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Transformer problem

Transformer problem

Transformer problem

(OP)
I have a Tranny with primary side 110v/230v and secondary side 16v/16v and 32v center tap. Problem is the first coil on the primary side is burnt out but the second coil is ok which is 320ohms on the primary side. Could I put a 320ohm resistor on the burnt coil to lower the voltage to 115v to the second coil so I can still get voltage out the secondary side coil. When tranny is on the control card and the jumper is set to 115v only one coil is used on the primary side they arnt connected in parallel. Any help appreciated as this card cost $1200.

RE: Transformer problem

Best option is to purchase an exact-replacement transformer from the OEM.

Next best option is to purchase an equivalent transformer with the same output voltages, etc.

The card may be worth $1200, but a transformer shouldn't cost that much.

In answer to your question, a resistor is a bad idea for several reasons. Perhaps a 240-to-120 'travel' transformer would be a better approach (not the diode version, the transformer version).

It's not recommended. The transformer with one winding damaged is 'walking wounded'. You don't know what other internal effects the damaged caused, perhaps it's nearly shorted primary to secondary. It's higher-than-acceptable risk to keep on using it.

 

RE: Transformer problem

If this is a USA manufactured PC board, try to match the transformer with one made by Signal transformer:

http://www.signaltransformer.com/

or

http://www.signaltransformer.com/content/split-bobbin–;low-power

Signal sells direct in units of one. I have repaired many boards using them.

You cannot use the DC resistance of the single primary as the replacement value for the primary. If you must use this board, find a 220 to 120 transformer and power the remaining primary. As noted above, this is a dangerous long term fix, as you don't really know when the damaged transformer will fail.

Steve
 

RE: Transformer problem

There is a good possibility that the damaged coil has turn to turn shorts. That would burn out the remaining primary coil very quickly. Replace the transformer.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Transformer problem

(OP)
Cool thanks dudes. I emailed the supplier and they said the remaining resistance on the primary coil is lower than a new one so yep it's damaged the remaining winding. I'll get a new one from America it costs $11.05 and the postage is $28 not so bad just hope it didn't spike the rest of the board and wreck the little caps and resistors. Thanks again  

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