国产的ＷＫ系列矿用挖掘机指令系统基本都是采用给 电桥供电，通过滑动变阻器的滑动来达到变压的目的，结构形式为在印刷电路板上焊接电阻，通过电刷在电路板上的滑动来达到切除或增加电阻的目的，这种结构形式的缺点是人所共知的，即碳刷容易磨损，需经常调整维护，电阻、印刷 Domestic WK series of mining excavator command system are basically used to power the bridge through the sliding rheostat sliding to achieve the purpose of transformation, the structure of the form of welding resistance on the printed circuit board, through the brush on the circuit board Sliding to achieve the purpose of cutting or increase the resistance, the disadvantage of this form of structure is well known that the carbon brush is easy to wear, often need to adjust the maintenance, resistance, printing