design Idea 130

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Hi,

we have devlopment a led drive 4w for driving three LEDs at constant current.

we find very interesting the design idea 130 that use the TNY279p but for us is difficult do the trasformer with the information inside the document . Someone Can help us.

 

Regards,

Stefano

You may be able to construct the transformer based on the schematic and transformer parameter details which are given in the report. It appears that there is a mismatch on the primary winding pin-outs between the schematic (start:3, end:2) and transformer details (2-4).When you make the actual transformer, it doesn't matter where you terminate the windings, as long as you know where the start and end windings are terminated. 

 

Pin 1 in the schematic is just for cancellation winding and the unit should work even without it. But since it is used for EMI, you can utilize PI Expert to generate transformer construction document for TNY-III.