Don't use a motorized rheostat. You're going to have a big noisy device that wastes a lot of power.
I'd recommend that you get the PWM method working instead. Use transistors with lower on-resistance and make sure to use a good heat sink.
Don't use a motorized rheostat. You're going to have a big noisy device that wastes a lot of power.
I'd recommend that you get the PWM method working instead. Use transistors with lower on-resistance and make sure to use a good heat sink.