Help Regarding Transformer Design

[saranonweb]

I need to build a transformer for 60kHz operation.It needs to have a turns ratio 1:5.And most importantly a magnetising inductance of 36uH.
I have choosen a core EE42

.
I have chosen a winding wire of SWG22 based on my current.
I want to know how I can get the above 36uH mutual inductance?
Should I wind on the middle leg(with primary and secondary over one another) or should I wind primary on one side and secondary on the other?

One of my friends suggested that I should first wind some turns on primary and check the inductance so that it is 36uH.then wind 5 times the number of primary turns at the secondary side.Is it the correct method?

Thanks

 

[Elvee]

In a power transformer, the primary number of turns is normally not governed by the magnetizing inductance (in resonant converters, it can be adjusted by varying the air gap), but by the core capacity or maximal induction (V*s or Tesla).
You need to know the forward voltage applied to the primary, the regime of operation (continuous, critical, discontinuous) and the topology: symetrical or else.
Once you know the minimum of turns required, you can compute the gap according to your magnetizing inductance requirement.
Also note that mutual and magnetizing inductances are completely different quantities.

 

[duncan999]

Assuming you have the right specs, then yes, that is the correct procedure. Wind enough turns on the bobbin (the black thing) to give you 36uH of magnetizing inductance. That is your primary. Now wind on a layer of Mylar tape, plumbers tape will do, and then wind on 5x the turns of the primary (on top of the tape so the windings are right on top of each other) to make the secondary. I think you meant to say "magnetizing inductance" when you said "mutual inductance".
Hope this helps.