In Chapter 15 we discussed the hardware characteristics of bipolar and unipolar motors. From the circuit designer’s viewpoint, the fundamental difference between these motor types relates to the fact that bipolar motors contain a single winding per phase. Because there is a single winding, the current flow must be reversed in order for the rotor to turn. Another consequence of the bipolar motor structure is that the entire winding is activated during each cycle, while only half the winding is active in the unipolar design. Consequently, a bipolar motor generates more torque than a unipolar motor of the same size.