Calculation of transformers.
Step-up transformers for frequency f=10 kHz. Input resistance R=50 Ohm. Loads: 200 Ohm, 450 Ohm, 1250 Ohm. We select the inductance of the primary winding from the condition: L=(4...10) * R / (2*3.1415*f) = 6 mH, we select the number of turns, for example, 10 turns. Let the coupling coefficient of the windings be 0.99. Secondary windings: 10*sqr(200/50) =20, 10*sqr(450/50) =30, 10*sqr(1250/50) =50 turns.
The loads will have maximum power.
