Stepper motors are integrated into applications where precise control is a basic operating requirement. From printers and vending machines, to industrial robots, stepper motors are often the only option. To achieve their precision, designers need to ensure that the rotor never loses synchronization as a result of stalling. In order to compensate, a current margin that is sufficient to prevent heavy torque changes, is normally used.
Application of a constant current results in a significant loss in drive efficiency. This extra, unused energy is dissipated in the stepper motor coils as heat, as well as in the electronic drive circuitry. It is possible to adjust the current applied by implementing real-time monitoring, but this requires significant design effort, sensing circuitry, and control algorithm development.