... 3A-4.5A3.Mircostepping:1(1.8º),1/2,1/4,1/8,1/16,1/32,1/ ... machine not send out signal in half second, driver enter half current state of automatically for electricity saving ... When the double-phase electrical machinery is connected with driver , users are apt to connect the phase by ... , thus would damage the driver seriously. The protecting circuit is within this driver, when users connect by mistake ...