WTB PSU Transformer Expert/Ace

Started by aje_fr, July 30, 2016, 08:39:50 AM

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aje_fr

Hello,
I have a PSU where one of the transformers is dead  :'(
So if someone replaced it's original PSU by a ATX and is willing to sell spare parts, let me know.
Transformer position is T2 and its ref is Q1716A2B
Let me save a 68k  ;)
Bye

caius

#1
Hi, are you sure its properly dead?It could be that some of the windings are broken internally or in the junction with pins, recently I have repaired one with this issue :

http://www.jammarcade.net/polar-toneohm-850-repair-log/

What do you measure on primary?Do you get nothing on secondary?

aje_fr

Caius  :o you are also there  ;)
Well, I'm sure that the transformer is dead because I tried to exchange it with another from a working psu, and all is fine now.
But it miss me one to repair the donor's one.

caius

Quote from: aje_fr on August 02, 2016, 06:44:46 AM
Caius  :o you are also there  ;)

Yes, my dear engineer, I'm also here, I'm your worst nightmare ;D

Quote
Well, I'm sure that the transformer is dead because I tried to exchange it with another from a working psu, and all is fine now.
But it miss me one to repair the donor's one.

OK.Are you able to figure out which is the VAC on the primary and what you get on secondary of the good transformer? (if it has one secondary winding, it could have more than one).Maybe we can try to look for a replacement.

aje_fr

Hello,
A little update,
I had "unwired" the bobbin, here is my measurement :

______
|   7 6 5|

  1 2 3 4
\______|


From the inner to the outside

Winding between 1 and 4 :
- 290 turns, with a ~0.16mm diameter enamelled copper

Winding between 5 and 6 :
- 18 turns, with a ~0.35mm diameter enamelled copper

Winding between 2 and 3
- 14 turns, with a ~0.16mm diameter enamelled copper

Bye

caius

Brilliant work, my dear engineer!
Now that you have measured the number of turns of windings , you could figure out which is the VAC on the output with the formula Vo = Vi/K  where Vo is output voltage   , Vi is the voltage input and K is N1/N2, so the relationship between the number of turns (N1) of the primary and the number of turns (N2) of secondary