Crazy transformer? - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

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 5th January 2003, 11:53 AM   #1
diyAudio Member
 
Lisandro_P's Avatar
 
Join Date: Oct 2000
Location: Argentina
Send a message via ICQ to Lisandro_P
Default Crazy transformer?

I came across an old E-I 25v 3A transformer, small, which i beleive would be perfect for my preamp. The thing is it outputs 30VAC (give or take, measured with my multimeter) with no load at all, but when i connect it to a bridge rectifier it outputs 24VDC *and* about 12vAC on the output terminals. This happens both with a discrete bridge and a regular 30A one, so i beleive it's the trafo... but it's puzzling me. Any ideas what could be wrong here?
  Reply With Quote
Old 5th January 2003, 02:52 PM   #2
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
If you don't have any smoothing caps you will get DC AND AC! Varying DC voltage is in fact AC.

Nothing is wrong, just add smoothing caps!
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 5th January 2003, 02:59 PM   #3
diyAudio Member
 
Lisandro_P's Avatar
 
Join Date: Oct 2000
Location: Argentina
Send a message via ICQ to Lisandro_P
Thanks (feeling less dumb already)

BTW is that normal? I mean, 12vac it's almost 40% of the output. I have hooked bridges to transformers with no smoothing caps in the past and never had this kind of situations...
  Reply With Quote
Old 5th January 2003, 04:49 PM   #4
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Fullwave rectified AC has quite a lot of AC. Don't have the theoretical number in my head.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 5th January 2003, 04:54 PM   #5
diyAudio Member
 
Lisandro_P's Avatar
 
Join Date: Oct 2000
Location: Argentina
Send a message via ICQ to Lisandro_P
Once again, thanks!
  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
Going Crazy(er) rkernell Analogue Source 1 19th April 2009 11:48 PM
I'm going crazy, please help, Pic's Bensen Solid State 28 16th September 2004 05:11 PM
crazy idea... mekanoplastik Everything Else 12 6th January 2003 12:28 AM
Is this crazy? dc Multi-Way 25 20th October 2002 07:29 PM


New To Site? Need Help?

All times are GMT. The time now is 02:55 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