BTW, I'm running it off +120V and -20V - hope this hasnt got anything to do with it?
Put a schematic up maybe we spot something. I may be mistaken but is an array of Piezo drivers not extremely capacitive?
__________________
Kindest regards
Nico
  Reply With Quote
Old 19th September 2012, 11:54 PM   #7
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
In the style of Mortal Kombat.... TOASTY!!
  Reply With Quote
Old 20th September 2012, 02:49 AM   #8
wg_ski is offline wg_ski  United States
diyAudio Member
 
Join Date: Oct 2007
Quote:
Originally Posted by KLR650 View Post
I think I exceeded the power dissipation - worked fine 100V p to p and 500Hz but shortly after increasing to 1KHz it went (I'm driving a piezo stack). Exciting! :-)

BTW, I'm running it off +120V and -20V - hope this hasnt got anything to do with it?
Most TO-220 transistors have absolutely horrible SOA above about 30V VCE. They may be only good for 5 or 10W (or volt-amps) driving a purely reactive load at those rail voltages. I'd start with something bigger, run the drivers at high bias and use base stoppers to avoid parametric oscillation (the burst-of-oscillation-on-part-of-the-cycle phenomenon).

It may have also gone into cross-conduction and then the current goes completely out of control. Speed differences between NPN and PNP show up with a vengence driving a capacitor.
  Reply With Quote
Old 20th September 2012, 06:55 AM   #9
KLR650 is offline KLR650  United Kingdom
diyAudio Member
 
Join Date: Aug 2012
Thanks for that.

I dont have a diagram to hand to post but I'm using a IRF630/9630 in a simple design - the bias set by a variable resistor but with a NTC thermistor in parallel to offer some thermal control of the bias. I'll try a more robust output pair and maybe have a low value resistor in series with the output for some isolation. Good fun though!
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
It will probably blow up blistard The Lounge 13 6th December 2011 09:35 PM
NAD fuses, slow blow or fast blow? AllCaster Solid State 3 25th October 2009 07:11 PM
Blow up once, Blow up twice and Blow up somemore S.C Chip Amps 14 6th March 2005 01:09 AM
Will This Blow Up? Trout Tubes / Valves 8 6th February 2005 01:52 PM
Will it blow up? dickerbeen Everything Else 1 17th April 2003 06:21 AM


New To Site? Need Help?

All times are GMT. The time now is 12:25 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2