Tom's right of course, my mistake, haste makes waste...... Thanks Tom !!!!
Look at that inductance equation.
A gap in the magnetic path adds a section of length with term μ of only 1 instead of the few thousand that's typical of transformer steel.
So it knocks inductance down smartly.
If you can find a transformer with say a winding good for 48volts at 3 amps
and add to it an air gap
that should do.
Sometimes transformers that look like this
have underneath that sheet metal wrapper a core that looks like this,