Yung economic electromechanical DC governor during fence folding machine maintenance when the main tools in addition to the common multimeter, oscilloscope, logic analyzer, signal generator and other auxiliary maintenance equipment, and most importantly, is inseparable from the maintenance engineers experiences. A common fence folding machine DC governor maintenance features: governor voltage space vector / SVPWM based on the overall innate effect of the three-phase waveforms conditions, for the purpose of forced Pro motor air gap ideal circular rotating field trajectory, once born three-phase modulated waveform, less cut polygon forced Pro-round control. Then improved by practice use, that is, the introduction of the frequency compensation can eliminate the error of speed control; estimation of the magnitude of the flux through feedback to eliminate the impact of low speed stator resistance; the output voltage, current, closed-loop, advances in dynamic accuracy and not arbitrary degree. Second, the fence folding machine DC speed the maintenance control the way: 1, constant torque characteristics: general use curves like straight running conveyor belt, and speed has nothing to do constant torque use spaces; 2, decreasing torque characteristics: like a fan , water pumps, 2 power relationship between the load and speed were occasions, the use of such curves; 3, high starting torque: between the governor and the motor wiring interval is longer (about 100m) requirements start output torque than (lift the load), the governor's input or output AC reactor is inserted, with the motor running less than the maximum combined motor; 4, constant output power operation: the curve of its run at frequencies above 50Hz, 50Hz constant voltage. Yung economic electromechanical fence folding machine DC governor maintenance business is built on the basis of mutual trust with our customers, and strive for technical excellence, and has always been safe and reliable products for the repair is completed. Yung economic maintenance of the governor, is the choice of customers trusted.