The Hurst^® Stepping Motor Controller is a general purpose control and driver for 4-phase stepping motors rated at up to 500ma per phase.  It is fabricated using thick film hybrid technology and CMOS components, thus providing small size and low power consumption.  The hybrid may be operated with external power voltages from 6-24 Vdc.  It contains a regulator which provides an internal 5Vdc logic supply. 

The circuit includes a multivibrator which permits two modes of operation, continuous stepping at an adjustable frequency (RUN mode) or single steps (JOG mode).  The period of the multivibrator output is determined  by an external user supplied resistor and capacitor.  The pulse output and its compliment are available at the output terminals.

Pulses from the multivibrator or external or external pulses are connected to the PULSE IN terminal of the logic sequencer.  This circuitry generates 4-phases control signals in the conventional 2-on, 2-off sequence.  Direction of rotation is reversible and is determined by the state of the CW/CCW terminal.  In addition all 4 phases may be deenergized without interrupting the power supply by means of the DISABLE terminal.

The phases drivers are open collector transistors with maximum I_c and V_CEO ratings of 500ma and 80V respectively.  In applications which require larger phase currents, the phase drivers may be used to control power switching transistors.