Methods and apparatus for coding binary and multi-value sequences into higher value sequences are disclosed. The pulse width modulation system is configured to receive a control signal comprising a -bit binary word and to provide a pulse width modulated signal with a predetermined average duty cycle having a resolution of substantially 2\u2212. The controller portion collects the contents belonging to the same time range and having been detected by the content detector portion and that graphically displays on a display portion along a time series, graphical information related to the contents of the respective contents collected in units of the respective time range used when collecting the respective contents. Each stator tooth is spaced apart from each other by one of the stator slots.