The problems in leakage protection and executive circuit of synthetical protection set in coal electric drill have been analyzed and calculated.
通过分析和计算说明老式煤电钻综合保护装置在漏电保护和执行电路中存在的问题。
2
RD auto pinning machine is used to make reference positioning pin prior to drill the laminated plates of etched circuit ca rd on drill machine for etched circuit ca rd manufacture premium products.