The system generates a direct current, so using it to power DC devices locally is more efficient than switching to the alternating current needed to feed it back to the grid.
该系统产生的电流为直流电，所以用来驱动本地的直流点装置比将其转化为交流电输入电网来的更有效率。
2
This system supplies water to boilers by alternating header pipes.
本系统采用切换母管制向锅炉供水。
3
By this method, we can design a data acquisition system in which an alternating pulse serves as the input signal with a microcomputer.