Traditionally used in applications for speed and positioning control these easy to drive motors are used in applications ranging from a few watts to several horse power. When only one direction of rotation is needed, a single transistor PWM can be used for speed control. For positioning applications or when both directions of rotation are needed, a full H-bridge with PWM control is used. At lower power levels the DC motor can be driven from a fully integrated power IC that includes the drivers and the power transistors. For higher power, discrete MOS or IGBT are used with high voltage gate drivers to implement the H-Bridge. A low cost microcontroller can be used to implement the speed control algorithm and to control the bridge. Accurate positioning or speed control require a sensor like a tach or an encoder. Simple speed adjustmentmay be obtained applying the open loop without feedback .