How to calculate inductance of transformer primary coil - magnetization

chemelec

Well-Known Member

• Oct 7, 2012

• #21

I haven't ever used that IC, but I Believe that opa453 can only Drive 50 mA.
Not 200 mA.

And If your Transformers "Primary Impedance" is too Low, your Drive Voltage will be Pulled DOWN much lower.

So I would also make the primary, GREATER than 100uH.
Possibly even 500uH.

 

S

szzuk

Member

• Oct 7, 2012

• #22

Yes the fog is lifting, I've been making puny trafos.

It is the opa548, and can drive 3A. My memory is as good as those trafos!

 

chemelec

Well-Known Member

• Oct 7, 2012

• #23

The opa548 appears to be an Audio Amp.
And even though it claims to be up to 1 Mhz, Not sure it is good for your application.

You should check its output into a Low Resistive Load (around 200 Ohms) with a Oscilloscope.

 

S

szzuk

Member

• Oct 7, 2012

• #24

I regularly use the opa548 at these frequencies and voltages, it's been fine so far.

I will wind another trafo tomorrow if i get a chance. If I use some 0.2mm thick wire I might be able to re-use the EFD20's I have and save having to buy more bobbins and cores. Thanks, Szzuk.

 

dr pepper

Well-Known Member

Most Helpful Member

• Oct 8, 2012

• #25

When you get a bin full of copper wire and lines worn in your fingers from winding, then it'll work.