Standard equipment in industrial applications works with analog input voltages, either 0-5V, 0-10V or 2-10V. Using a current loop of 0-20 or 4-20mA at a burden resistor of 500Ω the resulting voltage is 0-10 or 2-10V.
Current loops are only used for long distance signal transmission. Up to 1,000m the voltage drop across a 0.8mm diameter wire and a current of a few µA is negligable, and can be compensated by offset correction.
Anyway, for your application you don't require to convert current to voltage. The toroidal transformer delivers voltage, not current.
Current is a matter of the connected load (burden) and in that particular case you use voltage directly at a high impedance input.
I'm getting confused reading your replies. It seems to me you expect a solution conformal with your idea (which I guess is the wrong approach).
Boncuk