# Stepper Motor Modes

A typical 4-wire stepper motors has 2 independent sets of coils, *A* and *B*.  A driver chip, which usually contains two full-bridge circuits, controls the amount and direction of current flowing through each coil.  When one or both coils are energized, a magnetic field is created with a repeating pattern of peaks and valleys

![fullStep2](images/fullStepTwoPhase.png)

![fullStep1](images/fullStepOnePhase.png)

![halfStep](images/halfStep.png)

![pwmSteps](images/StepperPWM.png)