Single axis A3977 stepper motor driver board for CNC Router Mill current 0-2A, ... adjustable current 0-2A rated output 2-phase bipolar stepper motor drive;2, standard parallel port interface, support for MACH2, ... 1 / 2,1 / 4,1 / 8;6, 12-36V single power supply switching power supply chips to use as a ... supply, stable and heat small;7, using RC +7414 automatic semi-flow;8, with a relay output to control the ...