Author Topic: Missing transformer  (Read 1751 times)

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Offline GoatureTopic starter

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Missing transformer
« on: April 28, 2016, 06:20:15 pm »
Hello all!

I've been assigned the task of reviving this circuit board. When I received the board, only a few pieces of the transformer was remaining. I havent had much luck trying to find a similar transformer, and I was wondering you could help me on this.  :D

The footprint of the transformer is shown in the attached picture. The fuses are rated to 10A. The fuses appears connected in series with the primary of the transformer. The secondary is connected to a rectifier with the following ingraving: "F, T350, GBU, 8M", and then a 7818 regulator.

 

Offline SeanB

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Re: Missing transformer
« Reply #1 on: April 28, 2016, 06:56:59 pm »
Standard potted PCB mount transformer, likely a 220VAC primary and a dual 9VAC secondary, probably around 500mA rated. The 2 secondaries are in series, and the bridge rectifier probably delivers 24VDC to the regulator.
 

Offline promacjoe

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Re: Missing transformer
« Reply #2 on: April 29, 2016, 02:38:51 am »
Question: why would you need a 10 amp fuse on the primary side of a transformer, For a 1 A 18V regulator. There has to be something else on that circuit that requires 10A.
 

Offline SeanB

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Re: Missing transformer
« Reply #3 on: April 30, 2016, 10:46:01 am »
Those PCB mounted transformers are internally protected, likely there is a SCR or triac drive on the board which has the 10A fuse.

RS 347-2672 is a good place to start, looks like it will fit the holes and has the right pinout on it.
 

Offline Jeroen3

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Re: Missing transformer
« Reply #4 on: April 30, 2016, 11:15:08 am »
Maybe one of these:
http://www.gerth-trafo.de/images/PDF/datasheets/GERTH_Data_Series-600.pdf

They have plenty of transformers, they should be able to sell you a fitting one.
http://www.gerth-trafo.de/index.php/de/produkte
 


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