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If the motor needed smooth DC , you must use "H" bridge . Switch mode circuits are more powerful . You need only low cose bipolar transistors and a little bit of inductor . coils close to the value of the motors inductance will work . These self oscillating bipolar circuits will rise 10 amps into a motor in milliseconds . You only need to turn them off , they turn on by themselves . One circuit to drive the ground based motor , positive and another to drive it negative .

This circuit is far more fault tolerant and easier to control .

I cant understand why colleges dont teach these better methods . But i know why i left college after half a semester ! The proof is in commercial stuff like low cost power supplies . They only use 1) single bipolar , 2) self oscillating , 3) switch mode , "forward" converters, not fly backs .

I think its clever to nix the always present problem of driving the 1 vdc base of a bipolar . Its just a 2nd winding on the core ! Now i can fully saturate it for 90% efficiency , unlike your H bridge that needs a very large heat sink !

If your friends explain a complicated I.C. controlled "switcher" , it is NOT what im talking about .

Single bipolar , self-oscillating , and stopped by the simplist .03 amp control .