Newbie asking about transformer - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 8th November 2013, 03:33 PM   #11
diyAudio Member
 
Max Martin's Avatar
 
Join Date: Apr 2011
Location: Sweden And Finland
I have almost the same toroid from a broken EAW caz 2500 (same as tapco juice 2500 and qsc rmx 2450)

I want to use it with some new class d design but as i'm a newbie in this area (mostly built speakers and done some mods on amps/dac/cds)

I wonder how i measure the voltage correctly on the secondary? Is it black probe to "0" and red to either "40" or "80"?

My transformer is 80-40-0-40-80 (times 2) like above. And 4,5A instead. Primary is 115-0-103-115v.

I'm think i'm confused because of this "0" and centre tap. Its not like crossovers at all
  Reply With Quote
Old 8th November 2013, 05:38 PM   #12
Minion is offline Minion  Canada
diyAudio Member
 
Join Date: May 2006
Location: Cowican Bay , vancouver island
The 0v is the center tap ..... They build a center tapped 40v 0v 40v transformer by making a 80v winding and connecting a wire at the very center of that winding which is the 0v thereby giving you 40v 0v 40v ....
  Reply With Quote
Old 8th November 2013, 10:19 PM   #13
diyAudio Member
 
Max Martin's Avatar
 
Join Date: Apr 2011
Location: Sweden And Finland
Quote:
Originally Posted by Minion View Post
The 0v is the center tap ..... They build a center tapped 40v 0v 40v transformer by making a 80v winding and connecting a wire at the very center of that winding which is the 0v thereby giving you 40v 0v 40v ....
So in my case with my toroid they have wind a 160 V winding (or actually two right?)

80-40-0-40-80
blu-pur-blk-pur-blu

then another;

80-40-0-40-80
whi-brn-blk-brn-whi

So can i get out 2x40V OR 2x80V max? Not both?

I'm still not sure how to measure it to be sure so it's working. Can I measure between for example pur-pur and the other brn-brn to see if i get about 40V?

I was thinking trying these new class D modules "Iraud350" which requires about 40-60 V. And hoped to use atleast two of them for stereo. Even better if i could use 4 pcs.

A link to them here:
Assembled IRAUD350 Mono Audio Power Amplifier Board Class D Amp Board | eBay

Anyway, thx for all your help =) Without this forum I would be lost =)
  Reply With Quote
Old 9th November 2013, 04:58 AM   #14
Minion is offline Minion  Canada
diyAudio Member
 
Join Date: May 2006
Location: Cowican Bay , vancouver island
In your case they built a 160v transformer with a center tap (0v with 80v on each side of 0v) They also tapped the winding at 40v so the 80v-40v-0v-40v-80v are all the same winding , and in your case you have 2 separate windings giving 80v-40v-0v-40v-80v .....

I don't have much experience with transformers that have 2 separate voltages on the same winding but my understanding tells me that you wouldn't want to run both the 80v and 40v windings at the same time though it would be fine to run one winding at 80v and the other at 40v .....

To measure the voltages is easy , on the first winding if you set you DMM to AC volts and put one probe on the black and the other on the blue you should get about 80 ish volts ..
From Black to Purple you should get 40v
From Blue to Blue 160V
From one blue to one purple 40v
From one blue to the other purple 120v

I have 2 similar boards to the ones you have I am about to power up , Im using a 600Va 42V 0V 42V transformer for a stereo setup so you should be fine using the 40v 0v 40v .....
  Reply With Quote
Old 9th November 2013, 07:58 AM   #15
diyAudio Member
 
Max Martin's Avatar
 
Join Date: Apr 2011
Location: Sweden And Finland
Ok thank you. I tested fast, with black probe to black cable and red to purple and my test leads/cable burned of and I didnt get any reading.

But I saw my test cable was poorly-made chinese so I made a new one that holds up but still dont get a reading... I got a bit afraid after this so I didn't test anymore. But will within a day or two.

If i look at the schematic for my now broken amp this transformer have been giving out after rectifier and smoothing caps, +55v -55v and +110 and -110V and also that extra 103V (for fan, leds and protection i think) (i have not connected that cable at all in primary side.

Thanks for a good explanation, simple and now I "get" it. 1-0 to the Canadian
  Reply With Quote
Old 9th November 2013, 03:46 PM   #16
diyAudio Member
 
Max Martin's Avatar
 
Join Date: Apr 2011
Location: Sweden And Finland
Ok, now I've measured all and yes it's working fine =)

Don't know how much difference/tolerance normally a toroid have. I got from 39,7V to 40,1 and 79.8V to 80,3V.

Is there anyway to calculate how "big" in VA this is? According to schematic it should be 1800VA but i doubt it. Weight is 7.6kg (16ib)
It seems that in my finnish friends amp (who started the thread) his is 1464VA from a T.amp with higher spec then mine.
  Reply With Quote
Old 12th November 2013, 04:40 PM   #17
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
I don't have a 1800VA to compare but my 1000VA weigh 6kg, so 1400 to 1800 is believable.

Can you tell if all the 40Vac and 8-Vac taps are from the same diameter of winding wire?
That same diameter tells you that all the taps operate at the same current.

If you use all the current capability of the 80Vac tap then there is no spare for the 40Vac tap.
Similarly if you use 100% of the 40Vac current, then none is left for the 80Vac tap.
You have to share the current in each of the part windings such that no single winding exceeds 100% of it's current rating.
__________________
regards Andrew T.
  Reply With Quote
Old 23rd November 2013, 02:13 PM   #18
diyAudio Member
 
Max Martin's Avatar
 
Join Date: Apr 2011
Location: Sweden And Finland
Ohh sorry, i missed andrewt's reply totally..

To answer your question,
- Hard to see. Alot of tape /insulation everywhere. All outcoming wires are 14awg accept the two black "0" are 12awg. When i look closely it seems like all wires are the same diameter. But i'm not sure...

I'm gonna try to use this "iraud350" modules (x2) with this toroid.
  Reply With Quote
Old 23rd November 2013, 05:41 PM   #19
diyAudio Member
 
Join Date: Jul 2013
Made by "me" transformer has been playing every day for several months to four pieces of ucd400hg amplifier.
With no problems.
The transformer does not heat up at all in practice, even taking out a lot of power.

Amplifier output power is 400w x4ch

Sorry. google translator...
  Reply With Quote
Old 4th January 2014, 11:02 AM   #20
diyAudio Member
 
Max Martin's Avatar
 
Join Date: Apr 2011
Location: Sweden And Finland
Here is my transformer together with Iraud 350/550 modules but one is not working at all (upper one). Maybe i've been connecting something wrong. Shouldn't they also be connected to earth /chassie from ex ground marking on board?? It works without though. Check next post. Can only upload one pic at a time with my iphone here...
Attached Images
File Type: jpg image.jpg (612.0 KB, 23 views)

Last edited by Max Martin; 4th January 2014 at 11:07 AM.
  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
Newbie Question - Power Transformer vs Isolation Transformer SparkyPete Tubes / Valves 10 2nd November 2012 06:13 PM
Newbie question about transformer? semi932 Power Supplies 2 24th May 2010 06:31 PM
transformer hookup for a newbie staggerlee Parts 2 14th January 2006 11:48 PM
Newbie Transformer question sachi Chip Amps 5 11th July 2005 06:59 AM


New To Site? Need Help?

All times are GMT. The time now is 02:14 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