Another "can I use this transformer?" thread - Page 2 - 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 26th June 2012, 01:43 AM   #11
diyAudio Member
 
Join Date: Jan 2011
Location: Mexico
red to red: 1.2Ω
blue to blue: 0.7Ω
blue to red1: 0.5Ω
blue to red2: 1.0Ω
black to any red: 0.7Ω
black to any blue:: 0.5Ω

I guess: black is the center tap, blues are a middle point and red the far side?
  Reply With Quote
Old 26th June 2012, 02:45 AM   #12
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
Looks like it.

I had forgotten that you had 2x of some of the colors. Sorry.

To complete the picture, you should probably also refer to blue1 and blue2, instead of just "blue", in your post above.

So if you could, please also give measurements labeled as blue1 to red1, blue1 to red2, blue2 to red1, and blue2 to red2.

Did you short your probe tips together and measure that resistance, and then subtract that from each of your resistance measurements? (Also, check them shorted together, again, afterward, and if it's changed, re-do the measurements. Or, keep checking it until it stops changing, before starting the measurements, but then check it afterward, anyway.)

The reason I ask is because if black is the center, and black to each red is 0.7 Ohms, then red to red should be 1.4 Ohms, not 1.2. And blue to blue would be 1.0, not 0.7, since black to any blue is 0.5.

So it LOOKS like either we're wrong about how they are configured, or, the measurments are not accurate.

Or maybe I'm missing something, or looking at it wrong. But, enlarging your photo, I noticed that the secondary's PCB connector also has the wires in order, symmetrically, as red, blue, black, blue, red, which is the same order that we seem to be guessing that the taps are in.
  Reply With Quote
Old 26th June 2012, 03:49 AM   #13
diyAudio Member
 
Join Date: Jan 2011
Location: Mexico
Shorted leads: 0.3

Resistance with leads subtracted:

red1 to blue1: 0.2
red1 to black: 0.4
red1 to blue2: 0.7
red1 to red2: 0.9

blue1 to black: 0.2
blue1 to blue2: 0.4
blue1 to red2: 0.7

black to any blue: 0.2
black to any red: 0.4

blue2 to red2: 0.2

My meter only has 1 decimal, so it looks like the guess is right.
Blue to black 0.2 and blue to blue 0.4
Red to black 0.4 and red to red 0.9 (if my meter had 2 decimals, this could be confirmed).

What do you think?
  Reply With Quote
Old 26th June 2012, 04:27 AM   #14
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
If u have pulled it from a subwoofer, the components on the pcb that was powered by it, tell the specs of the transformer, better than anyone can guess. Your transformer is rated to drive the stk power amp u mentioned in the first post. Just refer the data for the stk and that will give u an idea of the power rating of the transformer (high current windings).

The smaller voltages were used for the low pass filter circuits, most probably designed around op-amps(may be discrete also).

Gajanan Phadte

Last edited by gmphadte; 26th June 2012 at 04:35 AM.
  Reply With Quote
Old 26th June 2012, 08:45 AM   #15
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Silver.
You must find which tappings are NOT connected to other tappings.
This allows you to label each winding and identify how many tappings are on each winding. A winding MUST have at least two tappings. A centre tapped winding MUST have at least three tappings.

First: find out how many windings you have.
Second: label the separate windings.
__________________
regards Andrew T.
  Reply With Quote
Old 26th June 2012, 01:27 PM   #16
diyAudio Member
 
Join Date: Jan 2011
Location: Mexico
Quote:
Originally Posted by AndrewT View Post
Silver.
You must find which tappings are NOT connected to other tappings.
This allows you to label each winding and identify how many tappings are on each winding. A winding MUST have at least two tappings. A centre tapped winding MUST have at least three tappings.

First: find out how many windings you have.
Second: label the separate windings.
Andrew, the transformer has 7 wires in the secondaries. They are separated in 2 bundles (separate connectors):
5 wires: red-blue-black-blue-red All of these seem to be the same winding (they all have continuity).
2 wires: yellow-yellow These are a separate winding.

I'm assuming that if they have continuity, they are part of the same winding, if that is incorrect, please let me know.
  Reply With Quote
Old 26th June 2012, 01:50 PM   #17
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
I can't tell you if they are the same winding. Only you can do that test.
Similarly for the primary or primaries.
You have to find which wires are connected and which groups do not connect to any other group.
You must do this FIRST !!!

I'm using "groups" instead of windings. Does that help?
__________________
regards Andrew T.
  Reply With Quote
Old 26th June 2012, 02:08 PM   #18
diyAudio Member
 
Join Date: Jan 2011
Location: Mexico
Now I'm confused, I "learned" a long time ago that if the wires have continuity are part of the same winding (please let me know if this is incorrect).

Based on this premise I tested for continuity the secondaries and primary.
Found that there is only 1 primary winding (all 5 wires have continuity).
There are 2 secondaries:
The red-blue-black-blue-red bundle is a single winding (all 5 wires have continuity).
The yellow-yellow pair is a separate winding (yellow-yellow have continuity, they have no continuity to other wire(s)).

Again, this is based on the premise that if they have continuity, they are part of the same winding. Is this premise incorrect?
  Reply With Quote
Old 26th June 2012, 02:34 PM   #19
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Good.
Now go back and re-read you measuring results. You should be able to see which bits of a winding are connected in what order from one end to the other.
__________________
regards Andrew T.
  Reply With Quote
Old 26th June 2012, 02:49 PM   #20
diyAudio Member
 
Join Date: Jan 2011
Location: Mexico
Quote:
Originally Posted by AndrewT View Post
Good.
Now go back and re-read you measuring results. You should be able to see which bits of a winding are connected in what order from one end to the other.
My uneducated guess is:
red1-2 are the beginning-end of the winding
black is the center
blue1-2 are somewhere midpoint between a red and the black
  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
diyAB Amp The "Honey Badger" build thread Variac Solid State 1184 21st August 2014 01:23 PM
SymAsym - "The Sequel", AAK's Rev_1.4 PCB Builders Thread AAK Solid State 142 24th December 2013 09:21 AM
SymAsym - "The Sequel", AAK's PCB Builders Thread AAK Solid State 219 3rd June 2012 04:21 PM
a thread for "resto-mod" turntables...(administrators/moderators please read) Nanook Analogue Source 26 15th February 2012 12:19 AM
"compact loudspeaker factory visit from "magico mini" thread Nanook Multi-Way 2 4th January 2008 07:30 AM


New To Site? Need Help?

All times are GMT. The time now is 03:47 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