... positive poleNote:Must guard against exceeding 50V,so as not to damage the module2,GND:DC power cathode3,A+,A-: ... metal shell , or use axle flows fan dispels the heat, to make the module run reliably for a long time.2, Half ... electrical machinery is connected with driver , users are apt to connect the phase by mistake, thus would damage the driver ... driver,1.3A-4.5A,high quality and reasonable price