LM2585: Transformer for the LM2585?

Hello,

I am struggling to find a suitable transformer for the LM2585. My needs are as follows:

1- input voltage 24V;

2 -output voltage 60V;

3- configuration: flyback;

4- power: 20W output

Currently I am using the WE 750313976, which works well but cannot handle more than 5W, and I don't seem to be able to find a commercial product capable of sustaining the 20W I need. So my questions are:

1- are you aware of any commercial transformers suitable for my needs?

2- if not, what parameters do you suggest for a custom transformer? I have experimented a bit building a few test transformers and I have determined that :

- the inductance of the primary winding to be between 50 and 100 uH; do you agree?

- the winding ratio between primary and secondary to be 1:4;

- I have tried a couple of different cores, but I have ben unable to determine exactly their composition; what core do you suggest and what size?

- what size should primary and secondary winding wires should be?

Thanks,

Paolo.