Blew my transformer - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 14th August 2004, 07:23 PM   #1
rs1026 is offline rs1026  India
diyAudio Member
 
Join Date: Jul 2004
Location: Bangalore
Angry Blew my transformer

Hi folks,
I was trying to build a amp based on stk 4192 II chip. Since 4192 accepts 8ohm loads.I connected two 4ohm full range speakers in series just to test the amp.

As soon as I turned the power the transformer went to smokes!!
But I could hear some music for 20sec or so. It sounded horrible. It was more noise than music.!

I used a 20-0-20,5amps rating transformer. I think it could not deliver sufficeint current hence got burnt out.

Any ideas what could be the reason and possible solutions.
Somehow I am not very sure of stk 4192's capability. Data sheet looks fine but I havent met anyone who tried using 4192.

Any suggestions??

Thanks,
  Reply With Quote
Old 14th August 2004, 08:02 PM   #2
djQUAN is offline djQUAN  Philippines
diyAudio Member
 
Join Date: May 2004
Location: manila
Send a message via MSN to djQUAN Send a message via Yahoo to djQUAN
probably oscillation or motorboating.
  Reply With Quote
Old 14th August 2004, 08:56 PM   #3
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Default Re: Blew my transformer

Quote:
Originally posted by rs1026
Hi folks,
I was trying to build a amp based on stk 4192 II chip. Since 4192 accepts 8ohm loads.I connected two 4ohm full range speakers in series just to test the amp.

As soon as I turned the power the transformer went to smokes!!
But I could hear some music for 20sec or so. It sounded horrible. It was more noise than music.!

I used a 20-0-20,5amps rating transformer. I think it could not deliver sufficeint current hence got burnt out.

Any ideas what could be the reason and possible solutions.
Somehow I am not very sure of stk 4192's capability. Data sheet looks fine but I havent met anyone who tried using 4192.

Any suggestions??

Thanks,
It is almost impossible to blow a transformer by overloading an amp. It really, really is extremely unlikely. Most probably there was either a problem with the transformer wiring or the rectifier (or the amp), in such a way that there was a dead short across the secondaries.

I would suggest to take out the transformer and see if it really is blown. 20 secs or so is not enough to blow a transformer, which can only be blown by thermal overload (and high-voltage overload, but that will not be the case here). And transformers have BIG thermal capacity. Take the naked transformer, separate out the wires to be sure there are no shorts, and apply mains (to the right terminals!) and measure the AC secondary voltage. Chances are it is OK. Then of course the real fun starts....

Jan Didden
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W. S. Maugham
Check out Linear Audio!
  Reply With Quote
Old 14th August 2004, 08:59 PM   #4
sss is offline sss  Israel
diyAudio Member
 
sss's Avatar
 
Join Date: Jul 2003
Location: Israel , haifa
Send a message via ICQ to sss
probably the bridge diodes are blown
  Reply With Quote
Old 15th August 2004, 08:29 PM   #5
Franz G is offline Franz G  Switzerland
diyAudio Member
 
Franz G's Avatar
 
Join Date: Jun 2004
Location: Bern / Switzerland
Could you show us your psu schematics please and how you connected the trafo?

Franz
  Reply With Quote
Old 15th August 2004, 11:06 PM   #6
karma is offline karma  Canada
diyAudio Member
 
karma's Avatar
 
Join Date: Feb 2003
Location: hamilton,ontario
Quote:
Originally posted by sss
probably the bridge diodes are blown

i second that

  Reply With Quote
Old 16th August 2004, 01:03 AM   #7
Banned
 
Join Date: Mar 2003
Location: Lisbon, Portugal
If you messed up the PSU connections to the chip, that is, you invert + with -, you may kill the trafo in seconds.
That's why you should always use a fuse in the primary, with the correct value.
The fuse would blow before the trafo.
  Reply With Quote
Old 16th August 2004, 07:49 AM   #8
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Quote:
Originally posted by carlosfm
If you messed up the PSU connections to the chip, that is, you invert + with -, you may kill the trafo in seconds.
That's why you should always use a fuse in the primary, with the correct value.
The fuse would blow before the trafo.

Beg to differ Carlos, you CANNOT blow a transformer in seconds. No way. Even a dead short on the secondaries (which as about as bad as it can get) will not do that. It takes time.

Jan Didden
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W. S. Maugham
Check out Linear Audio!
  Reply With Quote
Old 16th August 2004, 07:59 AM   #9
PMA is offline PMA  Europe
Design engineer, consultant
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
How about rated primary voltage of the transformer, does it fit to your local distribution network voltage?
  Reply With Quote
Old 16th August 2004, 09:32 AM   #10
Jean is offline Jean  United States
diyAudio Member
 
Jean's Avatar
 
Join Date: Mar 2002
Location: Sacramento, CA
Send a message via AIM to Jean
Quote:
Originally posted by janneman



Beg to differ Carlos, you CANNOT blow a transformer in seconds. No way. Even a dead short on the secondaries (which as about as bad as it can get) will not do that. It takes time.

Jan Didden
What he said
__________________
left lane is for passing, slower traffic keep right please.
  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
I think I blew up my t-amp...... help! tyler477 Class D 11 27th November 2008 01:34 AM
Fuse blew markiemrboo Chip Amps 30 21st November 2006 05:40 PM
blew up a UCD400. Why did it die? mp006ltk Class D 11 14th July 2006 10:46 PM
My tek 2235A just blew up the PSU cap pukka Parts 15 14th October 2004 01:05 PM


New To Site? Need Help?

All times are GMT. The time now is 12:13 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