Stepper motors are brushless and very reliable since there are no contact brushes in the motor. A stepper motor is a digital version of the electric motor. The rotor moves in discrete steps as commanded, rather than rotating continuously like a conventional motor. A stepper motor, as its name suggests, moves one step at a time, unlike those conventional motors, which spin continuously. If a stepper motor is commanded to move some specific number of steps, it rotates incrementally that many number of steps and stops. Because of this basic nature of a stepper motor, it is widely used in low cost, open loop position control systems. Open loop control means no feedback information about the position is needed. The shaft or spindle of a stepper motor rotates in discrete step increments when electrical command pulses are applied to it in the proper sequence. The motor's rotation has several direct relationships to these applied input pulses. The sequence of the applied pulses is directly related to the direction of motor shaft's rotation. The speed of the motor shaft's rotation is directly related to the frequency of the input pulses and the length of rotation is directly related to the number of input pulses applied. Typical step angles range from 0.75° to 15°.