Despite being viable for a lot of the same applications, the difference between brush dc motors and brushless dc motors are not subtle.

The closest thing to a linear dc-dc power supply would be a dc motor driving a dc generator, which isn’t a very efficient proposition.

DC motors and AC motors accomplish this task in different ways. DC machines can be classified as self-excited, separately excited, permanent magnet (PM), and brushless. Self-excited machines can be ...