Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 2nd June 2008, 06:56 AM   #11
h_a is offline h_a  Europe
diyAudio Member
 
h_a's Avatar
 
Join Date: Sep 2006
Location: Graz, Austria
I have the impression that something is really wrong; either you accidentially shorted the secondaries or the toroid may have a tiny internal short.

100VA are no problem; indeed regulation is better with larger toroids, so don't worry at all about that.

I would not use a larger fuse! Nor a soft start circuit!

You have nothing connected to the secondaries, so that's the lightest load the psu will ever be. Find your fault first before going further.

My advice is check your toroid with a multimeter. Check resistance of primary and secondary windings.

How come you measure 34V without rectifying? Are you using a true RMS-multimeter? Or are these peak values? Don't forget DC-voltage will be 1.42*RMS value.

Have fun, Hannes
  Reply With Quote
Old 2nd June 2008, 01:46 PM   #12
diyAudio Member
 
Join Date: Mar 2003
Location: Central NY
I'm inclined to agree, Hannes. I certainly will not use a larger fuse. My DVM is not true RMS, in fact, it's about as cheap as you can get. But, I have access to good meters at work, so I'll check it out there.

But, in the interest of time, I think I will go ahead and order another, smaller, transformer.

I appreciate the help!
  Reply With Quote
Old 2nd June 2008, 03:55 PM   #13
Blues is offline Blues  United States
Lightning In A Bottle
diyAudio Member
 
Blues's Avatar
 
Join Date: Sep 2003
Location: The Milky Way
Quote:
Originally posted by Nelson Pass
Likely the polarity of one of your primary windings is reversed. That
will do it every time.

Quote:
Originally posted by Paul Ebert
....

To start, and until I can get parts in, could I simply use only one of the primary windings? ...
Have you tried the above like you described? Here's how you troubleshoot it to make sure it's just polarity reversal and not shorted toroid...

Without any load on the the toroid and with a fuse on one line of the primaries, and like you said..."simply use only one of the primary windings". If the fuse does not pop measure your secondary(ies). If the measurement is as advertised, unplug primaries and parallel second set of primaries. Plug paralleled primaries...if the fuse pops, unplug and reverse 2nd set of primaries. If the fuse does not pop go ahead and measure the secondaries and it should be the same as the first set of measurements. If the fuse still pops you have shorted primary windings...disconnect and buy a new transformer

allan
__________________
Leap into the Warpspeed wormhole... http://www.6moons.com/audioreviews/warpspeed/1.html
  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
Keep Blowing Fuses Whiting Tubes / Valves 9 11th September 2008 09:44 PM
Car Amp help? Fuses blowing... Tolo Car Audio 1 3rd December 2007 01:42 PM
Why are these fuses blowing Darin P-B Solid State 41 30th May 2005 10:56 PM
The Fuses Just Keep Blowing raffir Chip Amps 19 22nd June 2003 03:49 AM
Why does my PSU KEEP blowing fuses?! Rarkov Parts 29 17th October 2002 03:35 AM


New To Site? Need Help?

All times are GMT. The time now is 04:21 PM.


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